final report on the proficiency test on the determination … chemistry and instrumentation...
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IAEA / AL / 150
Final Report on the Proficiency Test on the Determinationof Total Arsenic Concentration in Water
TC Project BGD/08/018Seibersdorf, February 2005
IAEA / AL / 150
Department of Nuclear Sciences and Applications
Physics, Chemistry and Instrumentation Laboratory
Chemistry Unit
Final Report
Proficiency Test on the Determination of Total Arsenic Concentration in Water
TC Project BGD/08/018
Abdulghani Shakhashiro, Alexander Trinkl, Matthias Rossbach, Thomas Benesch, Michael Campbell, Umberto Sansone, Karin Will, Renate Schorn, Andras Törvenyi
Seibersdorf, June 2005
CONTENTS
ABSTRACT............................................................................................................................... 1
1. INTRODUCTION ............................................................................................................ 3
2. PROFICIENCY TEST OBJECTIVES ............................................................................. 3
3. PREPARATION OF PT MATERIALS ........................................................................... 4
4. VERIFICATION OF TARGET VALUES....................................................................... 4
4.1. Graphite Furnace Atomic Absorption Spectrometry determination [6] ............. 4 4.2. Inductively Coupled Plasma Mass Spectrometry ( ICP-MS )
Determination [7] ............................................................................................... 5
5. DESCRIPTION OF THE PT MATERIAL SENT TO THE PARTICIPANTS............... 8
6. PARTICIPATING ANALYTICAL TECHNIQUES ....................................................... 9
7. DATA EVALUATION .................................................................................................... 9
7.1. Data evaluation criteria....................................................................................... 9 7.2. Data evaluation sorted by Sample number ....................................................... 11 7.3. Data evaluation sorted by laboratory code ....................................................... 18
8. CONCLUSIONS AND RECOMMENDATIONS ......................................................... 29
9. REFERENCES ............................................................................................................... 29
APPENDIX I. LIST OF PARTICIPATING INSTITUTES .................................................. 30
APPENDIX II. EXAMPLES OF FORMS AND CORRESPONDENCE............................... 32
1
passed64%
failed36%
passed
97%
failed
3%
passed61%
failed
39%
ABSTRACT
A proficiency test on the determination of arsenic in drinking water was organised within the frame of the TC project BGD/8/018 to evaluate the analytical performance of laboratories in Bangladesh. This report summarises the performance evaluation of the participating laboratories.
Analytical data evaluation showed that 61% of data obtained a “Passed” final score for both the accuracy and precision criteria applied to this exercise.
Accuracy criteria Precision criteria Final Score
2
3
1. INTRODUCTION
The IAEA is actively promoting the establishment of quality systems in Member State laboratories by providing Technical Support programmes in close cooperation with the Agency Laboratories in Seibersdorf. For many years, several regional TC projects to implement “Quality Assurance/Quality Control for Nuclear Analytical Techniques” have resulted in the establishment of quality systems compliant with ISO/IEC 17025: 1999 standard in several laboratories. This can be considered as an appreciable success, as the base of much economic, health care or environmental decision relies on analytical data, and as it is well known, a decision based on incorrect analytical results can be extremely costly and detrimental. Therefore, it is essential that correct and reliable analytical data are used to make adequate decisions.
Demonstration of high quality analytical results requires, amongst other measures, regular participation in proficiency tests. This requirement of the ISO/IEC 17025: 1999 standard (clause 5.9 b) [1] currently can only be achieved by regular participation in laboratory analytical performance exercises provided by competent institutions. Generally, participation is expensive and not always appropriate to the specific needs. Therefore, within the frame of the IAEA project BGD/8/018 Seibersdorf Agency’s Laboratory was requested to organise a proficiency test for the laboratories in Bangladesh who are involved in Arsenic analysis.
It is well known that arsenic occurs naturally in variable levels in drinking water. It also can be introduced into the environment by other means, including mining activities and wood treatment.
It is now generally agreed that the arsenic contamination of groundwater in Bangladesh is of geological origin [2]. The arsenic derives from the geological strata underlying Bangladesh and it is attracting much attention due to its detrimental effect on public health and fears of future adverse health effects as a result of accumulation of arsenic in the human body. [2]
According to a 1999 study by the USA National Academy of Sciences [3], arsenic in drinking water causes bladder, lung and skin cancer, and may cause kidney and liver cancer. The study also found that arsenic harms the central and peripheral nervous systems, as well as heart and blood vessels, and causes serious skin problems. It also may cause birth defects and reproductive problems.
The national standard for arsenic in drinking water in Bangladesh is set to 50 µg total As /L, same as the current USA standard. However, on January 22, 2001 the US Environmental Protection Agency [4] [5] has adopted a new standard, and public water systems must comply with the 10 µg total As /L standard beginning January 23, 2006.
2. PROFICIENCY TEST OBJECTIVES
¶ To evaluate the analytical performance of the participating laboratories from Bangladesh for the determination of the total arsenic concentration in water.
¶ To assist in finding the root cause of methodological problems leading to unsatisfactory analytical performance in certain laboratories.
¶ To identify the necessity for further actions to improve laboratories performance if needed.
4
¶ To provide general recommendations on the overall performance of participating laboratories.
3. PREPARATION OF PT MATERIALS
The proficiency test set consisted of 7 samples: one blank, 2 certified reference materials and 4 spiked drinking water samples.
The water used for this exercise was collected from laboratory tap water (underground origin) at Seibersdorf. A 25 litre container of hard PE was used to collect the water.
All of the plastic bottles and containers were acid washed prior to use and rinsed three times with distilled water then air-dried.
The blank and the spiked samples were acidified with nitric acid at 0.5 mol/L . To spike samples number 02, 04, 05 and 07 aqueous mono elemental Arsenic standard 1000 mg As/L was used with appropriate dilutions. The uncertainty associated with the dilution was estimated according to the Guide for Quantifying Measurement Uncertainty issued by EURACHEM/CITAC (2000). [8]
The sample numbers 02 and 05 were prepared in one batch, i.e., duplicate samples, in order to verify the repeatability of the method. In similar way, samples number 04 and 07 were prepared also in one batch to get identical and homogenous duplicate samples.
The bottles were cleaned with acidified water, labelled and then rinsed with small amount of the sample and filled up to 225-250 ml.
4. VERIFICATION OF TARGET VALUES
The target values are the gravimetrically prepared spike values diluted in a class A volumetric flask, which were checked by both inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry. The expanded uncertainty for each target value was calculated as
U = kuc , k=2
where k is the coverage factor and uc is the combined standard uncertainty calculated according to the Guide for Quantifying Measurement Uncertainty issued by EURACHEM/CITAC (2000). [8]. The value of uc is intended to represent, at the level of one standard deviation, the combined effect of uncertainty components associated with the material preparation namely: standard solution, weighing and volume uncertainties.
4.1. Graphite Furnace Atomic Absorption Spectrometry determination [6]
A Graphite Furnace AAS using Zeeman background correction, (Perkin-Elmer Analyst 800 AAS Instrument) was used for this analysis. The samples were diluted 1+9 with deionised water on a gravimetric basis in order to ensure that the As content was within the linear and working range of the technique. All solutions contained 0.5 % v/v HNO3 (Merck, Suprapur).
5
All volumetric plastic ware had been acid washed prior to use. Optimisation of the system followed the established method involving maximising the signal response for a single-element standard by establishing the pyrolysis temperature.
An aqueous single element standard 50 µg As.L-1 was prepared from a single element stock solution (1000 mg/L, Merck) in 0.5 % nitric acid. The following concentrations of working standards were prepared by the Autosampler of the AAS Instrument by serial dilution:
0; 10; 20; 30 and 50 µg As.L-1
Three measurements were performed on each calibration solution.
Quantification was achieved against the aqueous calibration.
The following parameters were used:
- The analytical wavelength for As: 193.7 nm. - Slit width: 0.7. - Read time 5.0 s. - Matrix modifier: Pd + Mg(NO3)2
A quality control material (NIST 1643e; Trace elements in water) was analysed in parallel with the test samples. To check the instrumental drift, an aqueous standard solution was measured after every 3 samples.
The reported uncertainties are estimated according to the Guide for Quantifying Measurement Uncertainty issued by EURACHEM/CITAC (2000). [8]
Table. 1 : GF-AAS results
Sample name Chemistry Unit codeAS concentration
mgȚL-1U (k-2) mgȚL-1
PT Sample, #01 CU040400100 0.30 0.60PT Sample, #02 CU040400200 19.8 1.1PT Sample, #04 CU040400300 198 5PT Sample, #05 CU040400400 20.0 1.1PT Sample, #07 CU040400500 196 5NIST SRM 1643e QC material 60.4 1.4
Certified conc. NIST 1643e 60.45 ± 0.72 ng/mL
4.2. Inductively Coupled Plasma Mass Spectrometry ( ICP-MS ) Determination [7]
Inductively Coupled Plasma-Source Mass Spectrometry with conventional pneumatic nebulisation (Perkin-Elmer Sciex Elan 6000 ICP-MS instrument) was used in the analysis of the PT samples.
In order to incorporate an internal standard conveniently, the samples were diluted 1+9 on a gravimetric basis prior to analysis.
6
In order to prepare the instrument the sample introduction system was cleaned in situ by aspirating 1% HNO3. The nickel sample cones were cleaned using Polaris (a proprietary stainless steel polish), rinsed in deionised water and then placed in an ultrasonic bath for a few minutes. The ICP torch, bayonet and spray chamber were cleaned by soaking them in nitric acid (10%) and the peristaltic pump tubing was replaced prior to analysis. Optimisation of the system followed the established method involving maximising signal response for a multi-element standard by establishing nebuliser, RF forward power, ion optic and spatial parameters. A full instrumental optimisation was performed immediately prior to this experiment.
