August 2003

Environmental Technology Verification Report

INDUSTRIAL TEST SYSTEMS INC QUICKtrade ULTRA LOW II TEST KIT

Prepared by

Battelle

Under a cooperative agreement with

US Environmental Protection Agency

August 2003

Environmental Technology Verification Report

ETV Advanced Monitoring Systems Center

Industrial Test Systems Inc Quicktrade Ultra Low II

Test Kitby

Tim Kaufman Patty WhiteAmy Dindal

Zachary WillenbergKaren Riggs

BattelleColumbus Ohio 43201

Notice

The US Environmental Protection Agency (EPA) through its Office of Research and Development has financially supported and collaborated in the extramural program described here This document has been peer reviewed by the Agency and recommended for public release Mention of trade names or commercial products does not constitute endorsement or recommendation by the EPA for use

ii

Foreword

The US Environmental Protection Agency (EPA) is charged by Congress with protecting the nationrsquos air water and land resources Under a mandate of national environmental laws the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life To meet this mandate the EPArsquos Office of Research and Development provides data and science support that can be used to solve environmental problems and to build the scientific knowledge base needed to manage our ecological resources wisely to understand how pollutants affect our health and to prevent or reduce environmental risks

The Environmental Technology Verification (ETV) Program has been established by the EPA to verify the performance characteristics of innovative environmental technology across all media and to report this objective information to permitters buyers and users of the technology thus substantially accelerating the entrance of new environmental technologies into the marketplace Verification organizations oversee and report verification activities based on testing and quality assurance protocols developed with input from major stakeholders and customer groups associated with the technology area ETV consists of seven environmental technology centers Information about each of these centers can be found on the Internet at httpwwwepagovetv

Effective verifications of monitoring technologies are needed to assess environmental quality and to supply cost and performance data to select the most appropriate technology for that assessment In 1997 through a competitive cooperative agreement Battelle was awarded EPA funding and support to plan coordinate and conduct such verification tests for ldquoAdvanced Monitoring Systems for Air Water and Soilrdquo and report the results to the community at large Information concerning this specific environmental technology area can be found on the Internet at httpwwwepagovetvcenterscenter1html

iii

August 2003

Environmental Technology Verification Report

ETV Advanced Monitoring Systems Center

Industrial Test Systems Inc Quicktrade Ultra Low II

Test Kitby

Tim Kaufman Patty WhiteAmy Dindal

Zachary WillenbergKaren Riggs

BattelleColumbus Ohio 43201

Notice

The US Environmental Protection Agency (EPA) through its Office of Research and Development has financially supported and collaborated in the extramural program described here This document has been peer reviewed by the Agency and recommended for public release Mention of trade names or commercial products does not constitute endorsement or recommendation by the EPA for use

ii

Foreword

The US Environmental Protection Agency (EPA) is charged by Congress with protecting the nationrsquos air water and land resources Under a mandate of national environmental laws the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life To meet this mandate the EPArsquos Office of Research and Development provides data and science support that can be used to solve environmental problems and to build the scientific knowledge base needed to manage our ecological resources wisely to understand how pollutants affect our health and to prevent or reduce environmental risks

The Environmental Technology Verification (ETV) Program has been established by the EPA to verify the performance characteristics of innovative environmental technology across all media and to report this objective information to permitters buyers and users of the technology thus substantially accelerating the entrance of new environmental technologies into the marketplace Verification organizations oversee and report verification activities based on testing and quality assurance protocols developed with input from major stakeholders and customer groups associated with the technology area ETV consists of seven environmental technology centers Information about each of these centers can be found on the Internet at httpwwwepagovetv

Effective verifications of monitoring technologies are needed to assess environmental quality and to supply cost and performance data to select the most appropriate technology for that assessment In 1997 through a competitive cooperative agreement Battelle was awarded EPA funding and support to plan coordinate and conduct such verification tests for ldquoAdvanced Monitoring Systems for Air Water and Soilrdquo and report the results to the community at large Information concerning this specific environmental technology area can be found on the Internet at httpwwwepagovetvcenterscenter1html

iii

Notice

The US Environmental Protection Agency (EPA) through its Office of Research and Development has financially supported and collaborated in the extramural program described here This document has been peer reviewed by the Agency and recommended for public release Mention of trade names or commercial products does not constitute endorsement or recommendation by the EPA for use

ii

Foreword

The US Environmental Protection Agency (EPA) is charged by Congress with protecting the nationrsquos air water and land resources Under a mandate of national environmental laws the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life To meet this mandate the EPArsquos Office of Research and Development provides data and science support that can be used to solve environmental problems and to build the scientific knowledge base needed to manage our ecological resources wisely to understand how pollutants affect our health and to prevent or reduce environmental risks

The Environmental Technology Verification (ETV) Program has been established by the EPA to verify the performance characteristics of innovative environmental technology across all media and to report this objective information to permitters buyers and users of the technology thus substantially accelerating the entrance of new environmental technologies into the marketplace Verification organizations oversee and report verification activities based on testing and quality assurance protocols developed with input from major stakeholders and customer groups associated with the technology area ETV consists of seven environmental technology centers Information about each of these centers can be found on the Internet at httpwwwepagovetv

Effective verifications of monitoring technologies are needed to assess environmental quality and to supply cost and performance data to select the most appropriate technology for that assessment In 1997 through a competitive cooperative agreement Battelle was awarded EPA funding and support to plan coordinate and conduct such verification tests for ldquoAdvanced Monitoring Systems for Air Water and Soilrdquo and report the results to the community at large Information concerning this specific environmental technology area can be found on the Internet at httpwwwepagovetvcenterscenter1html

iii

Foreword

The US Environmental Protection Agency (EPA) is charged by Congress with protecting the nationrsquos air water and land resources Under a mandate of national environmental laws the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life To meet this mandate the EPArsquos Office of Research and Development provides data and science support that can be used to solve environmental problems and to build the scientific knowledge base needed to manage our ecological resources wisely to understand how pollutants affect our health and to prevent or reduce environmental risks

The Environmental Technology Verification (ETV) Program has been established by the EPA to verify the performance characteristics of innovative environmental technology across all media and to report this objective information to permitters buyers and users of the technology thus substantially accelerating the entrance of new environmental technologies into the marketplace Verification organizations oversee and report verification activities based on testing and quality assurance protocols developed with input from major stakeholders and customer groups associated with the technology area ETV consists of seven environmental technology centers Information about each of these centers can be found on the Internet at httpwwwepagovetv

Effective verifications of monitoring technologies are needed to assess environmental quality and to supply cost and performance data to select the most appropriate technology for that assessment In 1997 through a competitive cooperative agreement Battelle was awarded EPA funding and support to plan coordinate and conduct such verification tests for ldquoAdvanced Monitoring Systems for Air Water and Soilrdquo and report the results to the community at large Information concerning this specific environmental technology area can be found on the Internet at httpwwwepagovetvcenterscenter1html

iii

Acknowledgments

The authors wish to acknowledge the support of all those who helped plan and conduct the verification test analyze the data and prepare this report In particular we would like to thank Rosanna Buhl Adam Abbgy and Bea Weaver of Battelle and Mike Madigan and Rick Linde of the Ayer Massachusetts Department of Public Works Water Division We also acknowledge the assistance of Jeff Adams of EPA and AMS Center stakeholders Vito Minei and Marty Link who reviewed the verification reports

iv

Contents

Page

Notice ii Foreword iii Acknowledgments ivList of Abbreviations viii

1 Background 1

2 Technology Description 2

3 Test Design and Procedures 431 Introduction 4 32 Test Design 4 33 Test Samples 5

331 QC Samples 5 332 PT Samples 7 333 Environmental Samples 7

34 Reference Analysis 835 Verification Schedule 8

4 Quality AssuranceQuality Control 10 41 Laboratory QC for Reference Method 10 42 Audits 13

421 Performance Evaluation Audit 13 422 Technical Systems Audit 13 423 Data Quality Audit 13

43 QAQC Reporting 14 44 Data Review 14

5 Statistical Methods 16 51 Accuracy 16 52 Precision 17 53 Linearity 17 54 Method Detection Limit 17 55 Matrix Interference Effects 18 56 Operator Bias 18 57 Inter-Unit Reproducibility 18 58 Rate of False PositivesFalse Negatives 18

v

6 Test Results 19 61 QC Samples 19 62 PT and Environmental Samples 23

621 Accuracy 23 622 Precision 25 623 Linearity 31 624 Method Detection Limit 34 625 Matrix Interference Effects 34 626 Operator Bias 35 627 Inter-Unit Reproducibility 35 628 Rate of False PositivesFalse Negatives 37

63 Other Factors 37 631 Ease of Use 37 632 Analysis Time 41 633 Reliability 41 634 Waste Material 41 635 Cost 41

7 Performance Summary 42

8 References 45

Figures

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit 2

Figure 2-2 Quicktrade Ultra Low II Color Chart 3

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results 33

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results 33

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results 34

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators 36

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade ArsenicScan and Compu-Scan Units 36

vi

Tables

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit 6

Table 3-2 Schedule of Verification Test Days 9

Table 4-1 Reference Method QCS Analysis Results 11

Table 4-2 Reference Method LFM Sample Results 12

Table 4-3 Reference Method Duplicate Analysis Results 12

Table 4-4 Reference Method PE Audit Results 13

Table 4-5 Summary of Data Recording Process 15

Table 6-1a RB Sample Results for the Technical Operator 20

Table 6-1b RB Sample Results for the Non-Technical Operator 20

Table 6-2a QCS Results for the Technical Operator 21

Table 6-2b QCS Results for the Non-Technical Operator 22

Table 6-3a LFM Sample Results for the Technical Operator 24

Table 6-3b LFM Sample Results for the Non-Technical Operator 25

Table 6-4 Quicktrade Ultra Low II Test Kit and Reference Sample Results 26

Table 6-5 Quantitative Evaluation of Accuracy for Quicktrade Ultra Low II Test Kits 29

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits 30

Table 6-7 Precision Results for Quicktrade Ultra Low II Test Kits 32

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit 35

Table 6-9 Rate of False Positives for Quicktrade Ultra Low II Test Kits 38

Table 6-10 Rate of False Negatives for Quicktrade Ultra Low II Test Kits 40

Table 7-1 Summary of Linear Regression Equations for Test Kit and Reference Results 43

vii

List of Abbreviations

AMS Advanced Monitoring Systems EPA US Environmental Protection Agency ETV Environmental Technology Verification HDPE high-density polyethylene ICPMS inductively coupled plasma mass spectrometry LFM laboratory-fortified matrix MDL method detection limit MSDS Material Safety Data Sheets NIST National Institute of Standards and Technology ppb parts per billion ppm parts per million PE performance evaluation PT performance test QA quality assurance QAQC quality assurancequality control QC quality control QCS quality control standard QMP Quality Management Plan RB reagent blank RPD relative percent difference RSD relative standard deviation TSA technical systems audit

viii

Chapter 1 Background

The US Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental techshynologies through performance verification and dissemination of information The goal of the ETV Program is to further environmental protection by accelerating the acceptance and use of improved and cost-effective technologies ETV seeks to achieve this goal by providing highshyquality peer-reviewed data on technology performance to those involved in the design distribution financing permitting purchase and use of environmental technologies

ETV works in partnership with recognized testing organizations with stakeholder groups consisting of buyers vendor organizations and permitters and with the full participation of individual technology developers The program evaluates the performance of innovative technologies by developing test plans that are responsive to the needs of stakeholders conducting field or laboratory tests (as appropriate) collecting and analyzing data and preparing peer-reviewed reports All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results are defensible

The EPArsquos National Exposure Research Laboratory and its verification organization partner Battelle operate the Advanced Monitoring Systems (AMS) Center under ETV The AMS Center recently evaluated the performance of the Industrial Test Systems Inc Quicktrade Ultra Low II test kit for measuring arsenic in water

1

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Contents

Page

Notice ii Foreword iii Acknowledgments ivList of Abbreviations viii

1 Background 1

2 Technology Description 2

3 Test Design and Procedures 431 Introduction 4 32 Test Design 4 33 Test Samples 5

331 QC Samples 5 332 PT Samples 7 333 Environmental Samples 7

34 Reference Analysis 835 Verification Schedule 8

4 Quality AssuranceQuality Control 10 41 Laboratory QC for Reference Method 10 42 Audits 13

421 Performance Evaluation Audit 13 422 Technical Systems Audit 13 423 Data Quality Audit 13

43 QAQC Reporting 14 44 Data Review 14

5 Statistical Methods 16 51 Accuracy 16 52 Precision 17 53 Linearity 17 54 Method Detection Limit 17 55 Matrix Interference Effects 18 56 Operator Bias 18 57 Inter-Unit Reproducibility 18 58 Rate of False PositivesFalse Negatives 18

v

6 Test Results 19 61 QC Samples 19 62 PT and Environmental Samples 23

621 Accuracy 23 622 Precision 25 623 Linearity 31 624 Method Detection Limit 34 625 Matrix Interference Effects 34 626 Operator Bias 35 627 Inter-Unit Reproducibility 35 628 Rate of False PositivesFalse Negatives 37