Calibration of the instrument was achieved by preparing an arsenic stock solution at ~10 µg/mL in 2% v/v HNO3), from a suitable mono elemental standard (Merck Certipur, 1000 µg/mL) on a gravimetric basis. The sub-stock was further diluted (gravimetrically) to produce working standards at: 0, 5, 10, 20, and 50 µg As.L-1 (in 2% HNO3). All working standards contained the internal standard (Y) at 25 µg As.L-1. Five measurements were performed on each sample.
Table No. 2 : ICP-MS results
Sample name ChemistryUnit code
ICP-MSCode
AsConcentration
µg.L-1
U (k=2) µg.L-1
PT Sample, #01 CU040400100 As PT 1 0.28 0.015 PT Sample, #02 CU040400200 As PT 2 20.20 0.2 PT Sample, #04 CU040400300 As PT 3 200 1.4 PT Sample, #05 CU040400400 As PT 4 20.3 0.1 PT Sample, #07 CU040400500 As PT 5 200 1.0
7
As concentration in Samples 04 and 07
185
190
195
200
205
210
ICP-MS (04) ICP-MS (07) GF-AAS (04) GF-AAS (07)
Analytical Technique
As
Con
cent
ratio
n (µ
g/L)
Sample 01- Blank Analysis
0.13
0.18
0.23
0.28
0.33
0.38
0.43
ICP-MS GF-AAS
Analytical Technique
As
Con
cent
ratio
n µg
/L
Fig. 1
As concentration in Samples 02 and 05
18
19
20
21
22
23
ICP-MS (02) ICP-MS (05) GF-AAS (02) GF-AAS (05)
Analytical Technique
As C
once
ntra
tion
µg/L
Fig. 2
Fig. 3
8
The results of blank analysis, samples 02 and 05, 04 and 07 are shown in figures 1, 2 and 3 respectively. From these figures it can be concluded that the target values are in agreement with the measured values by 2 different analytical techniques: GF AAS and ICP-MS.
Table 3 target values and the associated uncertainties:
Sample name Description Target Value
As µg.L-1U (k=2)
PT Sample, #01 Blank 0.28 0.60 PT Sample, #02 Spiked sample 20.0 0.2 PT Sample, #03 SPS-SW-2 Reference Material 50.0 0.3 PT Sample, #04 Spiked sample 200.3 2.7 PT Sample, #05 Spiked sample 20.0 0.2 PT Sample, #06 SPS-SW-2 Reference Material 50.0 0.3 PT Sample, #07 Spiked sample 200.3 2.7
5. DESCRIPTION OF THE PT MATERIAL SENT TO THE PARTICIPANTS
Each participant received 7 samples and one bottle of 1000 mg/L of As standard solution. Each sample had its own code, which consisted of four digits, first two digits to code the sample type, and the third and fourth digits for laboratory coding. The description of these samples is shown in table 4:
# Sample code Description
VolumemL
1 01 Blank - tap water used for preparing the spiked PT samples 2502 02 Low level of As in spiked tap water 250 3 03 Reference material SPS-SW-2 100 4 04 Medium level of As in spiked tap water 250
5 05 Duplicate of Low level of As in spiked tap water, prepared in the same batch as sample 02. 250
6 06 Reference material SPS-SW-2 100 7 07 Medium level of As in spiked tap water 250
The participants were asked to perform 3 individual analysis of the 7 samples using different aliquots and to estimate the combined uncertainty of the whole analytical procedure according to EURACHEM Guide on Quantifying Uncertainty and Method validation in Analytical Measurements. Analysis results and estimated combined uncertainties had to be reported in the results and uncertainties reporting form (F-02) ( see Appendix B).
In addition, the participants received a standard solution 1000 As µg.L-1 to verify day-to-day calibration and to report any discrepancies between laboratory standard and the provided one.
In order to assess the analytical performance of the method, the participating laboratories were requested to provide information on the method validation parameters and the approach used in the laboratory for the evaluation of uncertainty components and to compile these
9
information in the Method Validation and Combined Uncertainty Estimation Form (F-03) ( see Appendix B).
Furthermore, the participating laboratories were asked to give a description of the method used and quality control procedure applied in the laboratory. This information was filled in the Method and Quality Control Procedure Description Form (F-04) ( see Appendix B).
6. PARTICIPATING ANALYTICAL TECHNIQUES
¶ Instrumental neutron activation analysis ¶ Hydride generation atomic absorption spectrometry ¶ UV-VIS¶ Total reflection X-ray fluorescence ¶ ICP – MS ¶ ASV - Anodic Stripping Voltammetry
7. DATA EVALUATION
7.1. Data evaluation criteria
The participants’ data were evaluated according to the following three criteria:
A) The relative bias between the Analyst’s value and the IAEA value expressed as a relative bias in percentage:
%100Re ³-
=IAEA
IAEALab
ValueValueValuebiaslative
B) The Z-Score value calculated according to the following equation:
Where the target values for the standard deviation (s) has been be assigned as the following:
s = 0. 2 * Value IAEA
C) The value of the U-test score to be calculated according to the following equation [9] :
22LabIAEA
LabIAEAtest
UncUnc
ValueValueU
+
-=
The calculated U-test value was compared with the critical values listed in the t-statistic tables to determine if the reported result differs significantly from the expected value at a given level of probability at 99%:
sIAEALab
ScoreValueValuez -
=
10
Condition Probability Status
u < 1.64 Greater than 0.1 The reported result does not differ significantly from the expected value
1.95 > u > 1.64
Between 0.1 and 0.05
The reported result probably does not differ significantly from the expected value
2.58 > u > 1.95
Between 0.05 and 0.01
It is not clear whether the reported result differs significantly from the expected value
3.29 > u > 2.58
Between 0.01 and 0.001
The reported result is probably significantly different from the expected value
u > 3.29 Less than 0.001 The reported result is significantly different from the expected value
For this proficiency test we have set the limiting value for the u-test parameter to 2.58 to determine if a result passes the test (U < 2.58).
Acceptance criteria:
The PT results were evaluated against the following acceptance criteria for accuracy and precision and assigned the status “passed” or “rejected” accordingly. A result must pass both criteria to be assigned the final status of “passed”.
1) Accuracy: result passes if:
21 AA ¢ and %301001¢X
ValueA
IAEA
Where
A1= AnalystIAEA ValueValue -
A2= 2258.2 AnalystIAEA UncUnc +³
2) Precision: the result passes if:
P= %10022
³öö÷
õææç
å+öö
÷
õææç
å
Analyst
Analyst
IAEA
IAEA
ValueUnc
ValueUnc
is less than, or equal to 20 % the estimated maximum acceptable reproducibility standard deviation expressed in percentage of the measurement value.
11
7.2.
D
ata
eval
uatio
n so
rted
by
Sam
ple
num
ber
12
Tar
get v
alue
:20
.0µg
/LU
ncer
tain
ty (k
=2):
0.2
µg/L
Lab
orat
orie
s Res
ults
Acc
epta
nce
crite
ria
Fina
lV
alue
Unc
.A
ccur
acy
Prec
isio
nSc
ore
µg/L
µg/L
%A
1A
2Sc
ore
PSc
ore
0201
<15
--
--
--
--
--
reje
cted
0202
20.1
50.
763.
8%0.
7%0.
040.
190.
152.
03pa
ssed
3.9%
pass
edpa
ssed
0203
29.1
01.
505.
2%45
.5%
2.28
6.01
9.10
3.90
faile
d5.
3%pa
ssed
reje
cted
0204
25.0
02.
008.
0%25
.0%
1.25
2.49
5.00
5.19
pass
ed8.
1%pa
ssed
pass
ed02
0721
.85
0.70
3.2%
9.3%
0.46
2.54
1.85
1.88
pass
ed3.
4%pa
ssed
pass
ed02
086.
000.
366.
0%-7
0.0%
-3.5
0-3
4.00
14.0
01.
06fa
iled
6.1%
pass
edre
ject
ed02
0916
.70
0.70
4.2%
-16.
5%-0
.83
-4.5
33.
301.
88fa
iled
4.3%
pass
edre
ject
ed02
1020
.99
1.05
5.0%
4.9%
0.25
0.93
0.99
2.76
pass
ed5.
1%pa
ssed
pass
ed02
1125
.33
4.00
15.8
%26
.7%
1.33
1.33
5.33
10.3
3pa
ssed
15.8
%pa
ssed
pass
ed02
1218
.30
1.20
6.6%
-8.5
%-0
.43
-1.4
01.
703.
14pa
ssed
6.6%
pass
edpa
ssed
Tabl
e le
gend
:
A1:
A2:
P:
-1.
01
Lab
. Cod
e
Dat
a E
valu
atio
n fo
r Sa
mpl
e N
o. 0
2
Bia
s(%
)Z-
Scor
eU
-Sco
reL
abor
ator
y/IA
EA
1.46
1.25
1.09
0.30
0.84
1.27
1.05
0.92
Sam
ple
02 R
esul
ts
5101520253035
0201
0202
0203
0204
0207
0208
0209
0210
0211
0212
Labo
rato
ry C
ode
As Concentration (µg/L)
Labo
rato
ryIA
EAVa
lue
Valu
e-
22
58.2La
bora
tory
IAEA
Unc
Unc
+³
%10
02
.
2
XVa
lue
Unc
Valu
eU
nc
Lab
Lab
IAEA
IAEA
öö ÷õææ çå
+öö ÷õ
ææ çå
13
Tar
get v
alue
:50
µg/L
Unc
erta
inty
(k=2
):0.