63 Other Factors 37 631 Ease of Use 37 632 Analysis Time 41 633 Reliability 41 634 Waste Material 41 635 Cost 41

7 Performance Summary 42

8 References 45

Figures

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit 2

Figure 2-2 Quicktrade Ultra Low II Color Chart 3

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results 33

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results 33

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results 34

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators 36

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade ArsenicScan and Compu-Scan Units 36

vi

Tables

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit 6

Table 3-2 Schedule of Verification Test Days 9

Table 4-1 Reference Method QCS Analysis Results 11

Table 4-2 Reference Method LFM Sample Results 12

Table 4-3 Reference Method Duplicate Analysis Results 12

Table 4-4 Reference Method PE Audit Results 13

Table 4-5 Summary of Data Recording Process 15

Table 6-1a RB Sample Results for the Technical Operator 20

Table 6-1b RB Sample Results for the Non-Technical Operator 20

Table 6-2a QCS Results for the Technical Operator 21

Table 6-2b QCS Results for the Non-Technical Operator 22

Table 6-3a LFM Sample Results for the Technical Operator 24

Table 6-3b LFM Sample Results for the Non-Technical Operator 25

Table 6-4 Quicktrade Ultra Low II Test Kit and Reference Sample Results 26

Table 6-5 Quantitative Evaluation of Accuracy for Quicktrade Ultra Low II Test Kits 29

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits 30

Table 6-7 Precision Results for Quicktrade Ultra Low II Test Kits 32

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit 35

Table 6-9 Rate of False Positives for Quicktrade Ultra Low II Test Kits 38

Table 6-10 Rate of False Negatives for Quicktrade Ultra Low II Test Kits 40

Table 7-1 Summary of Linear Regression Equations for Test Kit and Reference Results 43

vii

List of Abbreviations

AMS Advanced Monitoring Systems EPA US Environmental Protection Agency ETV Environmental Technology Verification HDPE high-density polyethylene ICPMS inductively coupled plasma mass spectrometry LFM laboratory-fortified matrix MDL method detection limit MSDS Material Safety Data Sheets NIST National Institute of Standards and Technology ppb parts per billion ppm parts per million PE performance evaluation PT performance test QA quality assurance QAQC quality assurancequality control QC quality control QCS quality control standard QMP Quality Management Plan RB reagent blank RPD relative percent difference RSD relative standard deviation TSA technical systems audit

viii

Chapter 1 Background

The US Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental techshynologies through performance verification and dissemination of information The goal of the ETV Program is to further environmental protection by accelerating the acceptance and use of improved and cost-effective technologies ETV seeks to achieve this goal by providing highshyquality peer-reviewed data on technology performance to those involved in the design distribution financing permitting purchase and use of environmental technologies

ETV works in partnership with recognized testing organizations with stakeholder groups consisting of buyers vendor organizations and permitters and with the full participation of individual technology developers The program evaluates the performance of innovative technologies by developing test plans that are responsive to the needs of stakeholders conducting field or laboratory tests (as appropriate) collecting and analyzing data and preparing peer-reviewed reports All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results are defensible

The EPArsquos National Exposure Research Laboratory and its verification organization partner Battelle operate the Advanced Monitoring Systems (AMS) Center under ETV The AMS Center recently evaluated the performance of the Industrial Test Systems Inc Quicktrade Ultra Low II test kit for measuring arsenic in water

1

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

6 Test Results 19 61 QC Samples 19 62 PT and Environmental Samples 23

621 Accuracy 23 622 Precision 25 623 Linearity 31 624 Method Detection Limit 34 625 Matrix Interference Effects 34 626 Operator Bias 35 627 Inter-Unit Reproducibility 35 628 Rate of False PositivesFalse Negatives 37

63 Other Factors 37 631 Ease of Use 37 632 Analysis Time 41 633 Reliability 41 634 Waste Material 41 635 Cost 41

7 Performance Summary 42

8 References 45

Figures

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit 2

Figure 2-2 Quicktrade Ultra Low II Color Chart 3

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results 33

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results 33

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results 34

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators 36

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade ArsenicScan and Compu-Scan Units 36

vi

Tables

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit 6

Table 3-2 Schedule of Verification Test Days 9

Table 4-1 Reference Method QCS Analysis Results 11

Table 4-2 Reference Method LFM Sample Results 12

Table 4-3 Reference Method Duplicate Analysis Results 12

Table 4-4 Reference Method PE Audit Results 13

Table 4-5 Summary of Data Recording Process 15

Table 6-1a RB Sample Results for the Technical Operator 20

Table 6-1b RB Sample Results for the Non-Technical Operator 20

Table 6-2a QCS Results for the Technical Operator 21

Table 6-2b QCS Results for the Non-Technical Operator 22

Table 6-3a LFM Sample Results for the Technical Operator 24

Table 6-3b LFM Sample Results for the Non-Technical Operator 25

Table 6-4 Quicktrade Ultra Low II Test Kit and Reference Sample Results 26

Table 6-5 Quantitative Evaluation of Accuracy for Quicktrade Ultra Low II Test Kits 29

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits 30

Table 6-7 Precision Results for Quicktrade Ultra Low II Test Kits 32

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit 35

Table 6-9 Rate of False Positives for Quicktrade Ultra Low II Test Kits 38

Table 6-10 Rate of False Negatives for Quicktrade Ultra Low II Test Kits 40

Table 7-1 Summary of Linear Regression Equations for Test Kit and Reference Results 43

vii

List of Abbreviations

AMS Advanced Monitoring Systems EPA US Environmental Protection Agency ETV Environmental Technology Verification HDPE high-density polyethylene ICPMS inductively coupled plasma mass spectrometry LFM laboratory-fortified matrix MDL method detection limit MSDS Material Safety Data Sheets NIST National Institute of Standards and Technology ppb parts per billion ppm parts per million PE performance evaluation PT performance test QA quality assurance QAQC quality assurancequality control QC quality control QCS quality control standard QMP Quality Management Plan RB reagent blank RPD relative percent difference RSD relative standard deviation TSA technical systems audit

viii

Chapter 1 Background

The US Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental techshynologies through performance verification and dissemination of information The goal of the ETV Program is to further environmental protection by accelerating the acceptance and use of improved and cost-effective technologies ETV seeks to achieve this goal by providing highshyquality peer-reviewed data on technology performance to those involved in the design distribution financing permitting purchase and use of environmental technologies

ETV works in partnership with recognized testing organizations with stakeholder groups consisting of buyers vendor organizations and permitters and with the full participation of individual technology developers The program evaluates the performance of innovative technologies by developing test plans that are responsive to the needs of stakeholders conducting field or laboratory tests (as appropriate) collecting and analyzing data and preparing peer-reviewed reports All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results are defensible

The EPArsquos National Exposure Research Laboratory and its verification organization partner Battelle operate the Advanced Monitoring Systems (AMS) Center under ETV The AMS Center recently evaluated the performance of the Industrial Test Systems Inc Quicktrade Ultra Low II test kit for measuring arsenic in water

1

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tables

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit 6

Table 3-2 Schedule of Verification Test Days 9

Table 4-1 Reference Method QCS Analysis Results 11

Table 4-2 Reference Method LFM Sample Results 12

Table 4-3 Reference Method Duplicate Analysis Results 12

Table 4-4 Reference Method PE Audit Results 13

Table 4-5 Summary of Data Recording Process 15

Table 6-1a RB Sample Results for the Technical Operator 20

Table 6-1b RB Sample Results for the Non-Technical Operator 20

Table 6-2a QCS Results for the Technical Operator 21

Table 6-2b QCS Results for the Non-Technical Operator 22

Table 6-3a LFM Sample Results for the Technical Operator 24

Table 6-3b LFM Sample Results for the Non-Technical Operator 25

Table 6-4 Quicktrade Ultra Low II Test Kit and Reference Sample Results 26

Table 6-5 Quantitative Evaluation of Accuracy for Quicktrade Ultra Low II Test Kits 29

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits 30

Table 6-7 Precision Results for Quicktrade Ultra Low II Test Kits 32

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit 35

Table 6-9 Rate of False Positives for Quicktrade Ultra Low II Test Kits 38

Table 6-10 Rate of False Negatives for Quicktrade Ultra Low II Test Kits 40

Table 7-1 Summary of Linear Regression Equations for Test Kit and Reference Results 43

vii

List of Abbreviations

AMS Advanced Monitoring Systems EPA US Environmental Protection Agency ETV Environmental Technology Verification HDPE high-density polyethylene ICPMS inductively coupled plasma mass spectrometry LFM laboratory-fortified matrix MDL method detection limit MSDS Material Safety Data Sheets NIST National Institute of Standards and Technology ppb parts per billion ppm parts per million PE performance evaluation PT performance test QA quality assurance QAQC quality assurancequality control QC quality control QCS quality control standard QMP Quality Management Plan RB reagent blank RPD relative percent difference RSD relative standard deviation TSA technical systems audit

viii

Chapter 1 Background

The US Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental techshynologies through performance verification and dissemination of information The goal of the ETV Program is to further environmental protection by accelerating the acceptance and use of improved and cost-effective technologies ETV seeks to achieve this goal by providing highshyquality peer-reviewed data on technology performance to those involved in the design distribution financing permitting purchase and use of environmental technologies

ETV works in partnership with recognized testing organizations with stakeholder groups consisting of buyers vendor organizations and permitters and with the full participation of individual technology developers The program evaluates the performance of innovative technologies by developing test plans that are responsive to the needs of stakeholders conducting field or laboratory tests (as appropriate) collecting and analyzing data and preparing peer-reviewed reports All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results are defensible

The EPArsquos National Exposure Research Laboratory and its verification organization partner Battelle operate the Advanced Monitoring Systems (AMS) Center under ETV The AMS Center recently evaluated the performance of the Industrial Test Systems Inc Quicktrade Ultra Low II test kit for measuring arsenic in water

1

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

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(con

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Sam

ple

ID

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Pos

itive

(YN

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hart

Tech

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Qui

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Tech

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olor

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an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

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32

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32

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tal f

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2 1

5 8

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39

Tab

le 6

-10

Rat

e of

Fal

se N

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ives

for

Qui

cktrade

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a Lo

w II

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Des

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Sam

ple

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e N

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(YN

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30

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As

CA

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9 C

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-29

CA

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9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

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Aye

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C

AA

-39

CA

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9

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LFM

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AA

-40

1 N

N

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LFM

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AA

-42

1 N

N

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Y

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Y

Fa

lmou

th P

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FM

CA

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6 1

Y

Y

Y

Y

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Y

Taun

ton

Riv

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LFM

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AA

-48

1 N

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10

ppb

As +

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rfer

ents

CA

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5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

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Tota

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f sam

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21

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40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

List of Abbreviations

AMS Advanced Monitoring Systems EPA US Environmental Protection Agency ETV Environmental Technology Verification HDPE high-density polyethylene ICPMS inductively coupled plasma mass spectrometry LFM laboratory-fortified matrix MDL method detection limit MSDS Material Safety Data Sheets NIST National Institute of Standards and Technology ppb parts per billion ppm parts per million PE performance evaluation PT performance test QA quality assurance QAQC quality assurancequality control QC quality control QCS quality control standard QMP Quality Management Plan RB reagent blank RPD relative percent difference RSD relative standard deviation TSA technical systems audit

viii

Chapter 1 Background

The US Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental techshynologies through performance verification and dissemination of information The goal of the ETV Program is to further environmental protection by accelerating the acceptance and use of improved and cost-effective technologies ETV seeks to achieve this goal by providing highshyquality peer-reviewed data on technology performance to those involved in the design distribution financing permitting purchase and use of environmental technologies

ETV works in partnership with recognized testing organizations with stakeholder groups consisting of buyers vendor organizations and permitters and with the full participation of individual technology developers The program evaluates the performance of innovative technologies by developing test plans that are responsive to the needs of stakeholders conducting field or laboratory tests (as appropriate) collecting and analyzing data and preparing peer-reviewed reports All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results are defensible

The EPArsquos National Exposure Research Laboratory and its verification organization partner Battelle operate the Advanced Monitoring Systems (AMS) Center under ETV The AMS Center recently evaluated the performance of the Industrial Test Systems Inc Quicktrade Ultra Low II test kit for measuring arsenic in water

1

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 1 Background

The US Environmental Protection Agency (EPA) supports the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative environmental techshynologies through performance verification and dissemination of information The goal of the ETV Program is to further environmental protection by accelerating the acceptance and use of improved and cost-effective technologies ETV seeks to achieve this goal by providing highshyquality peer-reviewed data on technology performance to those involved in the design distribution financing permitting purchase and use of environmental technologies

ETV works in partnership with recognized testing organizations with stakeholder groups consisting of buyers vendor organizations and permitters and with the full participation of individual technology developers The program evaluates the performance of innovative technologies by developing test plans that are responsive to the needs of stakeholders conducting field or laboratory tests (as appropriate) collecting and analyzing data and preparing peer-reviewed reports All evaluations are conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data of known and adequate quality are generated and that the results are defensible

The EPArsquos National Exposure Research Laboratory and its verification organization partner Battelle operate the Advanced Monitoring Systems (AMS) Center under ETV The AMS Center recently evaluated the performance of the Industrial Test Systems Inc Quicktrade Ultra Low II test kit for measuring arsenic in water

1

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 2 Technology Description

The objective of the ETV AMS Center is to verify the performance characteristics of environmental monitoring technologies for air water and soil This verification report provides results for the verification testing of the Quicktrade Ultra Low II test kit for arsenic in water Following is a description of the test kit based on information provided by the vendor The information provided below was not verified in this test The test kit components are shown in Figure 2-1

To perform arsenic analyses with the Quicktrade Ultra Low II test kit the water sample to be tested is mixed in the supplied reaction vessel with reagent 1 (tartaric acid with rate enhancers) to acidify the water sample Reagent 2 an oxidizer (potassium peroxymonosulfate) is added to remove hydrogen sulfide interference The test tolerates up to 2 parts per million (ppm) hydrogen sulfide without interference Zinc powder reagent 3 is added to reduce inorganic arsenic compounds (As+3 and As+5) to arsine gas As arsine gas is generated and comes in contact with the test strip the mercuric bromide indicator on the test strip changes color from white to shades of yellow or brown

Material Safety Data Sheets (MSDSs) for all reagents and test strips are provided with each test kit The MSDSs include information on how to safely handle the reagents and test strips including instructions for exposure controls and personal protection

Once the reaction is completed the test strip is removed and visually compared to a color chart to obtain a semishyquantitative measure of the arsenic concentration in the tested sample The color chart consists of a series of color blocks (Figure 2-2) The color blocks correspond to concentrations ranging from 04 parts per billion (ppb) to gt25 ppb If the color on the test strip is

between two color blocks then the operator may estimate the concentration as between the two values associated with the color blocks on either side

Figure 2-1 Industrial Test Systems Inc Quicktrade Ultra Low II Test Kit

2

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Figure 2-2 Quicktrade Ultra Low II Color Chart

The test strip may also be read with the Quicktrade Arsenic Scan hand-held instrument which operates on the same principle as a colorimeter and provides a quantitative result The Quicktrade Arsenic Scan is calibrated weekly using a card provided by the manufacturer Quantitative results may also be obtained from the test strip with a portable Compu-Scan scanner and laptop computer system The scanned test strip image is converted to an arsenic concentration using the Home Port Computer System Arsenic Program Revision 5b software program The scanner is calibrated by the manufacturer The Quicktrade Arsenic Scan and Compu-Scan are not provided with the Quicktrade Ultra Low II test kit as a standard feature The standard test kit with the color chart was the subject of the verification test however results for the Quicktrade Arsenic Scan and Compu-Scan are also provided

The optimal detection range for the Quicktrade Ultra Low II test kit is below 4 ppb Dilution instructions are provided for samples with arsenic levels above 4 ppb The recommended temperature range for sample analysis is 24degC to 30degC A modified testing protocol that specifies longer reaction times (up to 30 minutes longer for samples between 5deg-15degC) is available for sample temperatures below this range

The Quicktrade Ultra Low II test kit is available in sets of 50 tests The typical shelf life of the kits is 24 months

3

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 3 Test Design and Procedures

31 Introduction

This verification test was conducted according to procedures specified in the TestQA Plan for Verification of Portable Analyzers(1) The verification was based on comparing the arsenic results from the Quicktrade Ultra Low II test kit to those from a laboratory-based reference method The reference method for arsenic analysis was inductively coupled plasma mass spectrometry (ICPMS) performed according to EPA Method 2008(2) The Quicktrade Ultra Low II test kit relies on comparisons to a color chart provided with the test kit to allow semi-quantitative measurements of arsenic concentrations Quantitative results were also obtained from a Quicktrade Arsenic Scan instrument and Compu-Scan system The test kit performance was verified by analyzing laboratory-prepared performance test samples treated and untreated drinking water and fresh surface water All samples were tested using both the test kit and the reference method Both semi-quantitative and quantitative analyses were performed by the technical and nonshytechnical operators The test design and procedures are described below

32 Test Design

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity Method detection limit (MDL) Matrix interference effects Operator bias Inter-unit reproducibility Rate of false positivesfalse negatives

All sample preparation and analyses were performed according to the manufacturerrsquos recommended procedures All samples were warmed to 24degC prior to analysis using a hot water bath which is at the lower end of the optimal temperature range listed in the test kit instructions Color chart Quicktrade Arsenic Scan and Compu-Scan results were recorded manually The results from the Quicktrade Ultra Low II test kits were compared to those from the reference method to assess accuracy and linearity Multiple aliquots of performance test samples drinking water

4

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

samples and surface water samples were analyzed to assess precision Multiple aliquots of a low-level performance test sample were analyzed to assess the detection limit of the method Potential matrix interference effects were assessed by challenging the test kit with performance test samples of known arsenic concentrations that contained both low levels and high levels of interfering substances

Identical sets of samples were analyzed independently by a technical and a non-technical operator The technical operator was a technician at Battelle with three years of field and laboratory experience and a BA degree The non-technical operator was a part-time temporary helper enrolled in undergraduate studies Because the reagents of the Quicktrade Ultra Low II test kits were consumed in use it was not feasible for the two operators to use the same kits however each operator used multiple kits in order to analyze all the samples and it is assumed that kit-to-kit variability was similar for both operators Results of all analyses were statistically compared to evaluate operator bias The technical operator analyzed all samples using two different Quicktrade Arsenic Scan units and two different Compu-Scan units to assess inter-unit reproducibility

The rate of false positive and false negative results were evaluated relative to the 10-ppb maximum contaminant level for arsenic in drinking water(4) Other factors that were qualitatively assessed during the test included time required for sample analysis ease of use and reliability

33 Test Samples

Three types of samples were analyzed in the verification test as shown in Table 3-1 quality control (QC) samples performance test (PT) samples and environmental water samples The QC and PT samples were prepared from National Institute of Standards and Technology (NIST) traceable standards purchased from a commercial supplier and subject only to dilution as appropriate Under the Safe Drinking Water Act the EPA lowered the maximum contaminant level for arsenic from 50 ppb to 10 ppb effective January 2001 public water systems must comply with this standard by June 2006(4) Therefore the QC sample concentrations targeted the 10 ppb arsenic level The PT samples ranged from 10 to 1000 of the 10 ppb level (ie from 1 ppb to 100 ppb) The environmental water samples were collected from various drinking water and surface freshwater sources

Each sample was assigned a unique sample identification number when prepared in the laboratory or collected in the field The PT and environmental samples were submitted blind to the technical and non-technical operators and were analyzed randomly to the degree possible

331 QC Samples

QC samples included laboratory reagent blank (RB) samples quality control samples (QCS) and laboratory-fortified matrix (LFM) samples (Table 3-1) The RB samples consisted of the same ASTM Type I water used to prepare all other samples and were subjected to the same handling

5

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 3-1 Test Samples for Verification of the Quicktrade Ultra Low II Test Kit

Type of Sample Sample Characteristics

Arsenic Concentration (a)

No of Replicates

Quality Control

Reagent Blank (RB)

Quality Control Sample (QCS)

~ 0 ppb

10 ppb

10 of all

10 of all

Laboratory Fortified Matrix (LFM) 10 ppb above native level

1 per site

Performance Test

Prepared arsenic solution

Prepared arsenic solution

1 ppb

3 ppb

4

4

Prepared arsenic solution 10 ppb 4

Prepared arsenic solution 30 ppb 4

Prepared arsenic solution 100 ppb 4

Prepared arsenic solution for detection limit determination 3 ppb 7

Prepared arsenic solution spiked with low levels of interfering substances 10 ppb 4

Prepared arsenic solution spiked spiked with high levels of interfering substances 10 ppb 4

Environmental Battelle drinking water lt05 ppb 4

Ayer untreated water 648 ppb 4

Ayer treated water 139 ppb 4

Falmouth Pond water lt05 ppb 4

Taunton River water 131 ppb 4 (a) Performance Test sample concentrations are target levels environmental sample concentrations are actual (average of four replicate measurements)

and analysis procedures as the other samples The RB samples were used to verify that no arsenic contamination was introduced during sample handling and analysis RB samples were analyzed at a frequency of 10

The QCS consisted of Milli-Q water spiked in the lab to a concentration of 10 ppb arsenic with a NIST-traceable standard QCS were used as calibration checks to verify that the Quicktrade Ultra Low II test kit was operating properly QCS were analyzed at the beginning and end of each testing period as well as after every tenth sample Because the test kit utilized a color chart that could not be calibrated no performance criteria were specified for the QCS

6

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

The LFM samples consisted of aliquots of environmental samples that were spiked in the field to increase the arsenic concentration by 10 ppb The spike solution used for the LFM samples was prepared in the laboratory and brought to the field site One LFM sample was prepared from each environmental sample

332 PT Samples

Three types of PT samples used in this verification test (Table 3-1) spiked samples ranging from 1 ppb to 100 ppb arsenic a low-level spiked sample for evaluation of the test kitrsquos detection limit and matrix interference samples that were spiked with potential interfering substances All PT samples were prepared in the laboratory using Milli-Q water and NIST-traceable standards

Five PT samples containing arsenic at concentrations from 1 ppb to 100 ppb were prepared to evaluate Quicktrade Ultra Low II test kit accuracy and linearity Four aliquots of each of these samples were analyzed to assess precision

To determine the detection limit of the Quicktrade Ultra Low II test kit a PT sample was prepared with an arsenic concentration approximately five times the manufacturerrsquos estimated detection level Seven non-consecutive replicates of this 3 ppb arsenic sample were analyzed to provide precision data with which to estimate the method detection limit (MDL)

The matrix interference samples were spiked with 10 ppb arsenic as well as potentially interfering substances commonly found in natural water samples One sample contained low levels of interfering substances that consisted of 1 ppm iron 3 ppm sodium chloride and 01 ppm sulfide The second sample contained high levels of interfering compounds at the following concentrations 10 ppm iron 30 ppm sodium chloride and 10 ppm sulfide Four replicates of each of these samples were analyzed

333 Environmental Samples

The environmental samples listed in Table 3-1 included three drinking water samples and two surface water samples All environmental samples were collected in 20-L high density polyethylene (HDPE) carboys The Battelle drinking water sample was collected directly from a tap without purging Untreated and treated groundwater samples from the Ayer Massachusetts Department of Public Works Water Treatment Plant were collected directly from spigots also without purging Four aliquots of each sample were analyzed using the Quicktrade Ultra Low II test kit in the Battelle laboratory as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

One surface water sample was collected from a pond in Falmouth Massachusetts and another was collected from the Taunton River near Bridgewater Massachusetts These samples were collected near the shoreline by submerging a 2-L HDPE sample container no more than one inch below the surface of the water and decanting the water into a 20-L HDPE carboy until full Each water body was sampled at one accessible location These samples could not be analyzed at the field location as planned because of persistent severe winter weather conditions Therefore the samples were returned to a storage shed at the Battelle laboratory which was heated but not

7

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

serviced by running water The storage shed was intended to simulate realistic field conditions under which the test kits might be used Four aliquots of each surface water sample were analyzed in the storage shed as soon as possible after collection One aliquot of each sample was preserved with nitric acid and submitted to the reference laboratory for reference analysis

34 Reference Analysis

The reference arsenic analyses were performed in a Battelle laboratory using a Perkin Elmer Sciex Elan 6000 ICPMS according to EPA Method 2008 Revision 55(2) The sample was introduced through a peristaltic pump by pneumatic nebulization into a radiofrequency plasma where energy transfer processes caused desolvation atomization and ionization The ions were extracted from the plasma through a pumped vacuum interface and separated on the basis of their mass-to-charge ratio by a quadrupole mass spectrometer The ions transmitted through the quadrupole were registered by a continuous dynode electron multiplier and the ion information was processed by a data handling system

The ICPMS was tuned optimized and calibrated daily The calibration was performed using a minimum of five calibration standards at concentrations ranging between 05 and 250 ppb and a required correlation coefficient of a minimum of 0999 Internal standards were used to correct for instrument drift and physical interferences These standards were introduced in line through the peristaltic pump and analyzed with all blanks standards and samples

35 Verification Schedule

The verification test took place from January 29 through February 24 2003 Table 3-2 shows the daily activities that were conducted during this period The reference analyses were performed on March 7 and March 14 2003 five to six weeks after sample collection

8

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 3-2 Schedule of Verification Test Days

Sample Sample Analysis Date Collection Tech Non-tech Testing

Date Op Op Location Activity

12903- 12903- 12903- Battelle 21003 21003 21003 Laboratory

21203 21403 21403 Battelle Laboratory

21703 21803 21703 Battelle Laboratory

22103 22103 22103 Battelle Storage Shed

22303 22403 22403 Battelle Storage Shed

Preparation and analysis of PT and associated QC samples

Collection and analysis of Ayer untreated and treated water and associated QC samples

Collection and analysis of Battelle drinking water and associated QC samples

Collection and analysis of Falmouth Pond water and associated QC samples

Collection and analysis of Taunton River water and associated QC samples

9

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 4 Quality AssuranceQuality Control

Quality assurancequality control (QAQC) procedures were performed in accordance with the quality management plan (QMP) for the AMS Center(3) and the testQA plan for this verification test(1) QAQC procedures and results are described below