3µg
/LL
abor
ator
ies R
esul
tsA
ccep
tanc
e cr
iteri
aFi
nal
Lab
. Cod
eV
alue
Unc
.A
ccur
acy
Prec
isio
nSc
ore
µg/L
µg/L
%A
1A
2Sc
ore
PSc
ore
0301
77.0
012
.07
15.7
%54
.0%
2.70
2.24
27.0
031
.15
faile
d15
.7%
pass
edre
ject
ed03
0250
.57
1.07
2.1%
1.1%
0.06
0.51
0.57
2.87
pass
ed2.
2%pa
ssed
pass
ed03
0364
.20
2.70
4.2%
28.4
%1.
425.
2314
.20
7.01
faile
d4.
2%pa
ssed
reje
cted
0304
55.0
02.
003.
6%10
.0%
0.50
2.47
5.00
5.22
pass
ed3.
7%pa
ssed
pass
ed03
0754
.94
2.20
4.0%
9.9%
0.49
2.22
4.94
5.73
pass
ed4.
0%pa
ssed
pass
ed03
0811
.00
0.49
4.5%
-78.
0%-3
.90
-67.
8839
.00
1.48
faile
d4.
5%pa
ssed
reje
cted
0309
61.2
01.
001.
6%22
.4%
1.12
10.7
311
.20
2.69
faile
d1.
7%pa
ssed
reje
cted
0310
40.5
12.
025.
0%-1
9.0%
-0.9
5-4
.65
9.49
5.27
faile
d5.
0%pa
ssed
reje
cted
0311
57.3
37.
3012
.7%
14.7
%0.
731.
007.
3318
.85
pass
ed12
.7%
pass
edpa
ssed
0312
48.3
02.
304.
8%-3
.4%
-0.1
7-0
.73
1.70
5.98
pass
ed4.
8%pa
ssed
pass
ed
Tabl
e le
gend
:
A1:
A2:
P:
Bia
s(%
)Z-
Scor
eU
-Sco
reL
abor
ator
y/IA
EA
1.54
1.01
1.28
1.10
1.10
Dat
a E
valu
atio
n fo
r Sa
mpl
e N
o. 0
3
0.97
0.22
1.22
0.81
1.15
Sam
ple
03 R
esul
ts
20.0
0
30.0
0
40.0
0
50.0
0
60.0
0
70.0
0
80.0
0
0301
0302
0303
0304
0307
0308
0309
0310
0311
0312
Labo
rato
ry C
ode
As Concentration (µg/L)
Labo
rato
ryIA
EAVa
lue
Valu
e-
22
58.2La
bora
tory
IAEA
Unc
Unc
+³
%10
02
.
2
XVa
lue
Unc
Valu
eU
nc
Lab
Lab
IAEA
IAEA
öö ÷õææ çå
+öö ÷õ
ææ çå
14
Tar
get v
alue
:20
0.3
µg/L
Unc
erta
inty
(k=2
):2.
7µg
/LL
abor
ator
ies R
esul
tsA
ccep
tanc
e cr
iteri
aFi
nal
Lab
. Cod
eV
alue
Unc
.A
ccur
acy
Prec
isio
nSc
ore
µg/L
µg/L
%A
1A
2Sc
ore
PSc
ore
0401
196.
0022
.49
11.5
%-2
.1%
-0.1
1-0
.19
4.30
58.4
4pa
ssed
11.6
%pa
ssed
pass
ed04
0221
0.90
4.08
1.9%
5.3%
0.26
2.17
10.6
012
.62
pass
ed2.
4%pa
ssed
pass
ed04
0323
5.00
10.0
04.
3%17
.3%
0.87
3.35
34.7
026
.72
faile
d4.
5%pa
ssed
reje
cted
0404
198.
304.
002.
0%-1
.0%
-0.0
5-0
.41
2.00
12.4
5pa
ssed
2.4%
pass
edpa
ssed
0407
239.
186.
812.
8%19
.4%
0.97
5.31
38.8
818
.90
faile
d3.
2%pa
ssed
reje
cted
0408
14.0
00.
584.
1%-9
3.0%
-4.6
5-6
7.46
186.
307.
12fa
iled
4.4%
pass
edre
ject
ed04
0919
6.00
8.00
4.1%
-2.1
%-0
.11
-0.5
14.
3021
.78
pass
ed4.
3%pa
ssed
pass
ed04
1019
8.35
1.42
0.7%
-1.0
%-0
.05
-0.6
41.
957.
87pa
ssed
1.5%
pass
edpa
ssed
0411
134.
0012
.33
9.2%
-33.
1%-1
.66
-5.2
566
.30
32.5
7fa
iled
9.3%
pass
edre
ject
ed04
1218
9.30
4.30
2.3%
-5.5
%-0
.27
-2.1
711
.00
13.1
0pa
ssed
2.6%
pass
edpa
ssed
Tabl
e le
gend
:
A1:
A2:
P:
0.98
1.05
1.17
Dat
a E
valu
atio
n fo
r Sa
mpl
e N
o. 0
4
Bia
s(%
)Z-
Scor
eU
-Sco
reL
abor
ator
y/IA
EA
0.99
1.19
0.95
0.07
0.98
0.99
0.67
Sam
ple
04 R
esul
ts
140.
00
160.
00
180.
00
200.
00
220.
00
240.
00
260.
00
0401
0402
0403
0404
0407
0408
0409
0410
0411
0412
Labo
rato
ry C
ode
As Concentration (µg/L)
Labo
rato
ryIA
EAVa
lue
Valu
e-
22
58.2La
bora
tory
IAEA
Unc
Unc
+³
%10
02
.
2
XVa
lue
Unc
Valu
eU
nc
Lab
Lab
IAEA
IAEA
öö ÷õææ çå
+öö ÷õ
ææ çå
15
Tar
get v
alue
:20
.0µg
/LU
ncer
tain
ty (k
=2):
0.2
µg/L
Lab
orat
orie
s Res
ults
Acc
epta
nce
crite
ria
Fina
lL
ab. C
ode
Val
ueU
nc.
Acc
urac
yPr
ecis
ion
Scor
eµg
/Lµg
/L%
A1
A2
Scor
eP
Scor
e05
01<1
5-
--
--
--
--
-re
ject
ed05
0219
.65
1.05
5.3%
-1.8
%-0
.09
-0.3
30.
352.
76pa
ssed
5.4%
pass
edpa
ssed
0503
28.1
01.
706.
0%40
.5%
2.03
4.73
8.10
4.42
faile
d6.
1%pa
ssed
reje
cted
0504
23.3
01.
506.
4%16
.5%
0.83
2.18
3.30
3.90
pass
ed6.
5%pa
ssed
pass
ed05
0719
.78
0.89
4.5%
-1.1
%-0
.05
-0.2
40.
222.
35pa
ssed
4.6%
pass
edpa
ssed
0508
7.00
0.46
6.6%
-65.
0%-3
.25
-25.
9213
.00
1.29
faile
d6.
6%pa
ssed
reje
cted
0509
17.2
01.
106.
4%-1
4.0%
-0.7
0-2
.50
2.80
2.88
pass
ed6.
5%pa
ssed
pass
ed05
1019
.68
1.90
9.7%
-1.6
%-0
.08
-0.1
70.
324.
93pa
ssed
9.7%
pass
edpa
ssed
0511
17.3
34.
0023
.1%
-13.
4%-0
.67
-0.6
72.
6710
.33
pass
ed23
.1%
faile
dre
ject
ed05
1218
.70
1.50
8.0%
-6.5
%-0
.33
-0.8
61.
303.
90pa
ssed
8.1%
pass
edpa
ssed
Tabl
e le
gend
:
A1:
A2:
P:
-0.
981.
41
Dat
a E
valu
atio
n fo
r Sa
mpl
e N
o. 0
5
Bia
s(%
)Z-
Scor
eU
-Sco
reL
abor
ator
y/IA
EA
1.17
0.99
0.94
0.35
0.86
0.98
0.87
Sam
ple
05 R
esul
ts
5.00
0
10.0
00
15.0
00
20.0
00
25.0
00
30.0
00
35.0
00
0501
0502
0503
0504
0507
0508
0509
0510
0511
0512
Labo
rato
ry C
ode
As Concentration (µg/L)
Labo
rato
ryIA
EAVa
lue
Valu
e-
22
58.2La
bora
tory
IAEA
Unc
Unc
+³
%10
02
.
2
XVa
lue
Unc
Valu
eU
nc
Lab
Lab
IAEA
IAEA
öö ÷õææ çå
+öö ÷õ
ææ çå
16
Tar
get v
alue
:50
.0µg
/LU
ncer
tain
ty (k
=2):
0.3
µg/L
Lab
orat
orie
s Res
ults
Acc
epta
nce
crite
ria
Fina
lL
ab. C
ode
Val
ueU
nc.
Acc
urac
yPr
ecis
ion
Scor
eµg
/Lµg
/L%
A1
A2
Scor
eP
Scor
e06
0152
.82
11.8
422
.4%
5.6%
0.28
0.24
2.82
30.5
6pa
ssed
22.4
%fa
iled
reje
cted
0602
52.1
81.
673.
2%4.
4%0.
221.
282.
184.
38pa
ssed
3.3%
pass
edpa
ssed
0603
64.1
02.
604.
1%28
.2%
1.41
5.39
14.1
06.
75fa
iled
4.1%
pass
edre
ject
ed06
0448
.30
1.50
3.1%
-3.4
%-0
.17
-1.1
11.
703.
95pa
ssed
3.2%
pass
edpa
ssed
0607
50.0
01.
072.
1%0.
0%0.
000.
000.
002.
87pa
ssed
2.2%
pass
edpa
ssed
0608
9.00
0.85
9.4%
-82.
0%-4
.10
-45.
4941
.00
2.33
faile
d9.
5%pa
ssed
reje
cted
0609
53.1
03.
406.
4%6.
2%0.
310.
913.
108.
81pa
ssed
6.4%
pass
edpa
ssed
0610
40.7
20.
310.
8%-1
8.6%
-0.9
3-2
1.51
9.28
1.11
faile
d1.
0%pa
ssed
reje
cted
0611
28.3
34.
6616
.4%
-43.
3%-2
.17
-4.6
421
.67
12.0
5fa
iled
16.5
%pa
ssed
reje
cted
0612
48.3
00.
601.
2%-3
.4%
-0.1
7-2
.53
1.70
1.73
pass
ed1.
4%pa
ssed
pass
ed
Tabl
e le
gend
:
A1:
A2:
P:
1.06
1.04
1.28
Dat
a E
valu
atio
n fo
r Sa
mpl
e N
o. 0
6
Bia
s(%
)Z-
Scor
eU
-Sco
reL
abor
ator
y/IA
EA
0.97
1.00
0.97
0.18
1.06
0.81
0.57
Sam
ple
06 R
esul
ts
20.0
0
30.0
0
40.0
0
50.0
0
60.0
0
70.0
0
80.0
0
0601
0602
0603
0604
0607
0608
0609
0610
0611
0612
Labo
rato
ry C
ode
As Concentration (µg/L)
Labo
rato
ryIA
EAVa
lue
Valu
e-
22
58.2La
bora
tory
IAEA
Unc
Unc
+³
%10
02
.
2
XVa
lue
Unc
Valu
eU
nc
Lab
Lab
IAEA
IAEA
öö ÷õææ çå
+öö ÷õ
ææ çå
17
Tar
get v
alue
:20
0.3
µg/L
Unc
erta
inty
(k=2
):2.
7µg
/LL
abor
ator
ies R
esul
tsA
ccep
tanc
e cr
iteri
aFi
nal
Lab
. Cod
eV
alue
Unc
.A
ccur
acy
Prec
isio
nSc
ore
µg/L
µg/L
%A
1A
2Sc
ore
PSc
ore
0701
232.
0024
.98
10.8
%15
.8%
0.79
1.26
31.7
064
.82
pass
ed10
.9%
pass
edpa
ssed
0702
210.
933.
631.
7%5.
3%0.
272.
3510
.63
11.6
7pa
ssed
2.2%
pass
edpa
ssed
0703
229.
008.
003.
5%14
.3%
0.72
3.40
28.7
21.7
8fa
iled
3.7%
pass
edre
ject
ed07
0420
1.70
2.50
1.2%
0.7%
0.03
0.38
1.4
9.49
pass
ed1.
8%pa
ssed
pass
ed07
0723
8.19
11.8
05.
0%18
.9%
0.95
3.13
37.8
931
.23
faile
d5.
1%pa
ssed
reje
cted
0708
12.0
00.
584.
8%-9
4.0%
-4.7
0-6
8.19
188.
37.
12fa
iled
5.0%
pass
edre
ject
ed07
0920
0.00
6.00
3.0%
-0.1
%-0
.01
-0.0
50.
316
.98
pass
ed3.
3%pa
ssed
pass
ed07
1020
0.03
0.45
0.2%
-0.1
%-0
.01
-0.1
00.
277.
06pa
ssed
1.4%
pass
edpa
ssed
0711
141.
6612
.00
8.5%
-29.
3%-1
.46
-4.7
758
.631
.73
faile
d8.
6%pa
ssed
reje
cted
0712
183.
307.
203.
9%-8
.5%
-0.4
2-2
.21
17.0
019
.84
pass
ed4.
2%pa
ssed
pass
ed
Tabl
e le
gend
:
A1:
A2:
P:
1.16
1.05
1.14
Dat
a E
valu
atio
n fo
r Sa
mpl
e N
o. 0
7
Bia
s(%
)Z-
Scor
eU
-Sco
reL
abor
ator
y/IA
EA
1.01
1.19
0.92
0.06
1.00
1.00
0.71
Sam
ple
07 R
esul
ts
140.
00
160.
00
180.
00
200.
00
220.
00
240.
00
260.
00
0701
0702
0703
0704
0707
0708
0709
0710
0711
0712
Labo
rato
ry C
ode
As Concentration (µg/L)
Labo
rato
ryIA
EAVa
lue
Valu
e-
22
58.2La
bora
tory
IAEA
Unc
Unc
+³
%10
02
.
2
XVa
lue
Unc
Valu
eU
nc
Lab
Lab
IAEA
IAEA
öö ÷õææ çå
+öö ÷õ
ææ çå
18
7.3.
D
ata
eval
uatio
n so
rted
by
labo
rato
ry c
ode
19
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
01
IAE
AA
ccep
tanc
e cr
iteri
aSa
mpl
e C
ode
Val
ueU
nc.
Val
ueU
nc.
R. b
ias
Z-sc
ore
U-T
est
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%A
1A
2Sc
ore
PSc
ore
0101
0.3
0.6
<15
--
--
--
--
--
pass
ed02
0120
.00.
2<1
5-
--
--
--
--
-re
ject
ed03
0150
.00.
377
.00
12.0
715
.7%
54%
2.70
2.24
27.0
031
.15
pass
ed15
.7%
pass
edpa
ssed
0401
202.
32.
719
6.00
22.4
911
.5%
-3%
-0.1
6-0
.28
6.30
58.4
4pa
ssed
11.6
%pa
ssed
pass
ed05
0120
.00.
2<1
5-
--
--
--
--
-re
ject
ed06
0150
.00.
352
.82
11.8
422
.4%
6%0.
280.
242.
820
30.5
6pa
ssed
22.4
%fa
iled
reje
cted
0701
202.
32.
723
2.00
24.9
810
.8%
15%
0.73
1.18
29.7
0064
.82
pass
ed10
.8%
pass
edpa
ssed
MD
LrL
RL
RC
15µg
/L1.
45%
1.94
%N
R
Rec
omm
enda
tions
:1-
Sam
ple
201
repo
rted
<15
µg/
L, w
hile
it c
onta
ins 2
0 µg
/L, t
his m
eans
that
MD
L sh
ould
be
revi
sed,
or s
ampl
e in
take
to b
e in
crea
sed
if th
e te
chni
ques
allo
ws.
2- R
epor
ted
rL in
dica
tes o
nly
1.45
% o
f var
iatio
ns, w
hile
dup
licat
e sa
mpl
es o
f the
PT
gave
mor
e th
an 1
5% v
aria
tions
, met
hod
repr
oduc
ibili
ty n
eeds
to b
e im
prov
ed,
may
be
the
way
of a
ddin
g th
e in
tern
al st
anda
rd sh
ould
be
revi
ewed
.3-
If th
e la
bora
tory
is in
tere
sted
in im
prov
ing
and/
or m
aint
aini
ng th
e pe
rfor
man
ce o
f the
ana
lytic
al te
chni
que,
the
Che
mis
try
Uni
t at A
genc
y's L
abor
ator
ies
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
RN
ot re
port
ed
1.54
0.97
Lab
orat
ory
Lab
orat
ory/
IAE
A
- - -1.
06
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
1.15
20
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
02
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
020.
30.
6B
DL
0.70
--
--
--
--
-pa
ssed
0202
20.0
0.2
20.1
50.
763.
8%1%
0.04
0.19
0.15
2.03
pass
ed3.
9%pa
ssed
pass
ed03
0250
.00.
350
.57
1.07
2.1%
1%0.
060.
510.
572.
87pa
ssed
2.2%
pass
edpa
ssed
0402
202.
32.
721
0.90
4.08
1.9%
4%0.
211.
768.
6012
.62
pass
ed2.
4%pa
ssed
pass
ed05
0220
.00.
219
.65
1.05
5.3%
-2%
-0.0
9-0
.33
0.35
2.76
pass
ed5.
4%pa
ssed
pass
ed06
0250
.00.
352
.18
1.67
3.2%
4%0.
221.
282.
180
4.38
pass
ed3.
3%pa
ssed
pass
ed07
0220
2.3
2.7
210.
933.
631.
7%4%
0.21
1.91
8.63
011
.67
pass
ed2.
2%pa
ssed
pass
ed
MD
LrL
RL
RC
1.9
µg/L
0.36
µg/L
NR
99.5
0%at
25.
9 µg
/L
Rec
omm
enda
tions
:1-
Acc
ordi
ng to
the
avai
labl
e da
ta th
e an
alyt
ical
resu
lts o
f the
labo
rato
ry a
re m
eetin
g bo
th a
ccur
acy
and
prec
isio
n cr
iteri
a.2-
The
labo
rato
ry re
port
ed re
sult
for s
ampl
e 01
02 sh
ould
not
exp
ress
ed a
s BD
L, th
e la
bora
tory
shou
ld in
stea
d re
port
the
resu
lt as
< 1
.9, w
hich
is th
e M
DL.
3- In
ord
er to
mon
itor t
he st
atis
tical
con
trol
and
the
perf
orm
ance
of t
he m
etho
d, th
e la
bora
tory
shou
ld u
se c
ontr
ol c
hart
s by
plot
ting
the
cont
rol s
ampl
es re
sults
an
d ch
ecki
ng fo
r tre
nds a
nd a
ny p
ossi
ble
out o
f con
trol
situ
atio
ns to
app
ly p
reve
ntiv
e an
d m
ay b
e co
rrec
tive
actio
ns w
hen
need
ed.