41 Laboratory QC for Reference Method

Reference analyses were conducted on March 7 and March 14 2003 Laboratory QC for the reference method included the analysis of RB QCS LFM and analytical duplicate samples Laboratory RB samples were analyzed to ensure that no contamination was introduced by the sample preparation and analysis process The testQA plan stated that if arsenic was detected in a RB sample above the MDL for the reference instrument then the contamination source would be identified and removed and proper blank readings achieved before proceeding with the reference analyses All of the laboratory RB samples analyzed were below the reporting limit for arsenic (ie below the concentration of the lowest calibration standard) except for several blanks that were analyzed at the end of the day on March 7 Three of the six test samples that were associated with these RB samples were re-analyzed on March 14 with acceptable RB sample results The other three test samples had arsenic concentrations that were approximately twenty times higher than the RB sample concentrations therefore no action was taken

On March 7 the instrument used for the reference method was calibrated using nine calibration standards with concentrations ranging from 05 to 250 ppb arsenic On March 14 it was calibrated using eight standards ranging in concentration from 01 to 25 ppb arsenic for more accurate analysis of low level samples The accuracy of the calibration was verified after the analysis of every ten samples by analyzing a QCS of a known concentration The percent recovery of the QCS was calculated from the following equation

R Cs

100 (1) s

where Cs is the measured concentration of the QCS and s is the spike concentration If the QCS analysis differed by more than 10 from the true value of the standard the instrument was recalibrated before continuing the test As shown in Table 4-1 all QCS analyses were within the required range

10

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 4-1 Reference Method QCS Analysis Results

Measured Percent Sample ID Analysis Date (ppb) Actual (ppb) Recovery

CCV 25 372003 2496 2500 100 QCS 25 372003 2681 2500 107 CCV 25 372003 2450 2500 98 CCV 25 372003 2539 2500 102 CCV 25 372003 2573 2500 103 CCV 25 372003 2581 2500 103 CCV 25 372003 2564 2500 103 CCV 25 372003 2530 2500 101 CCV 25 372003 2490 2500 100 CCV 25 372003 2267 2500 91 QCS 25 3142003 2490 2500 100 CCV 25 3142003 274 250 110 QCS 25 3142003 270 250 108 CCV 25 3142003 258 250 103 CCV 25 3142003 265 250 106 CCV 25 3142003 266 250 106 CCV 25 3142003 261 250 104 CCV 25 3142003 260 250 104

LFM samples were analyzed to assess whether matrix effects influenced the reference method results The LFM percent recovery (R) was calculated from the following equation

C CsR 100 (2) s

where Cs is the measured concentration of the spiked sample C is the measured concentration of the unspiked sample and s is the spike concentration If the percent recovery of an LFM sample fell outside the range from 85 to 115 a matrix effect was suspected As shown in Table 4-2 all of the LFM sample results were within this range

Duplicate samples were analyzed to assess the precision of the reference analysis The relative percent difference (RPD) of the duplicate sample analysis was calculated from the following equation

RPD (C CD )

100 (3) (C CD ) 2

Where C is the concentration of the sample analysis and CD is the concentration of the duplicate sample analysis If the RPD was greater than 10 the instrument was recalibrated before

11

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 4-2 Reference Method LFM Sample Results

Amount Unspiked Spiked Spiked Percent

Sample ID Matrix Analysis Date (ppb) (ppb) (ppb) Recovery ASTM Type I

CAA-22 water 372003 1102 3720 2500 105 ASTM Type I

CAA-25 R4 water 372003 095 2276 2500 87 ASTM Type I

CAA-28 R2 water 372003 345 3064 2500 109 ASTM Type I

CAA-29 R4 water 372003 3498 6037 2500 102 CAA-37 R4 Drinking water 372003 052 2820 2500 111 CAA-41 R4 Drinking water 372003 124 2888 2500 111 CAA-48 Surface water 372003 1226 3940 2500 109 CAA-47 R4 Surface water 372003 107 2841 2500 109

ASTM Type I CAA-27 R1 water 3142003 256 473 250 87 CAA-37 R3 Drinking water 3142003 045 311 250 107 CAA-47 R1 Surface water 3142003 136 416 250 112 CAA-88 R3 Drinking water 3142003 043 316 250 109 CAA-88 R4 Drinking water 3142003 042 318 250 111

Table 4-3 Reference Method Duplicate Analysis Results

Sample Duplicate Relative Analysis Concentration Concentration Percent

Sample ID Date (ppb) (ppb) Difference CAA-4 372003 933 920 14 CAA-70 372003 1093 1082 10 CAA-26 R1 372003 114 113 14 CAA-28 R3 372003 349 345 11 CAA-31 R1 372003 11189 11220 03 CAA-38 372003 1196 1190 05 CAA-42 372003 1302 1306 03 CAA-48 372003 1226 1222 04 CAA-23 3142003 303 299 13 CAA-27 R2 3142003 264 261 09 CAA-37 R4 3142003 044 043 23 CAA-47 R2 3142003 131 132 02 CAA-88 R4 3142003 042 038 95

12

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

continuing the test As shown in Table 4-3 the RPDs for the duplicate analysis were all less than 10 The RPD for one duplicate pair was 95 however the reported concentrations were below the reporting limit for the reference method (ie below the concentration of the lowest calibration standard)

42 Audits

Three types of audits were performed during the verification test a performance evaluation (PE) audit of the reference method a technical systems audit of the verification test performance and a data quality audit Audit procedures are described further below

421 Performance Evaluation Audit

A PE audit was conducted to assess the quality of the reference measurements made in this verification test For the PE audit an independent NIST-traceable reference material was obtained from a different commercial supplier than the calibration standards and the standard used to prepare the PT and QCS samples Accuracy of the reference method was verified by comparing the arsenic concentration measured using the calibration standards to those obtained using the independently-certified PE standard Relative percent difference as calculated by Equation 3 was used to quantify the accuracy of the results Agreement of the standard within 10 was required for the measurements to be considered acceptable As shown in Table 4-4 the PE sample analysis was within the required range

Table 4-4 Reference Method PE Audit Results

Measured Arsenic Actual Arsenic

Date of Concentration Concentration Percent Sample ID Analysis (ppb) (ppb) Difference

PE-1 32403 963 100 4

422 Technical Systems Audit

An independent Battelle Quality staff conducted a technical systems audit (TSA) on February 6 to ensure that the verification test was being conducted in accordance with the testQA plan(1)

and the AMS Center QMP(3) A TSA of the reference method performance was conducted by the Battelle Quality Manager on March 5 2003 when the reference analyses were initiated As part of the TSA test procedures were compared to those specified in the testQA plan data acquisition and handling procedures were reviewed and the reference standards and method were reviewed Observations and findings from the TSA were documented and submitted to the Battelle Verification Test Coordinator for response None of the findings of the TSA required corrective action TSA records are permanently stored with the Battelle Quality Manager

13

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

423 Data Quality Audit

At least 10 of the data acquired during the verification test was audited The Battelle Quality Manager traced the data from the initial acquisition through reduction and statistical analysis to final reporting to ensure the integrity of the reported results All calculations performed on the data undergoing the audit were checked

43 QAQC Reporting

Each audit was documented in accordance with Sections 334 and 335 of the QMP for the ETV AMS Center(3) Once the audit reports were prepared the Battelle Verification Test Coordinator ensured that a response was provided for each adverse finding or potential problem and impleshymented any necessary follow-up corrective action The Battelle Quality Manager ensured that follow-up corrective action was taken The results of the TSA and the data quality audit were submitted to the EPA

44 Data Review

Records generated in the verification test received a one-over-one review before these records were used to calculate evaluate or report verification results Table 4-5 summarizes the types of data recorded and reviewed All data were recorded by Battelle staff Data were reviewed by a Battelle technical staff member involved in the verification test but not the staff member that originally generated the record The person performing the review added hisher initials and the date to a hard copy of the record being reviewed Review of some of the test data sheets occurred outside of the two week period specified in the testQA plan

14

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 4-5 Summary of Data Recording Process

Data to be Recorded Where Recorded How Often Recorded Disposition of

Data(a)

Dates times of test ETV field data Startend of test event Used to organizecheck test events sheets results manually

incorporated in data spreadsheets as necessary

Test parameters ETV field data When set or changed or as Used to organizecheck test (temperature analyte sheets needed to document test results manually interferant identities incorporated in data and all Quicktrade Ultra spreadsheets as necessary Low II test kit results for color chart Quicktrade Arsenic Scan and Compu-Scan

Reference method Laboratory record Throughout sample Transferred to spreadsheets sample analysis chain books data sheets handling and analysis of custody and results or data acquisition process

system as appropriate

(a) All activities subsequent to data recording were carried out by Battelle

15

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 5 Statistical Methods

The statistical methods used to evaluate the performance factors listed in Section 32 are presented in this chapter Qualitative observations were also used to evaluate verification test data

51 Accuracy

All samples were analyzed by both the Quicktrade Ultra Low II test kit and reference methods For each sample accuracy was expressed in terms of a relative bias (B) as calculated from the following equation

B d x100 (4)

CR

where d is the average difference between the reading from the Quicktrade Ultra Low II test kit and those from the reference method and CR is the average of the reference measurements An additional assessment of accuracy was conducted for the color chart results because of the semishyquantitative nature of the visual comparisons Each color in the chart represents a concentration range Performance was assessed by determining whether the result falls within the expected concentration range as measured by the reference analysis Overall agreement was assessed by calculating the percent of results that fell within the correct range calculated from the following equation

A Y 100 (5)

n

where A is the percent of measurements in agreement Y is the number of measurements within the expected color range and n is the total number of measurements Readings below the vendor-stated detection limit of the test kit (ie lt04 ppb) were judged to be in agreement with the reference result if the reference value was in the specified ldquoless thanrdquo range

16

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

52 Precision

When possible the standard deviation (S) of the results for the replicate samples was calculated and used as a measure of Quicktrade Ultra Low II test kit precision at each concentration Standard deviation was calculated from the following equation

1 1 n 2

S (Ck C) 2 (6)

n 1 k 1

where n is the number of replicate samples Ck is the concentration measured for the kth sample and C is the average concentration of the replicate samples Precision was reported in terms of the relative standard deviation (RSD) as follows

SRSD 100 (7) C

53 Linearity

Linearity was assessed by performing a linear regression of Quicktrade Ultra Low II test kit results against the reference results with linearity characterized by the slope intercept and correlation coefficient (R) Linearity was tested using the five PT samples over the range 1 to 100 ppb arsenic and the detection limit study sample Samples with results below the vendor-stated test kit detection limit were not included Color chart results Quicktrade Arsenic Scan and Compu-Scan results were plotted against the corresponding reference concentrations and separate regressions were performed

54 Method Detection Limit

The MDL for the Quicktrade Ultra Low II test kit was assessed using results from seven replicate analyses of a sample spiked with approximately 3 ppb arsenic The standard deviation of the seven replicate samples was calculated using Equation (6) The MDL was calculated using the following equation

MDL t S (8)

where t is the Studentrsquos t value for a 99 confidence level and S is the standard deviation of the seven replicate samples

17

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

55 Matrix Interference Effects

The potential effect of interfering substances on the sensitivity of the Quicktrade Ultra Low II test kit was evaluated by the calculating accuracy (expressed as bias) using Equation 4 These results were qualitatively compared with accuracy results for PT samples containing only arsenic to assess whether there was a positive or negative effect due to matrix interferences

56 Operator Bias

Potential operator bias for the Quicktrade Ultra Low II test kit was assessed by performing a linear regression of sample results above the detection limit generated by the technical and nonshytechnical operator Color chart Quicktrade Arsenic Scan and Compu-Scan results were evaluated The slope intercept and correlation coefficient were used to evaluate the degree of operator bias A paired t-test was also conducted to evaluate whether the two sets of sample results were significantly different at a 95 confidence level

57 Inter-Unit Reproducibility

Inter-unit reproducibility for the Quicktrade Arsenic Scan and the Compu-Scan devices was assessed by performing a linear regression of sample results generated by the two units used by the technical operator The slope intercept and correlation coefficient were used to evaluate the degree of inter-unit reproducibility A paired t-test was also conducted to evaluated whether the two sets of sample results were significantly different at a 95 confidence level

58 Rate of False PositivesFalse Negatives

The rates of false positives and false negatives produced by the Quicktrade II test kit were assessed relative to the 10-ppb target arsenic level A false positive result is defined as any result reported to be greater than the guidance level (10 ppb) and greater than 125 of the reference value when the reference value is less than or equal to the guidance level Similarly a false negative result is defined as any result reported below the guidance level and less than 75 of the reference value when the reference value is equal to or greater than the guidance level The rates of false positives and false negatives were expressed as a percentage of total samples analyzed for each type of sample

18

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 6 Test Results

The results of the verification test of the Quicktrade Ultra Low II test kits are presented in this section

61 QC Samples

As described in Section 331 the QC samples analyzed with the Quicktrade Ultra Low II test kit included RB QCS and LFM samples (these QC samples were different than those analyzed in conjunction with the reference method) The RB samples were analyzed at a frequency of 10 and results were used to verify that no arsenic contamination was introduced during sample handling and analysis QCS were analyzed at the beginning and end of each test period and after every tenth sample The QCS results were used to verify that the test kit was operating properly One LFM sample was prepared from each environmental sample to evaluate potential matrix interferences Acceptance criteria for test kit QC samples were not specified in the testQA plan because modifications to the technology would not be made during testing