4- If
the
labo
rato
ry is
inte
rest
ed in
impr
ovin
g an
d/or
mai
ntai
ning
the
perf
orm
ance
of t
he a
naly
tical
tech
niqu
e, th
e C
hem
istr
y U
nit a
t Age
ncy'
s Lab
orat
orie
s is
read
y to
ass
ist t
he la
bora
tory
. For
furt
her i
nfor
mat
ion
plea
se c
onta
ct th
e C
hem
istr
y U
nit a
t u.sa
nson
e@ia
ea.o
rgM
DL
Met
hod
Min
imum
Det
ectio
n Li
mit
rLRe
peat
abili
ty li
mit
RL
Repr
oduc
ibili
ty li
mit
RC
Reco
very
coe
ffici
ent
NR
Not
repo
rted
BD
LBe
low
det
ectio
n lim
it
-
Lab
orat
ory/
IAE
A
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
Lab
orat
ory
1.04
1.04
0.98
1.04
1.01
1.01
21
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
03
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
030.
30.
60.
640.
05-
--
--
--
--
pass
ed02
0320
.00.
229
.10
1.50
5.2%
46%
2.28
6.01
9.10
3.90
faile
d5.
3%pa
ssed
reje
cted
0303
50.0
0.3
64.2
02.
704.
2%28
%1.
425.
2314
.20
7.01
faile
d4.
2%pa
ssed
reje
cted
0403
202.
32.
723
5.00
10.0
04.
3%16
%0.
813.
1632
.70
26.7
2fa
iled
4.5%
pass
edre
ject
ed05
0320
.00.
228
.10
1.70
6.0%
41%
2.02
4.73
8.10
4.42
faile
d6.
1%pa
ssed
reje
cted
0603
50.0
0.3
64.1
02.
604.
1%28
%1.
415.
3914
.100
6.75
faile
d4.
1%pa
ssed
reje
cted
0703
202.
32.
722
9.00
8.00
3.5%
13%
0.66
3.16
26.7
0021
.78
faile
d3.
7%pa
ssed
reje
cted
MD
LrL
RL
RC
1.9
µg/L
0.36
µg/L
NR
99.5
0%at
25.
9 µg
/L
Rec
omm
enda
tions
:1-
Fro
m th
e PT
resu
lt it
appe
ars t
hat t
he te
chni
que
prec
isio
n is
satis
fact
ory,
but
ther
e is
a sy
stem
atic
pos
itive
bia
s,whi
ch is
mor
e vi
sibl
e at
low
er c
once
ntra
tions
.2-
Fro
m th
e re
port
ed Q
ualit
y co
ntro
l dat
a, it
is a
lrea
dy st
ated
that
a p
ositi
ve b
ias o
f up-
to 1
5% is
obs
erve
d, b
ut n
o co
rrec
tive
actio
n w
as ta
ken.
3- T
he ro
ot c
ause
of t
he b
ias s
houl
d be
invi
stig
ated
and
app
ropr
iate
cor
rect
ive
actio
ns sh
ould
be
take
n.4-
If th
e la
bora
tory
is in
tere
sted
in im
prov
ing
and/
or m
aint
aini
ng th
e pe
rfor
man
ce o
f the
ana
lytic
al te
chni
que,
the
Che
mis
try
Uni
t at A
genc
y's L
abor
ator
ies
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
5- M
etho
d va
lidat
ion
proc
edur
e sh
ould
be
appl
ied.
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
R N
ot re
port
ed
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
1.16
1.41
1.28
1.13
Lab
orat
ory
-1.
461.
28
Lab
orat
ory/
IAE
A
22
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
04
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
040.
30.
6B
DL
--
--
--
--
--
pass
ed02
0420
.00.
225
.00
2.00
8.0%
25%
1.25
2.49
5.00
5.19
pass
ed8.
1%pa
ssed
pass
ed03
0450
.00.
355
.00
2.00
3.6%
10%
0.50
2.47
5.00
5.22
pass
ed3.
7%pa
ssed
pass
ed04
0420
2.3
2.7
198.
304.
002.
0%-2
%-0
.10
-0.8
34.
0012
.45
pass
ed2.
4%pa
ssed
pass
ed05
0420
.00.
223
.30
1.50
6.4%
17%
0.82
2.18
3.30
3.90
pass
ed6.
5%pa
ssed
pass
ed06
0450
.00.
348
.30
1.50
3.1%
-3%
-0.1
7-1
.11
1.70
03.
95pa
ssed
3.2%
pass
edpa
ssed
0704
202.
32.
720
1.70
2.50
1.2%
0%-0
.01
-0.1
60.
600
9.49
pass
ed1.
8%pa
ssed
pass
ed
MD
LrL
RL
RC
NR
NR
NR
NR
Rec
omm
enda
tions
:1-
Acc
ordi
ng to
the
avai
labl
e da
ta th
e an
alyt
ical
resu
lts o
f the
labo
rato
ry a
re m
eetin
g bo
th a
ccur
acy
and
prec
isio
n cr
iteri
a.2-
The
labo
rato
ry re
port
ed re
sult
for s
ampl
e 01
04 sh
ould
not
exp
ress
ed a
s BD
L, th
e la
bora
tory
shou
ld in
stea
d re
port
the
resu
lt of
the
MD
L w
hich
cou
ld b
e es
timat
ed fr
om m
etho
d va
lidat
ion
proc
edur
e.3-
Alth
ough
the
met
hod
is p
erfo
rmin
g w
ell,
the
labo
rato
ry sh
ould
est
imat
e th
e qu
ality
par
amet
ers o
f the
met
hod
whe
n it
is u
nder
stat
istic
al c
ontr
olan
d th
en to
mon
itor t
hese
par
amet
ers b
y m
eans
of c
ontr
ol c
hart
s to
mai
ntai
n g
ood
perf
orm
ance
leve
l.4-
If th
e la
bora
tory
is in
tere
sted
in im
prov
ing
and/
or m
aint
aini
ng th
e pe
rfor
man
ce o
f the
ana
lytic
al te
chni
que,
the
Che
mis
try
Uni
t at A
genc
y's L
abor
ator
ies
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
R N
ot re
port
edB
DL
Belo
w d
etec
tion
limit
Lab
orat
ory
-1.
251.
10
Lab
orat
ory/
IAE
A
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
0.98
1.17
0.97
1.00
23
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
07
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
070.
30.
6<3
--
--
--
--
--
pass
ed02
0720
.00.
221
.85
0.70
3.2%
9%0.
462.
541.
851.
88pa
ssed
3.4%
pass
edpa
ssed
0307
50.0
0.3
54.9
52.
204.
0%10
%0.
492.
234.
955.
73pa
ssed
4.0%
pass
edpa
ssed
0407
202.
32.
723
9.18
6.80
2.8%
18%
0.91
5.04
36.8
818
.88
faile
d3.
1%pa
ssed
reje
cted
0507
20.0
0.2
19.7
80.
904.
6%-1
%-0
.05
-0.2
40.
222.
38pa
ssed
4.7%
pass
edpa
ssed
0607
50.0
0.3
50.0
00.
992.
0%0%
0.00
0.00
0.00
02.
67pa
ssed
2.1%
pass
edpa
ssed
0707
202.
32.
723
8.19
5.00
2.1%
18%
0.89
6.32
35.8
9014
.66
faile
d2.
5%pa
ssed
reje
cted
MD
LrL
RL
RC
N.R
N.R
N.R
N.R
Rec
omm
enda
tions
:1-
The
low
and
med
ium
con
cent
ratio
n sa
mpl
es w
ere
succ
essf
ully
ana
lyse
d, b
ut a
t hig
her l
evel
of A
s the
labo
rato
ry o
vere
stim
ated
the
valu
es. T
he sa
mpl
e di
lutio
n m
ay b
e th
e ca
use.
2- T
he la
bora
tory
repo
rted
a re
sult
for s
ampl
e 01
07 <
3, w
hile
the
labo
rato
ry d
id n
ot p
erfo
rm a
ny m
etho
d va
lidat
ion.
3- T
he la
bora
tory
shou
ld e
stim
ate
the
qual
ity p
aram
eter
s of t
he m
etho
d w
hen
it is
und
er st
atis
tical
con
trol
and
then
to m
onito
r the
se p
aram
eter
s by
mea
ns o
f con
trol
cha
rts t
o m
aint
ain
the
good
per
form
ance
.4-
If th
e la
bora
tory
is in
tere
sted
in im
prov
ing
and/
or m
aint
aini
ng th
e pe
rfor
man
ce o
f the
ana
lytic
al te
chni
que,
the
Che
mis
try
Uni
t at A
genc
y's L
abor
ator
ies
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
R N
ot re
port
ed
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
1.18
0.99
1.00
1.18
Lab
orat
ory
-1.
091.
10
Lab
orat
ory/
IAE
A
24
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
08
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
080.
30.
66.
000.
81-
--
--
--
--
reje
cted
0208
20.0
0.2
6.00
0.36
6.0%
-70%
-3.5
0-3
4.00
14.0
01.
06fa
iled
6.1%
pass
edre
ject
ed03
0850
.00.
311
.00
0.49
4.5%
-78%
-3.9
0-6
7.88
39.0
01.
48fa
iled
4.5%
pass
edre
ject
ed04
0820
2.3
2.7
14.0
00.
584.
1%-9
3%-4
.64
-68.
1918
8.30
7.12
faile
d4.
4%pa
ssed
reje
cted
0508
20.0
0.2
7.00
0.46
6.6%
-65%
-3.2
5-2
5.92
13.0
01.
29fa
iled
6.6%
pass
edre
ject
ed06
0850
.00.