RB sample results for the technical and non-technical operators are presented in Tables 6-1a and 6-1b respectively Unique sample identification codes were assigned to each container of ASTM Type I water that was used The RB samples were analyzed at the required frequency The technical and non-technical operators recorded all RB sample results as below the detection limit for the color chart and the Quicktrade Arsenic Scan The Compu-Scan units always returned a detected value for RB samples except for one sample analyzed by the non-technical operator Because all color chart and Quicktrade Arsenic Scan results for the RB samples were below detection it appeared that arsenic contamination resulting from sample handling and analysis had not occurred

QCS results for the technical and non-technical operators are presented in Tables 6-2a and 6-2b respectively The QCS were analyzed at the required frequency except on the first day of testing when the technical operator inadvertently omitted one of these samples The percent recovery of the QCS was calculated using Equation 1 (Section 41) The QCS percent recovery for the technical operator ranged from 40 to 140 for the color chart from 0 to 125 for the Quicktrade Arsenic Scan and from 15 to 265 for the Compu-Scan The QCS percent recovery for the non-technical operator ranged from 22 to 140 for the color chart from 10 to 103 for the Quicktrade Arsenic Scan and from 11 to 175 for the Compu-Scan On average QCS recoveries for the color chart and Compu-Scan were within approximately 20 of the true value

19

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

20

Tab

le 6

-1a

RB

Sam

ple

Res

ults

for

the

Tech

nica

l Ope

rato

r

Qui

cktrade

Qui

cktrade

Ars

enic

A

rsen

ic S

can

Com

pu-S

can

Com

pu-S

can

Col

or C

hart

Sc

an

1 2

1

2

Sa

mpl

e ID

R

eplic

ate

Ana

lysi

s Dat

e (p

pb)

(ppb

) (p

pb)

(ppb

) (p

pb)

CA

A-3

1

129

200

3 lt0

4

lt02

lt0

2

15

2 C

AA

-8

1 1

312

003

lt04

lt0

2

lt02

1

1 1

CA

A-1

0 1

23

2003

lt0

4

lt02

lt0

2

07

13

CA

A-1

3 1

25

2003

lt0

4

lt02

lt0

2

05

08

CA

A-4

9 1

27

2003

lt0

4

lt02

lt0

2

05

07

CA

A-5

1 1

210

200

3 lt0

4

lt02

lt0

2

04

04

CA

A-5

2 1

210

200

3 lt0

4

lt02

lt0

2

05

06

CA

A-5

4 1

214

200

3 lt0

4

lt02

lt0

2

05

1 C

AA

-55

1 2

142

003

lt04

lt0

2

lt02

0

9 1

5 C

AA

-56

1 2

182

003

lt04

lt0

2

lt02

0

6 0

3 C

AA

-58

1 2

212

003

lt04

lt0

2

lt02

0

5 1

CA

A-5

9 1

224

200

3 lt0

4

lt02

lt0

2

07

07

Tab

le 6

-1b

RB

Sam

ple

Res

ults

for

the

Non

-Tec

hnic

al O

pera

tor

Col

or C

hart

Q

uick

trade A

rsen

ic S

can

1

Com

pu-S

can

1

Sam

ple

ID

Rep

licat

e A

naly

sis D

ate

(ppb

) (p

pb)

(ppb

) C

AA

-5

1 1

302

003

lt04

lt0

2

02

CA

A-7

1

131

200

3 lt0

4

lt02

0

5 C

AA

-11

1 2

420

03

lt04

lt0

2

006

C

AA

-13

1 2

520

03

lt04

lt0

2

04

CA

A-4

9 1

27

2003

lt0

4

lt02

N

D (

CA

A-5

1 1

210

200

3 lt0

4

lt02

0

06

CA

A-5

2 1

210

200

3 lt0

4

lt02

0

6 C

AA

-54

1 2

142

003

lt04

lt0

2

03

CA

A-5

5 1

214

200

3 lt0

4

lt02

0

5 C

AA

-56

1 2

172

003

lt04

lt0

2

04

CA

A-5

8 1

221

200

3 lt0

4

lt02

0

6 C

AA

-59

1 2

242

003

lt04

lt0

2

09

(a) C

ompu

-Sca

n re

adin

g w

as 0

0

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-2a

QC

S R

esul

ts fo

r th

e Te

chni

cal O

pera

tor(a

)

21

Sam

ple

ID

Rep

licat

e A

naly

sis

Dat

e

Col

orC

hart

(ppb

)

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Com

pu-

Scan

1

(ppb

)

Com

pu-

Scan

2

(ppb

)

Am

ount

Sp

iked

(p

pb)

Perc

ent

Rec

over

yC

olor

Cha

rt

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

1

Perc

ent

Rec

over

yQ

uick

tradeA

rsen

ic

Scan

2

Perc

ent

Rec

over

yC

ompu

-Sc

an

1

Perc

ent

Rec

over

yC

ompu

-Sc

an

2 C

AA

-2

1 1

292

003

10 (c

) 11

5 (c

) 11

5 (c

) 9

5 (c

) 14

5 (c

) 10

0

100

11

5

115

95

145

CA

A-1

5 1

131

200

3 9

(c)

525

(c)

525

(c)

15 (c

) 21

(c)

100

90

53

53

150

21

0

CA

A-1

5 2

131

200

3 11

(c)

99

(c)

107

5 (c

) 11

5 (c

) 13

5 (c

) 10

0

110

99

108

11

5

135

CA

A-1

6 1

23

2003

11

(c)

95

(c)

95

(c)

75

(c)

10 (c

) 10

0

110

95

95

75

100

CA

A-1

6 2

23

2003

10

(c)

9 (c

) 8

5 (c

) 13

(c)

19 (c

) 10

0

100

90

85

13

0

190

CA

A-1

7 1

25

2003

9

(c)

615

(c)

69

(c)

105

(c)

15 (c

) 10

0

90

62

69

10

5

150

CA

A-1

7 2

25

2003

14

(c)

125

(c)

115

(c)

195

(c)

265

(c)

100

14

0

125

11

5

195

26

5

CA

A-1

7 3

27

2003

11

(c)

105

(c)

12 (c

) 14

5 (c

) 21

(c)

100

11

0

105

12

0

145

21

0

CA

A-1

7 4

27

2003

7

5 (c

) 5

25 (c

) 5

25 (c

) 5

5 (c

) 10

(c)

100

75

53

53

55

10

0

CA

A-1

9 1

210

200

3 14

(c)

12 (c

) 12

(c)

10 (c

) 15

(c)

100

14

0

120

12

0

100

15

0

CA

A-1

9 2

210

200

3 10

(c)

49

(c)

575

(c)

3 (c

) 5

(c)

100

10

0

49

58

30

50

CA

A-2

0 1

214

200

3 7

5 (c

) 2

35 (c

) 2

35 (c

) 3

(c)

45

(c)

100

75

24

24

30

45

CA

A-2

0 2

214

200

3 4

(c)

lt02

(c)

1 (c

) 3

(c)

3 (c

) 10

0

40

0

10

30

30

CA

A-2

1 1

218

200

3 6

(b)

44

(b)

44

(b)

34

(b)

6 (b

) 10

0

60

44

44

34

60

CA

A-2

1 2

218

200

3 4

4 (b

) 2

2 (b

) 2

2 (b

) 3

8 (b

) 6

(b)

100

44

22

22

38

60

CA

A-7

1 1

221

200

3 6

(c)

1 (c

) 1

(c)

15

(c)

2 (c

) 10

0

60

10

10

15

20

CA

A-7

1 2

221

200

3 5

(c)

2 (c

) 1

5 (c

) 3

5 (c

) 3

5 (c

) 10

0

50

20

15

35

35

CA

A-7

2 1

224

200

3 9

(c)

77

(c)

77

(c)

145

(c)

95

(c)

100

90

77

77

145

95

CA

A-7

2 2

224

200

3 14

(c)

115

(c)

105

(c)

13 (c

) 12

5 (c

) 10

0

140

11

5

105

13

0

125

(a

) = T

he te

chni

cal o

pera

tor i

nadv

erte

ntly

om

itted

one

of t

he Q

CS

sam

ples

on

the

first

day

of t

estin

g (1

29

03)

(b) =

dilu

ted

12

(c) =

dilu

ted

15

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-2b

QC

S R

esul

ts fo

r th

e N

on-T

echn

ical

Ope

rato

r

22

Perc

ent

Qui

cktrade

Rec

over

yPe

rcen

t A

rsen

ic

Com

pu-

Am

ount

Perc

ent

Qui

cktrade

Rec

over

yA

naly

sis

Col

or C

hart

Sc

an

1

Scan

1

Sp

iked

Rec

over

yA

rsen

ic

Com

pu-

Sam

ple

ID

Rep

licat

e D

ate

(ppb

) (p

pb)

(ppb

) (p

pb)

Col

or C

hart

Sc

an

1 Sc

an

1 C

AA

-4

1 1

302

003

11

88

8 10

0

110

88

80

C

AA

-4

2 1

302

003

11

88

66

100

11

0

88

66

CA

A-1

5 1

131

200

3 6

52

55

100

60

52

55

CA

A-1

5 2

131

200

3 6

88

6 10

0

60

88

60

C

AA

-16

1 2

420

03

6 5

72

100

60

50

72

CA

A-1

6 2

24

2003

6

52

54

100

60

52

54

CA

A-1

7 1

25

2003

9

72

10

100

90

72

10

0

CA

A-1

7 2

25

2003

11

(a)

825

(a)

175

(a)

100

11

0

83

17

5

CA

A-1

7 3

27

2003

9

(a)

46

(a)

35

(a)

100

90

46

35

CA

A-1

7 4

27

2003

9

(a)

825

(a)

105

(a)

100

90

83

10

5

CA

A-1

9 1

210

200

3 6

63

63

100

60

63

63

CA

A-1

9 2

210

200

3 11

(a)

615

(a)

55

(a)

100

11

0

62

55

CA

A-2

0 1

214

200

3 9

69

82

100

90

69

82

CA

A-2

0 2

214

200

3 11

(a)

65

(a)

17 (a

) 10

0

110

65

170

C

AA

-21

1 2

172

003

22

123

1

1 10

0

22

12

11

C

AA

-21

2 2

172

003

22

098

1

7 10

0

22

10

17

C

AA

-70

1 2

212

003

9 (a

) 6

5 (a

) 5

5 (a

) 10

0

90

65

55

C

AA

-70

2 2

212

003

9 (a

) 1

(a)

4 (a

) 10

0

90

10

40

C

AA

-72

1 2

242

003

11 (a

) 6

5 (a

) 10

5 (a

) 10

0

110

65

105

C

AA

-72

2 2

242

003

14

102

5 16

5

100

14

0

103

16

5

(a) =

dilu

ted

15

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

indicating that these methods were operating as expected The average recoveries measured by the Quicktrade Arsenic Scan were more than 30 lower than the true value which was lower than expected

The LFM sample results for the technical and non-technical operators are presented in Tables 6-3a and 6-3b The percent recovery associated with each LFM sample was calculated using Equation 2 (Section 41) No evidence of matrix interferences is clearly indicated by these results with the possible exception of the Falmouth Pond water LFM sample The low recoveries measured by both operators for this sample indicate that a matrix interference may be affecting the recovery of arsenic Consequently test kit results for this sample may be biased low

62 PT and Environmental Samples

Table 6-4 presents the sample results for the PT and environmental samples The table includes the Quicktrade Ultra Low II test kit results and the reference method results The Quicktrade Ultra Low II test kit results are shown for both the technical and non-technical operators the Quicktrade Arsenic Scan Units 1 and 2 and the Compu-Scan Units 1 and 2 Some Quicktrade Ultra Low II test kit results were below the detection limit and were assigned a value of lt04 ppb for the color chart and lt02 ppb for the Quicktrade Arsenic Scan The reporting limit for the reference analyses was 05 ppb which corresponds to the lowest calibration standard used Results for each performance factor are presented below

621 Accuracy

Table 6-5 presents the accuracy results for the Quicktrade Ultra Low II test kit expressed as percent bias as calculated by Equation 4 (Section 51) Percent bias was not calculated for results below the detection limit The four replicate analyses for each sample were averaged in the calculation of bias The relative bias for the color chart ranged from -78 to 18 for the techshynical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the nonshytechnical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The reference method results for the Falmouth Pond water sample were below the reporting limit therefore the apparent matrix effect observed in the Falmouth Pond water LFM sample could not be verified

Table 6-6 presents accuracy results for each PT and environmental replicate sample according to whether the color chart result agreed with the reference value for that sample Each color block on the color chart represents a range of concentrations The reference sample result was assigned to the correct corresponding color block A test kit result was considered to agree with the reference method result if it fell within the range of plus or minus one color block (ie the concentration range spanning three adjacent color blocks) If the color chart test result for a given sample was within this range then a ldquoYrdquo was reported in Table 6-6 If the color chart result was