39.
000.
859.
4%-8
2%-4
.10
-45.
4941
.000
2.33
faile
d9.
5%pa
ssed
reje
cted
0708
202.
32.
712
.00
0.58
4.8%
-94%
-4.6
9-6
8.91
190.
300
7.12
faile
d5.
0%pa
ssed
reje
cted
MD
LrL
RL
RC
30 µ
g/L
2%20
%N
.R
Rec
omm
enda
tions
:1-
The
tech
niqu
e is
not
func
tioni
ng a
t all,
it c
an n
ot d
iffre
ntia
te b
etw
een
the
blan
k an
d th
e hi
ghes
t con
cent
ratio
n. C
ompl
ete
revi
sion
of t
he m
thod
is n
eded
. 2-
Qua
lity
cont
rol s
ampl
es sh
ould
be
able
to d
etec
t suc
h sh
ortc
omin
gs, b
ut it
seem
s tha
t it f
aile
d, th
refo
re re
visi
on o
f QC
mec
hani
sm is
als
o re
com
men
ded.
3- If
the
labo
rato
ry is
inte
rest
ed in
impr
ovin
g an
d/or
mai
ntai
ning
the
perf
orm
ance
of t
he a
naly
tical
tech
niqu
e, th
e C
hem
istr
y U
nit a
t Age
ncy'
s Lab
orat
orie
s is
read
y to
ass
ist t
he la
bora
tory
. For
furt
her i
nfor
mat
ion
plea
se c
onta
ct th
e C
hem
istr
y U
nit a
t u.sa
nson
e@ia
ea.o
rg
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
RN
ot re
port
ed
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
0.07
0.35
0.18
0.06
Lab
orat
ory
-0.
300.
22
Lab
orat
ory/
IAE
A
25
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
09
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
090.
30.
6<1
--
--
--
--
--
pass
ed02
0920
.00.
216
.70
0.70
4.2%
-17%
-0.6
6-4
.53
3.30
1.88
faile
d4.
3%pa
ssed
reje
cted
0309
50.0
0.3
61.2
01.
001.
6%22
%1.
1210
.73
11.2
02.
69fa
iled
1.7%
pass
edre
ject
ed04
0920
2.3
2.7
196.
008.
004.
1%-3
%-0
.16
-0.7
56.
3021
.78
pass
ed4.
3%pa
ssed
pass
ed05
0920
.00.
217
.20
1.10
6.4%
-14%
-0.7
0-2
.50
2.80
2.88
pass
ed6.
5%pa
ssed
pass
ed06
0950
.00.
353
.10
3.40
6.4%
6%0.
310.
913.
100
8.81
pass
ed6.
4%pa
ssed
pass
ed07
0920
2.3
2.7
200.
006.
003.
0%-1
%-0
.06
-0.3
52.
300
16.9
8pa
ssed
3.3%
pass
edpa
ssed
MD
LrL
RL
RC
<1 µ
g/L
NR
NR
NR
Rec
omm
enda
tions
:1-
Rep
eata
bilit
y ha
s to
be im
prov
ed, s
ampl
es 0
309
and
0609
are
dup
licat
e, b
ut th
e te
chni
que
give
s a d
iffer
ence
of
16%
bet
wee
n th
ese
dupl
icat
es.
The
root
cau
se m
ust b
e in
vist
igat
ed a
nd c
orre
cted
.2-
If th
e la
bora
tory
is in
tere
sted
in im
prov
ing
and/
or m
aint
aini
ng th
e pe
rfor
man
ce o
f the
ana
lytic
al te
chni
que,
the
Che
mis
try
Uni
t at A
genc
y's L
abor
ator
ies
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
RN
ot re
port
ed
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
0.97
0.86
1.06
0.99
Lab
orat
ory
-0.
841.
22
Lab
orat
ory/
IAE
A
26
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
10
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
100.
30.
60
0.00
--
--
--
--
-pa
ssed
0210
20.0
0.2
20.9
91.
055.
0%5%
0.25
0.93
0.99
2.76
pass
ed5.
1%pa
ssed
pass
ed03
1050
.00.
340
.51
2.02
5.0%
-19%
-0.9
5-4
.65
9.49
5.27
faile
d5.
0%pa
ssed
reje
cted
0410
202.
32.
719
8.40
1.42
0.7%
-2%
-0.1
0-1
.28
3.90
7.87
pass
ed1.
5%pa
ssed
pass
ed05
1020
.00.
219
.68
1.90
9.7%
-2%
-0.0
8-0
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0.32
4.93
pass
ed9.
7%pa
ssed
pass
ed06
1050
.00.
340
.72
0.31
0.8%
-19%
-0.9
3-2
1.51
9.28
01.
11fa
iled
1.0%
pass
edre
ject
ed07
1020
2.3
2.7
200.
030.
450.
2%-1
%-0
.06
-0.8
32.
270
7.06
pass
ed1.
4%pa
ssed
pass
ed
MD
LrL
RL
RC
NR
NR
NR
NR
Rec
omm
enda
tions
:1-
Acc
ordi
ng to
the
avai
labl
e da
ta th
e m
etho
d pe
rfor
ms p
rope
rly,
but
for u
nkno
wn
reas
on a
bia
s of 2
0% o
ccur
red
in sa
mpl
es 0
310,
061
0.
The
root
cau
se sh
ould
be
invi
stig
ated
and
cor
rect
ed.
2- Z
ero
valu
e fo
r det
ectio
n lim
it is
not
acc
epta
ble,
whe
n th
e la
bora
tory
can
not
det
ect t
he a
naly
te a
s in
sam
ple
0110
, the
MD
L es
timat
ed b
y m
etho
d va
lidat
ion
shou
ld b
e re
port
ed.
3- If
the
labo
rato
ry is
inte
rest
ed in
impr
ovin
g an
d/or
mai
ntai
ning
the
perf
orm
ance
of t
he a
naly
tical
tech
niqu
e, th
e C
hem
istr
y U
nit a
t Age
ncy'
s Lab
orat
orie
s is
read
y to
ass
ist t
he la
bora
tory
. For
furt
her i
nfor
mat
ion
plea
se c
onta
ct th
e C
hem
istr
y U
nit a
t u.sa
nson
e@ia
ea.o
rg
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
RN
ot re
port
ed
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
0.98
0.98
0.81
0.99
Lab
orat
ory
-1.
050.
81
Lab
orat
ory/
IAE
A
27
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
11
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
110.
30.
60
2.66
--
--
--
--
-pa
ssed
0211
20.0
0.2
25.3
34.
0015
.8%
27%
1.33
1.33
5.33
10.3
3pa
ssed
16%
pass
edpa
ssed
0311
50.0
0.3
57.3
37.
3012
.7%
15%
0.73
1.00
7.33
18.8
5pa
ssed
13%
pass
edpa
ssed
0411
202.
32.
713
4.00
12.3
39.
2%-3
4%-1
.68
-5.4
168
.30
32.5
7fa
iled
9%pa
ssed
reje
cted
0511
20.0
0.2
17.3
34.
0023
.1%
-13%
-0.6
7-0
.67
2.67
10.3
3pa
ssed
23%
faile
dre
ject
ed06
1150
.00.
328
.33
4.66
16.4
%-4
3%-2
.17
-4.6
421
.670
12.0
5fa
iled
16%
pass
edre
ject
ed07
1120
2.3
2.7
141.
6612
.00
8.5%
-30%
-1.5
0-4
.93
60.6
4031
.73
faile
d9%
pass
edre
ject
ed
MD
LrL
RL
RC
5µg/
L20
µg/
LN
RN
R
Rec
omm
enda
tions
:1-
Rep
eata
bilit
y ha
s to
be im
prov
ed, s
ampl
es 0
311
and
0611
are
dup
licat
e, b
ut th
e te
chni
que
give
s a d
iffer
ence
of
50%
bet
wee
n th
ese
dupl
icat
es.
The
root
cau
se m
ust b
e in
vist
igat
ed a
nd c
orre
cted
.2-
Zer
o va
lue
for d
etec
tion
limit
is n
ot a
ccep
tabl
e, w
hen
the
labo
rato
ry c
an n
ot d
etec
t the
ana
lyte
as i
n sa
mpl
e 01
11 th
e M
DL
estim
ated
from
met
hod
valid
atio
n sh
ould
be
repo
rted
.3-
The
line
ar ra
nge
of th
e m
etho
d m
ust b
e ch
ecke
d, si
nce
the
met
hods
giv
es sy
stem
atic
low
val
ues f
or sa
mpl
es 0
411,
071
14-
If th
e la
bora
tory
is in
tere
sted
in im
prov
ing
and/
or m
aint
aini
ng th
e pe
rfor
man
ce o
f the
ana
lytic
al te
chni
que,
the
Che
mis
try
Uni
t at A
genc
y's L
abor
ator
ies
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
RN
ot re
port
ed
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
0.66
0.87
0.57
0.70
Lab
orat
ory
-1.
271.
15
Lab
orat
ory/
IAE
A
28
Ana
lytic
al P
erfo
rman
ce E
valu
atio
n of
Lab
orat
ory
12
IAE
A[u
< 2
.58]
Acc
epta
nce
crite
ria
Sam
ple
Cod
eV
alue
Unc
.V
alue
Unc
.R
. bia
sZ-
scor
eu-
stat
istic
Acc
urac
yPr
ecis
ion
Fina
l sco
reµg
/Lµg
/Lµg
/Lµg
/L%
%01
120.
30.
60.
300.
10-
--
--
--
--
pass
ed02
1220
.00.
218
.30
1.20
6.6%
-9%
-0.4
3-1
.40
1.70
3.14
pass
ed6.
6%pa
ssed
pass
ed03
1250
.00.
348
.30
2.30
4.8%
-3%
-0.1
7-0
.73
1.70
5.98
pass
ed4.
8%pa
ssed
pass
ed04
1220
2.3
2.7
189.
304.
302.
3%-6
%-0
.32
-2.5
613
.00
13.1
0pa
ssed
2.6%
pass
edpa
ssed
0512
20.0
0.2
18.7
01.
508.
0%-7
%-0
.32
-0.8
61.
303.
90pa
ssed
8.1%
pass
edpa
ssed
0612
50.0
0.3
48.3
00.
601.
2%-3
%-0
.17
-2.5
31.
700
1.73
pass
ed1.
4%pa
ssed
pass
ed07
1220
2.3
2.7
184.
307.
203.
9%-9
%-0
.44
-2.3
418
.000
19.8
4pa
ssed
4.1%
pass
edpa
ssed
MD
LrL
RL
RC
NR
NR
NR
NR
Rec
omm
enda
tions
:1-
The
met
hod
repe
atab
ility
is sa
tisfa
ctor
y, b
ut th
e re
sults
are
syst
emat
ical
ly b
iase
d at
aro
und
3-9
% b
elow
the
targ
et v
alue
. T
he ro
ot c
ause
mus
t be
invi
stig
ated
and
cor
rect
ed.
2- T
he M
DL
of th
e m
etho
d w
as n
ot re
port
ed a
s a re
sult
of m
etho
d va
lidat
ion
data
, but
the
met
hod
prov
es to
be
able
to d
etec
t acc
urat
ely
belo
w 1
µg/
L.3-
The
labo
rato
ry sh
ould
est
imat
e th
e qu
ality
par
amet
ers o
f the
met
hod
whe
n it
is u
nder
stat
istic
al c
ontr
olan
d th
en to
mon
itor t
hese
par
amet
ers b
y m
eans
of c
ontr
ol c
hart
s to
mai
ntai
n an
d de
mon
stra
te th
e pe
rfor
man
ce le
vel.
4- If
the
labo
rato
ry is
inte
rest
ed in
impr
ovin
g an
d/or
mai
ntai
ning
the
perf
orm
ance
of t
he a
naly
tical
tech
niqu
e, th
e C
hem
istr
y U
nit a
t Age
ncy'
s Lab
orat
orie
s
MD
LM
etho
d M
inim
um D
etec
tion
Lim
itrL
Repe
atab
ility
lim
itR
LRe
prod
ucib
ility
lim
itR
CRe
cove
ry c
oeffi
cien
tN
RN
ot re
port
ed
0.94
0.97
0.91
is re
ady
to a
ssis
t the
labo
rato
ry. F
or fu
rthe
r inf
orm
atio
n pl
ease
con
tact
the
Che
mis
try
Uni
t at u
.sans
one@
iaea
.org
.
Rep
orte
d M
etho
d V
alid
atio
n Pa
ram
eter
s
0.94
Lab
orat
ory
-0.
920.
97
Lab
orat
ory/
IAE
A
29
8. CONCLUSIONS AND RECOMMENDATIONS
¶ This exercise shows the importance of participation in proficiency tests to assure the quality of the analytical data, especially when the analyte is of a great effect on the health such as arsenic.
¶ The PT samples were sent to 14 laboratories, 10 of them reported the results. 65 % of the reported results passed the accuracy criteria and 100% passed the precision criteria, while 65% of the results obtained a “Passed” grade as a final score.
¶ It is recommended for all laboratories to apply the Eurachem guide on method validation to estimate the method performance characteristics and to use control charts to monitor the stability of their methods.
¶ Only one case showed that the method used needs a complete revision, while in others cases some corrective actions might improve the performance.
¶ The analytical performance of each laboratory was studied and appropriate recommendations were suggested.
¶ The results of this report will be discussed in a forthcoming meeting, where also a workshop on method validation and uncertainty estimation can be organised.
9. REFERENCES
[1] ISO/IEC 17025:1999, General Requirements for the Competence of Testing and Calibration Laboratories, ISO, Geneva.
[2] Contamination of water supplies by arsenic in Bangladesh, Press Release WHO/55 8 September 2000.
[3] Arsenic in Drinking Water, Committee on Toxicology, Board on Environmental Studies and Toxicology, National Research Council, National Academy Press, Washington, DC, 1999.
[4] US Environmental Protection Agency, 40 CFR Parts 9, 141, and 142 [5] US Environmental Protection Agency, Implementation Guidance for the Arsenic Rule -
Drinking Water Regulations for Arsenic and Clarifications to Compliance and New Source Contaminants Monitoring - (EPA-816-K-02-018)
[6] TOERVENYI, A., IAEA Chemistry Unit, PCI Seibersdorf Laboratories, Analysis report No. CU 2004-018, Determination of the arsenic concentration in water samples for an AQCS PT exercise, 2004-11-25.
[7] CAMPBELL, M., IAEA Chemistry Unit, PCI Seibersdorf Laboratories, Analysis report No. CU 2004-15, Determination of the arsenic concentration in water samples for an AQCS PT exercise, 2004-10-22.
[8] Quantifying uncertainties in analytical measurements, Eurachem/Citac Guide, 2000. [9] BROOKES, C.J., BETTELEY, I.G. and LOXTON, S.M.; Fundamentals of
Mathematics and Statistics, Wiley 1979
30
APPENDIX I. LIST OF PARTICIPATING INSTITUTES
Dr. Sayed Mohammad Hossain Reactor and Neutron Physics Division, Institute of Nuclear Science & Technology, Atomic Energy Research Establishment, Ganakbari, Savar Bangladesh
Tel: 880-2-7701829 (Off.) Fax: 880-2-8613051 E-mail: [email protected]
Prof. Dr. A. M. Shafiqul AlamDepartment Chemistry, University of Dhaka, Dhaka 1000. Bangladesh
Tel: 880-2-9661920-59 Ext. 4864 (Off.), 880-2-8629985 (Res.) Fax: 880-2-8615583, E-mail: [email protected]
Nuclear Chemistry Division, Institute of Nuclear Science & Technology, Atomic Energy Research Establishment, Ganakbari, Savar Bangladesh
Tel: 880-2-7702009 (Off.) Fax: 880-2-8613051 E-mail: [email protected]
Mr. Ahmed Ataul Muneem Geological Survey of Bangladesh, 153, Pioneer Road, Segunbagicha, Dhaka 1000 Bangladesh
Prof. Sk. Sekender Ali Department of Civil Engineering, Bangladesh University of Engineering & Technology, Dhaka 1000 Bangladesh
Tel: 880-2-9665639, 880-2-9665650-80 Ext. 7284 Fax: 880-2-8613026
SMA Rashid Executive DirectorNGO FORUM for Drinking Water Supply & Sanitation 4/6, Block – E , Lalmatia Dhaka – 1207 Bangladesh
Tel: 880-2-8154273, 880-2-8154274, Fax: 880-2-8117924, E-mail: [email protected]
Dr. Quazi Quamruzzaman, G. Mohiuddin Dhaka Community Hospital, 190/1, Bara Mogbazar, Wirless Rail Gate, Dhaka 1217 Bangladesh
Tel: 9351190-1 Fax: 8313385 E-mail: [email protected]
31
Dr. A. K.M. Munir Sono Diagnostic Centre Ltd. Dept. of Environment Initiative, College More, Courtpara, Kushtia, Bangladesh
Tel: 071-61335 Fax: 071-61235 E-mail: [email protected]
Mr. Siddique Amin Talukder Department of Public Health Engineering, Zonal Laboratory, Rajshahi
Dr. Muhammad Alauddin Exonics Technology Centre (ETC) House # 10, Road # 06, Sector 1, Uttara, Dhaka Bangladesh
Tel: 0173002632, 0171197979, 0172084444 E-mail: [email protected]
Chemistry Division, Atomic Energy Centre, 4 Kazi Nazrul Islam Avenue, P.O. Box 164, Ramna, Dhaka 1000 Bangladesh
Dr. Akram Hossain Bangladesh Council of Scientific & Industrial Research (BCSIR), Analytical Research Division, Dr. Qudrati-e-Khuda Road, Dhanmondi, Dhaka 1205 Bangladesh
Prof. Dr.S. M. Imamul Huq Department of Soil, Water & Environment University of Dhaka, Dhaka 1000 Bangladesh
Tel: 880-2-9661900-59 Ext. 6130 (W), 880-2-8625680, 880-2-8612453 (H) Fax: 880-2-8615583, E-mail: [email protected], [email protected]
Professor Dr. Ali Hossain School of Environmental Science & Management,Independent University, Bangladesh House # 3, Road # 10, Baridhara, Dhaka 1212 Bangladesh
32
APPENDIX II. EXAMPLES OF FORMS AND CORRESPONDENCE
Att. «NAME»
«ADDRESS»
Atoms For Peace
Wagramer Strasse 5, P.O. Box 100, A-1400 Wien, Austria Phone: (+43 1) 2600 ¶ Fax: (+43 1) 26007 E-mail: [email protected] ¶ Internet: http://www.iaea.org
In reply please refer to: Analytical Quality Control Services Dial directly to extension: (+431) 2600 28226 E-mail: [email protected] ¶ Internet: http://www.iaea.org/programmes/aqcs
Seibersdorf, Date
Subject:
Samples of the Proficiency Test for the Determination of Total Arsenic Concentration in Water
Dear Participant,
Please find enclosed a set of samples together with the relevant documentation pertaining to the IAEA AQCS Proficiency Test for the Determination of Total Arsenic in Water. This Proficiency Test was initiated by the Technical Officer of the project BGD/8/018 Mr. Matthias ROSSBACH.