23

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 6-3a LFM Sample Results for the Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 6 10 60 Quicktrade Arsenic Scan 1 lt02 34 10 34 Quicktrade Arsenic Scan 2 lt02 34 10 34 Compu-Scan 1 04 56 10 52 Compu-Scan 2 045 46 10 42 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 20 10 60Quicktrade Arsenic Scan 1 7 10 10 30Quicktrade Arsenic Scan 2 7 1175 10 49Compu-Scan 1 15 225 10 78Compu-Scan 2 18 20 10 18Reference 6482 6974 10 49Ayer treated water LFM Color Chart lt04 14 10 140 Quicktrade Arsenic Scan 1 lt02 1025 10 103 Quicktrade Arsenic Scan 2 lt02 11 10 110 Compu-Scan 1 03 115 10 112 Compu-Scan 2 05 185 10 180 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 3 10 30 Quicktrade Arsenic Scan 1 lt02 1 10 10 Quicktrade Arsenic Scan 2 lt02 15 10 15 Compu-Scan 1 06 3 10 24 Compu-Scan 2 06 35 10 29 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 85 10 85 Quicktrade Arsenic Scan 2 lt02 85 10 85 Compu-Scan 1 06 75 10 69 Compu-Scan 2 07 115 10 108 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

24

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 6-3b LFM Sample Results for the Non-Technical Operator

Amount Unspiked(a) Spiked spiked Percent

Description (ppb) (ppb) (ppb) Recovery Battelle drinking water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 13 10 13 Compu-Scan 1 05 12 10 7 Reference lt05 1196 10 120 Ayer untreated water LFM Color Chart 14 30 10 161 Quicktrade Arsenic Scan 1 16 lt02 10 -16 Compu-Scan 1 82 25 10 168 Reference 6482 6974 10 49 Ayer treated water LFM Color Chart lt04 22 10 22 Quicktrade Arsenic Scan 1 lt02 138 10 14 Compu-Scan 1 06 35 10 29 Reference 139 1302 10 116 Falmouth Pond water LFM Color Chart lt04 15 10 15 Quicktrade Arsenic Scan 1 lt02 058 10 6 Compu-Scan 1 06 09 10 3 Reference lt05 1150 10 115 Taunton River water LFM Color Chart lt04 11 10 110 Quicktrade Arsenic Scan 1 lt02 65 10 65 Compu-Scan 1 10 15 10 140 Reference 131 1226 10 109

(a) Average of four replicates Non-detects were assigned a value of zero

outside this range then an ldquoNrdquo was reported Overall agreement was determined by calculating the total percent of results in agreement for the technical and non-technical operators The total percent agreement using this method was 70 for the technical operator and 57 for the nonshytechnical operator

622 Precision

Precision results for the Quicktrade Ultra Low II test kit are presented in Table 6-7 The RSD was determined according to Equation 7 (Section 52) The RSD was not calculated if any of the results for a set of replicates were below the detection limit (ie lt04 ppb for the color chart or lt02 ppb for the Quicktrade Arsenic Scan) For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the

25

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 2

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-S

can

1(p

pb)

Tech

nica

lO

pera

tor

Com

pu-S

can

2(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Tec

hnic

alO

pera

tor

Qui

cktrade

Ars

enic

Sca

n 1

(p

pb)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sca

n 1

(ppb

) R

efer

ence

(p

pb)

PT -

1 pp

b A

s C

AA

-26

CA

A-2

6 C

AA

-26

CA

A-2

6

1 2 3 4

12

12

15

15

11

11

11

11

11

09 1 11

13

18

24

06

22

26

13

08

15

15

15

15

15 098

1

05

098

07

08

09

06

091

0

86

090

0

86

PT -

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

3 28

22 3

26

21

17

28

25

21

17

27

42

38

16

44

49

45

28 7

5 22

22 5

34

18

123

3

1

61

42

26

43

256

2

64

250

2

71

PT -

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

10 (b

)

11 (b

)

11 (b

)

10 (b

) 9

(b)

11

5 (b

)

13

(b)

10

3 (b

) 8

5 (b

)

11

(b)

12

(b)

9

5 (b

) 9

5 (b

)

11

(b)

11

5 (b

)

7

(b)

12

5 (b

)

17

(b)

15

(b)

15

(b)

9

9 9 9

69

171

9

8 7

9

61

79

77 7

909

8

95

883

8

99

PT -

30 p

pb A

s C

AA

-29

CA

A-2

9 C

AA

-29

CA

A-2

9

1 2 3 4

30 (b

)

30 (b

)

30 (b

)

30 (b

) 29

5 (b

)

29

5 (b

)

32

5 (b

)

27

5 (b

) 29

5 (b

)

25

(b)

31

5 (b

)

25

(b)

36

5 (b

)

39

(b)

36

(b)

34

(b)

58

(b)

48

(b)

60

(b)

48

5 (b

) 56

(d)

56

(d)

44

(d)

44

(d)

34 (d

)

33

(d)

24

6 (d

)

34

(d)

80 (d

)

80

(d)

26

(d)

48

(d)

339

6

343

9

345

1

349

8 PT

- 10

0 pp

b A

s C

AA

-31

CA

A-3

1 C

AA

-31

CA

A-3

1

1 2 3 4

100

(d)

100

(d)

120

(d)

100

(d)

80 (d

)

12

6 (d

)

11

2 (d

)

10

0 (d

) 80

(d)

94

(d)

10

4 (d

)

94

(d)

126

(d)

13

8 (d

)

13

6 (d

)

12

2 (d

) 23

0 (d

)

19

8 (d

)

22

0 (d

)

22

8 (d

) 12

0 (d

)

12

0 (d

)

80

(d)

80

(d)

74

(d)

66

(d)

80

(d)

10

4 (d

) 14

4 (d

)

13

0 (d

)

10

4 (d

)

90

(d)

11

189

115

57

11

465

113

83

Det

ectio

n lim

it C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

CA

A-2

3 C

AA

-23

1 2 3 4 5 6 7

28 4 3 28

18

12 3

198

3

05

27

23

105

0

58

27

21

31

282

2

4 1

15

07

26

3 49

46

26

19

07

36

4 54

53

33

19

13 4

06 1 28

28

28

28

28

02

02

11

22

198

2

1 1

9

02

05

42

18

46

31

19

303

26

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) PT

- 10

ppb

As +

low

le

vel

inte

rfere

nts

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

14 (b

)

11 (b

)

75

(b)

11 (b

) 11

5 (b

)

11

5 (b

)

5

8 (b

)

12

(b)

11 (b

)

11

5 (b

)

6

5 (b

)

12

(b)

17 (b

)

17

5 (b

)

15

(b)

19

5 (b

) 28

5 (b

)

29

(b)

17

(b)

29

(b)

11

(b)

11

(b)

11

(b)

11

(b)

115

(b)

6

9 (b

)

9

(b)

5

5 (b

)

18

5 (b

)

15

(b)

14

(b)

3

5 (b

)

990

PT -

10 p

pbA

s + h

igh

leve

l in

terfe

rent

s

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

14 (b

)

11 (b

)

125

(b)

12 (b

) 10

3 (b

)

8

5 (b

)

9

(b)

9

5 (b

)

10

5 (b

)

9

5 (b

)

10

3 (b

)

10

5 (b

) 19

5 (b

)

13

5 (b

)

19

5 (b

)

15

5 (b

) 28

5 (b

)

24

5 (b

)

27

(b)

19

5 (b

) 5

(b)

11

(b)

11

(b)

11

(b)

1 (b

)

10

25

(b)

6

9 (b

)

6

9 (b

) 3

(b)

4

5 (b

)

6

(b)

7

(b)

115

9

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

00

05

05

05

03

05

06

04

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

05

05

04

lt05

lt0

5

lt05

lt0

5

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

6 (a

) 3

4 (a

) 3

4 (a

) 5

6 (a

) 4

6 (a

) 2

2 1

3 1

2 11

96

Aye

run

treat

edw

ater

CA

A-3

9 C

AA

-39

CA

A-3

9 C

AA

-39

1 2 3 4

20 (c

)

12 (c

)

4 (c

)

20 (c

) 11

(c)

4

(c)

lt0

2 (c

)

13

(c)

105

(c)

4

7 (c

)

lt0

2 (c

)

12

3 (c

) 20

(c)

5

(c)

5

(c)

29

(c)

19 (c

)

8

(c)

6

(c)

40

(c)

12 (c

)

12

(c)

30

(f)

1

8 3

(c)

3

(c)

lt0

2 f

02

17

(c)

5

(c)

25

f

1

65

61

62

73

67

47

634

8 A

yer

untre

ated

wat

er L

FM

CA

A-4

0 1

20 (e

) 10

(e)

117

5 (e

) 22

5 (e

) 20

(e)

30 (f)

lt0

2 (f)

25

(f)

697

4

Aye

rtre

ated

wat

er

CA

A-4

1 C

AA

-41

CA

A-4

1 C

AA

-41

1 2 3 4

lt04

lt0

4

04

lt04

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

01

01

05

04

05

04

08

03

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

05

06

06

07

136

1

45

144

1

32

Aye

rtre

ated

wat

er L

FM

CA

A-4

2 1

14 (b

) 10

25

(b)

11 (b

) 11

5 (b

) 18

5 (b

) 2

2 1

38

35

130

2

27

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-4 Q

uick

trade U

ltra

Low

II T

est K

it an

d R

efer

ence

Sam

ple

Res

ults

(con

tinue

d)

28

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Tech

nica

lO

pera

tor

Col

orC

hart

(ppb

)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1(p

pb)

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2(p

pb)

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

(ppb

)

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt(p

pb)

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

(ppb

)

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1(p

pb)

Ref

eren

ce

(ppb

) Fa

lmou

thPo

nd w

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

08

05

06

05

08

04

08

05

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

04

07

06

07

lt05

lt0

5

lt05

lt0

5

Falm

outh

Pond

wat

er

LFM

C

AA

-46

1 3

(b)

1 (b

) 1

5 (b

) 3

(b)

35

(b)

15

058

0

9 11

50

Taun

ton

Riv

erw

ater

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

lt02

lt0

2

07

07

05

05

07

06

07

08

lt04

lt0

4

lt04

lt0

4

lt02

lt0

2

lt02

lt0

2

11

07

16

07

136

1

31

131

1

26

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 11

(b)

85

(b)

85

(b)

75

(b)

115

(b)

11 (b

) 6

5 (b

) 15

(b)

122

6

(a) =

12

dilu

tion

(b) =

15

dilu

tion

(c) =

11

0 di

lutio

n (d

) = 1

20

dilu

tion

(e) =

12

5 di

lutio

n (f)

= 1

50

dilu

tion

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-5 Q

uant

itativ

e E

valu

atio

n of

Acc

urac

y fo

r Q

uick

trade U

ltra

Low

II T

est K

its

29

Bia

s N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-D

escr

iptio

n C

hart

Sc

an

1 Sc

an

2 Sc

an

1 Sc

an

2 C

hart

Sc

an

1 Sc

an

1 Pe

rfor

man

ce T

est S

ampl

es1

ppb

As

18

-7

-12

33

51

31

-11

-3

5

3 pp

b A

s -2

4

-36

-3

8

-3

33

0

-34

19

10 p

pb A

s 17

22

14

9

66

0

16

-20

30

ppb

As

-13

-1

4

-19

6

56

45

-9

70

10

0 pp

b A

s -8

-8

-1

8

14

92

-12

-2

9

3

10 p

pb A

s + lo

w le

vel

inte

rfere

nts

10

3

4

74

161

11

-17

29

10 p

pb A

s + h

igh

leve

l in

terf

eren

ts

7

-20

-1

2

47

11

5

-18

-4

6

-56

E

nvir

onm

enta

l Sam

ples

Batte

lle d

rinki

ng w

ater

N

A

NA

N

A

NA

N

A

NA

N

A

NA

Ba

ttelle

drin

king

wat

er L

FM

-50

-7

2

-72

-5

3

-62

-8

2

-89

-9

0

Aye

r unt

reat

ed w

ater

-7

8

NA

N

A

-77

-7

2

-78

N

A

-87

A

yer u

ntre

ated

wat

er L

FM

-71

-8

6

-83

-6

8

-71

-5

7

NA

-6

4

Aye

r tre

ated

wat

er

NA

N

A

NA

-8

0

-64

N

A

NA

-5

7

Aye

r tre

ated

wat

er L

FM

8

-21

-1

5

-12

42

-83

-8

9

-73

Fa

lmou

th P

ond

wat

er

NA

N

A

NA

N

A

NA

N

A

NA

N

A

Falm

outh

Pon

d w

ater

LFM

-7

4

-91

-8

7

-74

-7

0

-87

-9

5

-92

Ta

unto

n R

iver

wat

er

NA

N

A

NA

-5

4

-47

N

A

NA

-2

2

Taun

ton

Riv

er w

ater

LFM

-1

0

-31

-3

1

-39

-6

-10

-4

7

22

Pe

rcen

t bia

s cal

cula

ted

acco

rdin

g to

Equ

atio

n 4

Sec

tion

51

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits

Within Within Range (YN)

Range (YN) Non-Technical Technical Operator Operator

Description Sample ID Replicate Color Chart Color Chart Performance Test Samples 1 ppb As CAA-26 1 Y Y