Please read the documentation carefully before commencing the analyses and return the sample receipt form to us at your earliest convenience.
In the package you should find 8 PE containers as the following:
7 samples including one Blank,
(Expected total arsenic concentration is between 10 and 300 µg/L).
100 mL standard solution 1000 (mg As/L)
You are kindly asked to perform 3 individual analysis of the 7 samples using different aliquots and to estimate the combined uncertainty of the whole analytical procedure. Analysis results and estimated combined uncertainties must be reported in the attached results and uncertainties reporting form (F-02).
4(O
ct. 0
4)
33
The enclosed standard solution 1000 (mg As/L) should be used to verify day-to-day calibration and to report any discrepancies between laboratory standard and the provided one.
In order to assess the analytical performance of the method, we would like to have information on the method validation parameters and the approach used in your laboratory for the evaluation of uncertainty components. Kindly refer to Method Validation and Combined Uncertainty Estimation Form (F-03) to fill the requested information.
In addition, it is important to have a short description of your method and quality control procedure applied in your laboratory. This information can be filled in the Method and Quality Control Procedure Description Form (F-04).
In the Reporting Form (F-01), the name of the person performing the analyses should be clearly indicated to distinguish the analyst from those in a supervisory role. You are requested to send the results before 15th of December 2004 to the attention of Mr. A. Shakhashiro e-mail: [email protected], who is the responsible for this exercise.
The participants data shall be evaluated according to the following three criteria:
A) The relative bias between the Analyst’s value and the IAEA value expressed as a relative bias in percentage:
%100Re ³-
=IAEA
IAEAAnalyst
ValueValueValue
biaslative
B) The Z-Score value calculated according to the following equation:
Where the target values for the standard deviation (s) shall be assigned on the basis of the reproducibility standard deviation (the standard deviation of the consensus mean after outlier rejection which expresses inter-laboratory precision)
C) The value of the U-test score to be calculated according to the following equation1:
22AnalystIAEA
AnalystIAEAtest
UncUnc
ValueValueU
+
-=
The calculated U-test value shall be compared with the critical values listed in the t-statistic tables to determine if the reported result differs significantly from the expected value at a given level of probability:
1 Brookes, C.J., Betteley, I.G. and Loxton, S.M.; Fundamentals of Mathematics and Statistics, Wiley 1979
sIAEAAnalyst
Score
ValueValuez
-=
34
For this proficiency test we have set the limiting value for the u-test parameter to 2.58 to determine if a result passes the test (U < 2.58).
Acceptance criteria:
Your results will be evaluated against the following acceptance criteria for accuracy and precision and assigned the status “passed” or “rejected” accordingly. A result must pass both criteria to be assigned the final status of “passed”.
1- Accuracy: result passes if
2258.2 AnalystIAEAAnalystIAEA UncUncValueValue +³¢- and < 30
2. Precision (dependent on the concentration level): the result passes if:
%10022
³öö÷
õææç
å+öö
÷
õææç
å
Analyst
Analyst
IAEA
IAEA
ValueUnc
ValueUnc
is less than, or equal to the reproducibility standard deviation as estimated for Z-Scores.
You are requested to report your results to us as a hard copy and return them to us by post. It is imperative that we receive the Reporting Forms duly completed as this will constitute your official results for this exercise and will be used as the definitive source of information for your laboratory. However, you should also submit your results to us electronically using the data reporting program provided in the package. In the event of results being sent near to the closing date for this exercise (15 December 2004) we will accept electronic input or fax submissions as constituting results submitted within the reporting period provided that the Reporting Forms are received by post within 2 weeks of the closing date.
It is planned to discuss the final results of this exercise in one of the forthcoming meetings.
Sincerely yours,
Umberto Sansone Head, Chemistry Unit Agency’s Laboratories Seibersdorf
35
To:
Analytical Quality Control Services, International Atomic Energy Agency, Agency’s Laboratories, A 2444 Seibersdorf, AUSTRIA.
Our Fax no.: + 43 1 2600 28222 Our E-mail: [email protected]
Acknowledgment of Receipt of Materials
BGD/8/018 PROFICIENCY TEST ON THE DETERMINATION OF TOTAL ARSENIC CONCENTRATION IN WATER
Please sign and return this page to confirm the receipt of this package, noting any missing or damaged items at the bottom of this page.
Address:
This package contains the following samples:
0101 PT Sample, 250 ml 0201 PT Sample, 250 ml 0301 PT Sample, 100 ml 0401 PT Sample, 250 ml 0501 PT Sample, 250 ml 0601 PT Sample, 100 ml 0701 PT Sample, 250 ml
1000 mg/L Arsenic standard solution (100mL),
I acknowledge the receipt of the samples described above.
------------------------------------ Signature and date
The following items were missing/broken:
36
Prof
icie
ncy
Tes
t on
the
Det
erm
inat
ion
of T
otal
Ars
enic
in
Wat
er
(AS/
BG
D/2
004)
Cod
e N
o.:
Plea
se in
clud
e na
me
and
addr
ess o
f res
pons
ible
ana
lyst
(if o
ther
than
giv
en o
r wro
ng).
Res
pons
ible
Ana
lyst
:
N
ame
and
Title
: …
……
……
……
……
.
La
bora
tory
/ D
ivis
ion:
…
……
……
……
……
.
Org
anis
atio
n / I
nstit
ute:
…
……
……
……
……
.
Stre
et /
Num
ber:
…
……
……
……
……
.
City
/ Po
stal
Cod
e:
……
……
……
……
….
C
ount
ry:
……
……
……
……
….
Te
l.:
……
……
……
……
….
Fa
x:
……
……
……
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….
E-
mai
l:
……
……
……
……
….
Si
gnat
ure:
…
……
……
……
……
.
Dat
e:
……
……
……
……
….
C
olla
bora
tors
: …
……
……
……
……
.
Plea
se se
nd b
ack
to:
…
……
……
……
……
.A
. Sha
khas
hiro
……
……
……
……
….
Ana
lytic
al Q
ualit
y C
ontro
l Ser
vice
s C
hem
istry
Uni
t, A
genc
y's L
abor
ator
ies S
eibe
rsdo
rf
A-2
444
Seib
ersd
orf -
Aus
tria
Tel:
+ 43
1 2
600
2822
6 Fa
x: +
43
1 26
00 2
8222
Em
ail:
a.sh
akha
shiro
@ia
ea.o
rg
Cus
tom
er N
umbe
r
Cus
tom
er N
umbe
rC
usto
mer
Num
ber
Cus
tom
er N
umbe
rC
usto
mer
Num
ber
For
IAE
A u
se o
nly!
«CU
NO
»
«CO
MM
NU
M»
37
Prof
icie
ncy
Tes
t on
the
Det
erm
inat
ion
of T
otal
Ars
enic
in W
ater
(AS/
BG
D/2
004)
You
r est
imat
es
Indi
vidu
al D
eter
min
atio
ns
to
tal
D
ate
of
Uni
t A
vera
ge
Unc
.*
atSa
mpl
e m
easu
rem
ent
Sam
ple
num
ber
(µg/
L)V
alue 1
Unc
.1*
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Stan
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L)(s
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D
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the
sam
e un
its a
s res
ults
(µg/
L)
If n
ot e
noug
h sp
ace
plea
se c
opy
this
pag
e.
38
Proficiency Test on the Determination of Total Arsenic in Water (AS/BGD/2004)
Measurement Results – Method Validation and Uncertainty Estimation
Please provide us with the following information related to method validation: 1- Did you perform method validation?
2- If yes, kindly submit the obtained validation parameters such as: Minimum detection limit , Repeatability limit, Reproducibility limit, Recovery coefficient
3- Please describe your approach for evaluation of uncertainty components and give the formula used for calculation of the expanded uncertainty.
4- You are kindly asked to list the sources of uncertainties included in the estimation of the combined uncertainty.
Remark:In practice, there are many possible sources of uncertainty in a measurement, both, of random nature or manifested as bias, including:
1) reproducibility of measurement; 2) bias or drift of measurement; 3) uncertainty in calibration process; of blank; in instrument readings (e.g. peak integration) 4) uncertainties of calibration sources; in sample preparation (mass, dilution, etc.).
These sources of uncertainty are not necessarily independent and some my be combined in 1). Of course, these possible sources of uncertainty are not an exhaustive list. Individual standard uncertainties may be estimated from repeated observations (any valid statistical method for treating data) or by using all relevant information which may include previous measurement data, experience with or general knowledge of the behaviour and properties of relevant materials and instruments, manufacturers specifications, data provided in calibration and other certificates, and uncertainties assigned to reference data taken from handbooks. EURACHEM Guide on Quantifying Uncertainty and Method validation in Analytical Measurements should be used as a general guidance. Copies can be downloaded from http://www.eurachem.ul.pt/guidesanddocuments.htm
If you have further questions regarding uncertainty evaluation do not hesitate to contact AQCS.
If not enough space please add separate sheets to this page.
39
Proficiency Test on the Determination of Total Arsenic in Water (AS/BGD/2004)
_________________________________________________________________________________________________________________
1. DESCRIPTION OF SAMPLE PREPARATION METHOD _________________________________________________________________________________________________________________
_________________________________________________________________________________________________________________
2. DESCRIPTION OF MEASUREMENT METHOD _________________________________________________________________________________________________________________
_________________________________________________________________________________________________________________
3. DESCRIPTION OF QUALITY CONTROL PROCEDURE _________________________________________________________________________________________________________________
Use of blanks, CRM, Control samples, duplicate, replicate, spike sample and control charts. Kindly report quality control data.