CAA-26 2 Y Y CAA-26 3 Y Y CAA-26 4 Y Y

3 ppb As CAA-28 1 Y Y CAA-28 2 Y N CAA-28 3 N N CAA-28 4 Y Y

10 ppb As CAA-1 1 Y Y CAA-1 2 Y Y CAA-1 3 Y Y CAA-1 4 Y Y

30 ppb As CAA-29 1 Y N CAA-29 2 Y N CAA-29 3 Y Y CAA-29 4 Y Y

100 ppb As CAA-31 1 Y Y CAA-31 2 Y Y CAA-31 3 Y N CAA-31 4 Y N

10 ppb As + CAA-33 1 Y Y low level CAA-33 2 Y Y interferents CAA-33 3 Y Y

CAA-33 4 Y Y 10 ppb As + CAA-35 1 Y N high level CAA-35 2 Y Y interferents CAA-35 3 Y Y

CAA-35 4 Y Y Environmental Samples Battelle drinking water CAA-37 1 Y Y

CAA-37 2 Y Y CAA-37 3 Y Y CAA-37 4 Y Y

Battelle drinking water LFM CAA-38 1 N N Ayer untreated water CAA-39 1 N N

CAA-39 2 N N CAA-39 3 N N CAA-39 4 N N

Ayer untreated water LFM CAA-40 1 N N

30

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 6-6 Qualitative Evaluation of Agreement for Quicktrade Ultra Low II Test Kits (continued)

Within Range Within Range (YN) (YN)

Technical Non-Technical Operator Operator Color

Description Sample ID Replicate Color Chart chart Ayer treated water CAA-41 1 N N

CAA-41 2 N N CAA-41 3 N N CAA-41 4 N N

Ayer treated water LFM CAA-42 1 Y N Falmouth Pond water CAA-43 1 Y Y

CAA-43 2 Y Y CAA-43 3 Y Y CAA-43 4 Y Y

Falmouth Pond water LFM CAA-46 1 N N Taunton River water CAA-47 1 N N

CAA-47 2 N N CAA-47 3 N N CAA-47 4 N N

Taunton River water LFM CAA-48 1 Y Y

Percent Agreement 70 57

Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan For the reference measurements RSDs were a maximum of 4

623 Linearity

The linearity of the Quicktrade Ultra Low II test kit readings was assessed by performing a linear regression of the test kit results against the reference method results for the five PT samples ranging from 1 ppb to 100 ppb arsenic In these regressions results reported as below detection limits by the Quicktrade Ultra Low II test kit were not used Figures 6-1 6-2 and 6-3 present the results of the linear regressions for the color chart Quicktrade Arsenic Scan and Compu-Scan results respectively The slope intercept and correlation coefficient for each regression equation are shown on the charts For the color chart and Quicktrade Arsenic Scan the results for the technical operator were more linear and more closely corresponded to the reference method than the results for the non-technical operator For the Compu-Scan the results for the technical operator were more linear than those for the non-technical operator and the results for Unit 1 for both operators corresponded more closely to reference than the results for Unit 2

31

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-7 P

reci

sion

Res

ults

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

32

RSD

N

on-

Tec

hnic

al

Tec

hnic

al

Non

-T

echn

ical

N

on-

Tec

hnic

al

Ope

rato

rO

pera

tor

Tec

hnic

al

Tec

hnic

al

Tec

hnic

al

Ope

rato

rT

echn

ical

O

pera

tor

Qui

cktrade

Qui

cktrade

Ope

rato

rO

pera

tor

Ope

rato

rQ

uick

tradeO

pera

tor

Col

orA

rsen

ic

Ars

enic

C

ompu

-C

ompu

-C

olor

Ars

enic

C

ompu

-R

efer

ence

Des

crip

tion

Cha

rt

Scan

1

Scan

2

Scan

1

Scan

2

Cha

rt

Scan

1

Scan

1

Met

hod

Perf

orm

ance

Tes

t Sam

ples

1

ppb

As

13

2

8

50

48

0

4

17

3

3 pp

b A

s 14

22

20

37

36

45

43

33

4

10

ppb

As

5

16

15

21

12

0

44

11

1

30 p

pb A

s 0

7

12

6

12

14

15

45

1

100

ppb

As

10

19

11

6

7

23

20

21

1

Env

iron

men

tal S

ampl

esBa

ttelle

drin

king

NA

w

ater

N

A

NA

N

A

50

29

NA

N

A

11

A

yer u

ntre

ated

wat

er

55

51

43

80

85

84

78

13

9

3

Aye

r tre

ated

wat

er

NA

N

A

NA

75

43

N

A

NA

14

4

Falm

outh

Pon

d w

ater

N

A

NA

N

A

24

33

NA

N

A

24

N

A

Taun

ton

Riv

er w

ater

N

A

NA

N

A

19

12

NA

N

A

42

3

N

A o

ne o

r mor

e re

plic

ates

bel

ow d

etec

tion

limit

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

140

140

120

100

80

y = 092x + 022 R = 09948

y = 087x + 445 R = 09498

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Linear (Non-technical Operator) 60

40Colo

r cha

rt co

ncen

trat

ion

(ppb

)

Technical Operator Non-technical Operator Linear (Technical Operator)

20

0

Figure 6-1 Linearity of Quicktrade Ultra Low II Color Chart Results

120

100

y = 091x + 004 R = 09830

y = 081x + 055 R = 09934

y = 070x + 251 R = 09700

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1 80

Qui

ck A

rsen

ic S

can

conc

entr

atio

n (p

pb)

Technical Operator Unit 2 Non-techncial operator Unit 1 Linear (Technical Operator Unit 1) Linear (Technical Operator Unit 2) 60

40

20

0

Linear (Non-techncial operator Unit 1)

Figure 6-2 Linearity of Quicktrade Ultra Low II Quicktrade Arsenic Scan Results

33

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Com

pu-S

can

conc

entra

tion

(ppb

)

250

200

150

100

50

0

y = 115x - 088 R = 09980

y = 193x - 382 R = 09946

y = 103x + 399 R = 09322

0 20 40 60 80 100 120 140

Reference concentration (ppb)

11 line

Technical Operator Unit 1

Technical Operator Unit 2

Non-technical Operator Unit 1

Linear (Technical Operator Unit 1)Linear (Technical Operator Unit 2)Linear (Non-technical Operator Unit 1)

Figure 6-3 Linearity of Quicktrade Ultra Low II Compu-Scan Results

624 Method Detection Limit

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb arsenic Table 6-8 provides the standard deviation for the seven replicate samples for the technical and non-technical operator on the color chart Quick trade Arsenic Scan and Compu-Scan results and the calculated MDLs

625 Matrix Interference Effects

Matrix interference effects were assessed by comparing the calculated bias for the samples containing low-level and high-level concentrations of interfering substances with the bias reported for the other PT samples containing arsenic only (Table 6-5) The biases for the samples with low and high concentrations of interfering substances were similar to those for the PT samples that contained arsenic only indicating no apparent effect due to the presence of the interferents The biases associated with the Compu-Scan Unit 2 results for the low and high interferent samples were 161 and 115 respectively however these high biases were not observed in the samples analyzed by the color chart Quicktrade Arsenic Scan or Compu-Scan Unit 1 results

34

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Table 6-8 Detection Limit Results for Quicktrade Ultra Low II Test Kit

Sample ID

Technical Operator

Color Chart (ppb)

Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Technical Operator Quicktrade Arsenic Scan 2 (ppb)

Technical Operator Compu-Scan 1 (ppb)

Technical Operator Compu-Scan 2 (ppb)

Non-Technical Operator

Color Chart (ppb)

Non-Technical Operator Quicktrade Arsenic Scan 1 (ppb)

Non-Technical Operator Compu-Scan 1 (ppb)

CAA-23 Rep 1 28 198 21 3 4 06 02 02 CAA-23 Rep 2 4 305 31 49 54 1 02 05 CAA-23 Rep 3 3 27 282 46 53 28 11 42 CAA-23 Rep 4 28 23 24 26 33 28 22 18 CAA-23 Rep 5 18 105 115 19 19 28 198 46 CAA-23 Rep 6 12 058 07 07 13 28 21 31 CAA-23 Rep 7 3 27 26 36 4 28 19 19 Standard Deviation 091 092 089 148 157 098 088 171

Method Detection Limit (ppb)

29 29 28 47 49 31 28 54

626 Operator Bias

Operator bias was evaluated by comparing the color chart Quicktrade Arsenic Scan Unit 1 and Compu-Scan Unit 1 results above the detection limit for all PT and environmental samples produced by the technical and non-technical operators (the non-technical operator did not use the Quicktrade Arsenic Scan Unit 2 or the Compu-Scan Unit 2) Linear regression results are shown in Figure 6-4 The regression results suggest that there is little difference in the color chart and Compu-Scan results for the technical and non-technical operator The Quicktrade Arsenic Scan results tended to be higher for the technical operator than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 signifishycance level for the color chart and Compu-Scan but they were significantly different for the Quicktrade Arsenic Scan

627 Inter-Unit Reproducibility

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator Only results above the detection limit were included in the analysis Linear regressions of the two sets of data are shown in Figure 6-5 The results for the Quicktrade Arsenic Scan closely corresponded indicating that the performance of the two units was very similar The Compu-Scan results indicated that Unit 2 tended to return higher readings than Unit 1 A paired t-test of the two sets of data indicated that the results were not significantly different at a 5 significance level for the Quicktrade Arsenic Scan but were significantly different for the Compu-Scan

35

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

y = 095x + 173 R = 09204

y = 076x + 073 R = 09435

y = 094x + 222 R = 09313

0

20

40

60

80

100

120

140

160

Non

-tech

nica

l Ope

rato

r

Color Chart Quick Arsenic Scan Unit 1 Compu-Scan Unit 1 Linear (Color Chart) Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Technical Operator

Figure 6-4 Comparison of Quicktrade Ultra Low II Test Results for Technical and Non-Technical Operators

y = 087x + 110 R = 09918

y = 166x - 199 R = 09912

0

50

100

150

200

250

Uni

t 2 Quick Arsenic Scan Unit 1

Compu-Scan Unit 1 Linear (Quick Arsenic Scan Unit 1) Linear (Compu-Scan Unit 1)

11 line

0 20 40 60 80 100 120 140 160 Unit 1

Figure 6-5 Comparison of Quicktrade Ultra Low II Test Results for Quicktrade Arsenic Scan and Compu-Scan Units

36

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

628 Rate of False PositivesFalse Negatives

Tables 6-9 and 6-10 show the data and results for the rates of false positives and false negatives respectively obtained from the Quicktrade Ultra Low II test kit All PT and environmental samples were included in this evaluation

As shown in Table 6-9 32 samples had an arsenic concentration below 10 ppb as measured by the reference analysis For these samples none of the test kit color chart results were gt10 ppb and greater than 125 of the reference measurement for the technical and non-technical operators yielding false positive rates of 0 The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1)

Twenty-one samples had arsenic concentrations above 10 ppb as measured by the reference analysis (Table 6-10) For these samples the test kit color chart results were lt10 ppb and less than 75 of the reference measurement for three samples for the technical operator and five samples for the non-technical operator yielding false negative rates of 14 and 24 respectshytively The rates of false negatives for the Quicktrade Arsenic Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the non-technical operator (unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (units 1 and 2) and 48 for the non-technical operator (unit 1)

63 Other Factors

During testing activities the technical and non-technical operators were instructed to keep a record of their comments on ease of use reliability portability and generation of waste materials This section summarizes these observations and other comments pertaining to any problems encountered during testing Cost information is also presented

631 Ease of Use

The technical and non-technical operator both reported that the Quicktrade Ultra Low II test kit was very easy to use The test kit instructions were clear and easy to follow Although the manushyfacturer provided instructions for diluting samples above the 4 ppb arsenic level the nonshytechnical operator sometimes had difficulty successfully performing dilutions and correctly converting the results to a final concentration The three scoops used to sequentially add reagents were color coordinated which facilitated the efficient operation of the test kit The sample bottles were relatively easy to handle although a relatively large sample volume was required for analysis (600 mL) Extra care had to be taken to ensure that the caps to the reaction vessels were completely dry before proceeding with further analyses Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the

37

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 1

ppb

As

CA

A-2

6 C

AA

-26

CA

A-2

6 C

AA

-26

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

3 pp

b A

s C

AA

-28

CA

A-2

8 C

AA

-28

CA

A-2

8

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s C

AA

-1

CA

A-1

C

AA

-1

CA

A-1

1 2 3 4

N N N N

N Y Y N

N N Y N

N N Y N

Y Y Y Y

N N N N

N Y N N

N N N N

Bat

telle

drin

king

wat

er

CA

A-3

7 C

AA

-37

CA

A-3

7 C

AA

-37

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Aye

r tre

ated

w

ater

C

AA

-41

CA

A-4

1 C

AA

-41

CA

A-4

1

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Falm

outh

Pon

dw

ater

C

AA

-43

CA

A-4

3 C

AA

-43

CA

A-4

3

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

38

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-9 R

ate

of F

alse

Pos

itive

s for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

(con

tinue

d)

Des

crip

tion

Sam

ple

ID

Rep

licat

e

False

Pos

itive

(YN

)

Tech

nica

lO

pera

tor

Col

or C

hart

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

1

Tech

nica

lO

pera

tor

Qui

cktrade

Ars

enic

Sc

an

2

Tech

nica

lO

pera

tor

Com

pu-

Scan

1

Tech

nica

lO

pera

tor

Com

pu-

Scan

2

Non

-Te

chni

cal

Ope

rato

rC

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

rQ

uick

tradeA

rsen

ic

Scan

1

Non

-Te

chni

cal

Ope

rato

rC

ompu

-Sc

an

1 Ta

unto

n R

iver

wat

er

CA

A-4

7 C

AA

-47

CA

A-4

7 C

AA

-47

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

10 p

pb A

s +

low

leve

l in

terfe

rent

s

CA

A-3

3 C

AA

-33

CA

A-3

3 C

AA

-33

1 2 3 4

N N N N

N N N N

N N N N

Y Y Y Y

Y Y Y Y

N N N N

N N N N

Y Y Y N

Tota

l num

ber o

f sam

ples

32

32

32

32

32

32

32

32

To

tal f

alse

pos

itive

s 0

2 1

5 8

0 1

3 Pe

rcen

t fal

se p

ositi

ve

0

6

3

16

25

0

3

9

39

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Tab

le 6

-10

Rat

e of

Fal

se N

egat

ives

for

Qui

cktrade

Ultr

a Lo

w II

Tes

t Kits

Des

crip

tion

Sam

ple

ID

Rep

licat

e

Fals

e N

egat

ive

(YN

)

Tech

nica

l O

pera

tor

Col

or C

hart

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n1

Tech

nica

l O

pera

tor

Qui

cktrade

Ars

enic

Sca

n2

Tech

nica

l O

pera

tor

Com

pu-S

can

1

Tech

nica

l O

pera

tor

Com

pu-S

can

2

Non

-Te

chni

cal

Ope

rato

r C

olor

Cha

rt

Non

-Te

chni

cal

Ope

rato

r Q

uick

tradeA

rsen

ic S

can

1

Non

-Te

chni

cal

Ope

rato

r C

ompu

-Sca

n1

30

ppb

As

CA

A-2

9 C

AA

-29

CA

A-2

9 C

AA

-29

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

100

ppb

As

CA

A-3

1 C

AA

-31

CA

A-3

1 C

AA

-31

1 2 3 4

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

N N N N

Bat

telle

drin

king

wat

er L

FM

CA

A-3

8 1

Y

Y

Y

Y

Y

Y

Y

Y

Aye

r unt

reat

edw

ater

C

AA

-39

CA

A-3

9 C

AA

-39

CA

A-3

9

1 2 3 4

N N Y N

N Y Y N

N Y Y N

N Y Y N

N Y Y N

N N N Y

Y Y Y Y

Y Y N Y

Aye

r unt

reat

edw

ater

LFM

C

AA

-40

1 N

N

N

N

N

N

Y

N

A

yer t

reat

edw

ater

LFM

C

AA

-42

1 N

N

N

N

N

Y

Y

Y

Fa

lmou

th P

ond

wat

er L

FM

CA

A-4

6 1

Y

Y

Y

Y

Y

Y

Y

Y

Taun

ton

Riv

erw

ater

LFM

C

AA

-48

1 N

Y

Y

Y

N

N

Y

N

10

ppb

As +

hi

gh le

vel

inte

rfer

ents

CA

A-3

5 C

AA

-35

CA

A-3

5 C

AA

-35

1 2 3 4

N N N N

N Y N N

N N N N

N N N N

N N N N

Y N N N

Y N Y Y

Y Y Y Y

Tota

l num

ber o

f sam

ples

21

21

21

21

21

21

21

21

To

tal n

umbe

r of f

alse

neg

ativ

es

3 6

5 5

4 5

12

10

Perc

ent o

f fal

se n

egat

ives

14

29

24

24

19

24

57

48

40

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The test kit materials were readily transported to the Battelle storage shed where the environmental samples were tested

632 Analysis Time

The average total analysis time for a sample was about fifteen minutes at a sample temperature of 24degC The manufacturer provided a modified protocol that specified increased reaction times for samples below 24degC Two samples could be run concurrently without any confusion

633 Reliability

The Quicktrade Ultra Low II test kits operated reliably throughout the period of the test

634 Waste Material

The waste generated by the Quicktrade Ultra Low II test kit was manageable The vendorrsquos instructions provide a warning that hydrogen and arsine are generated during the test and recommend that testing be conducted in a well-ventilated area away from open flames and other sources MSDSs should be reviewed before handling any chemicals Instructions for the disposal of residual materials were clear and complete The residual liquid in the reaction vessel was allowed to settle before disposal in order to let particulates accumulate on the bottom A dilute hydrochloric acid solution was used to clean the reaction vessel prior to subsequent analyses Disposal of this waste in an appropriate manner must be taken into consideration

635 Cost

The listed price for a Quicktrade Ultra Low II test kit with color chart for analysis of 25 samples is $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

41

Chapter 7 Performance Summary

The Quicktrade Ultra Low II test kit was verified by evaluating the following parameters

Accuracy Precision Linearity MDL Matrix interference effects Operator bias Inter-unit reprodicibility Rate of false positivesfalse negatives

The quantitative assessment of accuracy indicated that the relative bias for the color chart ranged from -78 to 18 for the technical operator and -87 to 45 for the non-technical operator The relative bias for the Quicktrade Arsenic Scan ranged from -91 to 22 for the technical operator and -95 to 16 for the non-technical operator The relative bias for the Compu-Scan ranged from -80 to 161 for the technical operator and -92 to 70 for the non-technical operator The overall agreement for the color chart results based on an assessment of whether the result was assigned to the correct color block indicated that the total percent agreement was 70 for the technical operator and 57 for the non-technical operator

Precision was assessed by analyzing four replicates of each sample For the technical operator RSDs ranged from 0 to 55 for the color chart 2 to 51 for the Quicktrade Arsenic Scan and 6 to 85 for the Compu-Scan For the non-technical operator RSDs ranged from 0 to 84 for the color chart 4 to 78 for the Quicktrade Arsenic Scan and from 11 to 139 for the Compu-Scan

The linearity of response was evaluated by plotting the test kit results against the reference analysis results for the PT samples The equations for the linear regressions that were performed to evaluate linearity are summarized in Table 7-1 The slope y-intercept and correlation coefficient corresponding to a linear response that exactly matched reference concentrations would be 1 0 and 1 respectively

The MDL was assessed by analyzing seven replicates of a sample spiked at approximately 3 ppb The MDLs calculated using the precision data from these replicates ranged from 29 ppb to 31 ppb for the color charts 28 ppb to 29 ppb for the Quicktrade Arsenic Scan and 47 ppb to 54 ppb for the Compu-Scan

42

Table 7-1 Summary of Linear Regression Equations for Test Kit and Reference Results

Correlation Coefficient

Description Slope Intercept (R) Color chart technical operator 092 022 09948 Color chart non-technical operator 087 445 09498 Quicktrade Arsenic Scan 1 technical operator 091 004 09830 Quicktrade Arsenic Scan 2 technical operator 081 055 09934 Quicktrade Arsenic Scan 1 non-technical operator 070 251 09700 Compu-Scan 1 technical operator 115 -088 09980 Compu-Scan 2 technical operator 193 -382 09946 Compu-Scan 1 non-technical operator 103 399 09322

Results for samples containing low and high levels of interfering substances indicated that low and high levels of interferents did appear to affect the detection of arsenic Biases for these samples were similar to those calculated for PT samples containing arsenic only

An evaluation of Quicktrade Ultra Low II test kit results for the technical and non-technical operators indicated no apparent difference in the color chart and Compu-Scan results Measurements for the Quicktrade Arsenic Scan done by the technical operator tended to be higher than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 significance level for the color chart and Compu-Scan but were significantly different for the Quicktrade Arsenic Scan

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator The results for the Quicktrade Arsenic Scan closely corresponded however the results for Compu-Scan Unit 2 tended to be higher than the results for Unit 1 Paired t-tests of the two sets of data indicated that the Quicktrade Arsenic Scan results were not significantly different at a 5 significance level The Compu-Scan results for the two systems were significantly different

A false positive was defined as a test kit result that was greater than 10 ppb and greater than 125 of the reference concentration when the reference concentration is less than or equal to 10 ppb The rates of false positives for the technical and non-technical operators using the color charts were 0 for both operators The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1) A false negative was defined as a test kit result that was equal to or below 10 ppb and less than 75 of the reference concentration when the reference concentration was greater than 10 ppb The false negative rates for the technical and non-technical operators using the color charts were 14 and 24 respectively The rates of false negatives for the Quicktrade Arsenic

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Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the nonshytechnical operator (Unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (Units 1 and 2) and 48 for the non-technical operator (Unit 1)

The Quicktrade Ultra Low II test kits were easy to use and readily transportable to the field The time to analyze one sample is approximately 15 minutes at a temperature range of 24degC to 30degC longer reaction times are required for samples below this range Two samples can be run conshycurrently without difficulty The sample bottles were relatively easy to handle Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The cost for a 25-sample test kit with color chart is listed as $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other according to the vendor The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

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Table 7-1 Summary of Linear Regression Equations for Test Kit and Reference Results

Correlation Coefficient

Description Slope Intercept (R) Color chart technical operator 092 022 09948 Color chart non-technical operator 087 445 09498 Quicktrade Arsenic Scan 1 technical operator 091 004 09830 Quicktrade Arsenic Scan 2 technical operator 081 055 09934 Quicktrade Arsenic Scan 1 non-technical operator 070 251 09700 Compu-Scan 1 technical operator 115 -088 09980 Compu-Scan 2 technical operator 193 -382 09946 Compu-Scan 1 non-technical operator 103 399 09322

Results for samples containing low and high levels of interfering substances indicated that low and high levels of interferents did appear to affect the detection of arsenic Biases for these samples were similar to those calculated for PT samples containing arsenic only

An evaluation of Quicktrade Ultra Low II test kit results for the technical and non-technical operators indicated no apparent difference in the color chart and Compu-Scan results Measurements for the Quicktrade Arsenic Scan done by the technical operator tended to be higher than for the non-technical operator A paired t-test of each data set indicated that the results were not significantly different at a 5 significance level for the color chart and Compu-Scan but were significantly different for the Quicktrade Arsenic Scan

Inter-unit reproducibility was evaluated by comparing the data for the two Quicktrade Arsenic Scan units and the two Compu-Scan systems used by the technical operator The results for the Quicktrade Arsenic Scan closely corresponded however the results for Compu-Scan Unit 2 tended to be higher than the results for Unit 1 Paired t-tests of the two sets of data indicated that the Quicktrade Arsenic Scan results were not significantly different at a 5 significance level The Compu-Scan results for the two systems were significantly different

A false positive was defined as a test kit result that was greater than 10 ppb and greater than 125 of the reference concentration when the reference concentration is less than or equal to 10 ppb The rates of false positives for the technical and non-technical operators using the color charts were 0 for both operators The rates of false positives for the Quicktrade Arsenic Scan units were 6 and 3 for the technical operator (Units 1 and 2 respectively) and 3 for the non-technical operator (Unit 1) The rates of false positives for the Compu-Scan units were 16 and 25 for the technical operator (Units 1 and 2) and 9 for the non-technical operator (Unit 1) A false negative was defined as a test kit result that was equal to or below 10 ppb and less than 75 of the reference concentration when the reference concentration was greater than 10 ppb The false negative rates for the technical and non-technical operators using the color charts were 14 and 24 respectively The rates of false negatives for the Quicktrade Arsenic

43

Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the nonshytechnical operator (Unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (Units 1 and 2) and 48 for the non-technical operator (Unit 1)

The Quicktrade Ultra Low II test kits were easy to use and readily transportable to the field The time to analyze one sample is approximately 15 minutes at a temperature range of 24degC to 30degC longer reaction times are required for samples below this range Two samples can be run conshycurrently without difficulty The sample bottles were relatively easy to handle Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The cost for a 25-sample test kit with color chart is listed as $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other according to the vendor The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

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Scan units were 29 and 24 for the technical operator (units 1 and 2) and 57 for the nonshytechnical operator (Unit 1) The rates of false negatives for the Compu-Scan units were 24 and 19 for the technical operator (Units 1 and 2) and 48 for the non-technical operator (Unit 1)

The Quicktrade Ultra Low II test kits were easy to use and readily transportable to the field The time to analyze one sample is approximately 15 minutes at a temperature range of 24degC to 30degC longer reaction times are required for samples below this range Two samples can be run conshycurrently without difficulty The sample bottles were relatively easy to handle Dilution of samples with arsenic concentrations exceeding the optimal detection range may be a source of error and reduce the accuracy and precision of the associated results because of the difficulty in performing accurate dilution in a field setting The cost for a 25-sample test kit with color chart is listed as $29999 Replacement reagents and supplies are not available kits are provided as a complete set because reagents test strips and color charts are made to perform optimally with each other according to the vendor The Quicktrade Arsenic Scan and Compu-Scan are available as options for an additional cost of $159999 each

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Chapter 8 References

1 TestQA Plan for Verification of Portable Analyzers Battelle Columbus Ohio Version 2 December 8 2000

2 US EPA Method 2008 Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma Mass Spectrometry Revision 55 October 1999

3 Quality Management Plan (QMP) for the ETV Advanced Monitoring Systems Pilot Version 4 US EPA Environmental Technology Verification Program Battelle Columbus Ohio December 2002

4 US Code of Federal Regulations Title 40 Part 136 Appendix B

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