only comment - myanmar standards · 2019. 9. 27. · niton® 700 xrf [1]. analyte: lead...

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DMMS NIOSH 7700: 1996,

7702: 1998 & 7082: 2017

Method for sampling and determination

of particulate lead

MYANMAR STANDARD (Draft)

NIOSH 1996

NIOSH 1998

NIOSH 2017

DRI 2019

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NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 5/15/96

LEAD in Air by Chemical Spot Test 7700

Pb MW: 207.19 CAS: 7439-92-1 RTECS: OF7525000

METHOD: 7700, Issue 1 EVALUATION: PARTIAL Issue 1: 15 May 1996

OSHA : 0.05 mg/m PROPERTIES: soft metal; d 11.3 g/cm ; MP 327.5 C;3

NIOSH:

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LEAD in Air by Chemical Spot Test: METHOD 7700, Issue 1, dated 15 May 1996 - Page 2 of 3


REAGENTS: EQUIPMENT:

1. Rhodizonate-based spot test kit 1. Sampler: Cellulose ester membrane filter,(Merck EM Quant Lead Test™ or equivalent). 0.8-µm pore size, 37-mm, in 2- or 3-pieceNOTE 1: Rhodizonate may degrade quickly cassette with cellulose backup pad.

over time. Follow manufacturer’s 2. Personal sampling pump, 1 to 4 L/min, withrecommendations for maintaining flexible connecting tubing.viability of reagents. 3. Sealable plastic bags.

NOTE 2: Performance parameters on page 4. Gloves, powderless, plastic7700-1 apply only to Merck EMQuant Test kit (See APPENDIX).

SPECIAL PRECAUTIONS: None

SAMPLING:

1. Calibrate each personal sampling pump with a representative sampler in line.2. Sample at an accurately known flow rate between 1 and 4 L/min (2 L/min recommended) for a total sample

size of 10 to 240 L.

SPOT TESTING (Qualitative measurement):

3. Don a clean pair of gloves.4. Using an appropriate tool, remove the top portion of the filter cassette (after sample has been collected for

desired time period).5. Apply the spot test to the center of the filter, following manufacturer's instructions.6. Record results as positive for lead if a characteristic color change is observed, or negative if no

characteristic color change is observed.NOTE: For rhodizonate-based lead spot tests (under acidic conditions), the characteristic color change

is from yellow or orange to pink or red [2]. LABORATORY ANALYSIS (Optional):

7. Re-cap filter cassettes.8. Place filter samples and test kit components in resealable plastic bag for shipment to laboratory.9. Analyze by NIOSH method 7300, 7082, 7105, or equivalent method for lead.

NOTE: The backup pad must be analyzed for lead that may have wicked through the filter duringqualitative measurement (step 5 above).

EVALUATION OF METHOD:

A commercial rhodizonate-based spot test kit (Merck EM Quant Lead Test ) was evaluated for its potentialTM

use in the detection of lead in airborne particulate [1]. Personal sampling pumps were used to collect 371 airsamples on cellulose ester membrane filters at various worksites where lead was a suspected air contaminant.Each filter sample was tested with an individual chemical spot test, and the samples (test kits included) werethen analyzed using NIOSH method 7105. Experimental data were statistically modeled in order to estimatethe performance parameters of the spot test kit (see APPENDIX). A positive reading was found at 95%confidence for lead mass values above 10.2 µg Pb per filter, while 95% confidence of a negative reading wasfound for lead masses below 0.57 µg Pb per filter.

MYANMAR STANDARD (Draft) DMMS NIOSH 7700: 1996

© NIOSH 1996 - All rights reserved ©DRI 2019 - All rights reserved

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LEAD in Air by Chemical Spot Test: METHOD 7700, Issue 1, dated 15 May 1996 - Page 3 of 3


REFERENCES:

[1] Ashley K, Fischbach TJ, Song R [in press]. Evaluation of a chemical spot test kit for the detection ofairborne particulate lead in the workplace. Am Ind Hyg Assoc J.

[2] Feigel F, Anger V [1972]. Spot tests in inorganic analysis. Amsterdam: Elsevier, pp. 282-287, 564-566,569.

[3] ASTM [1994]. ASTM E 1553, Standard practice for collection of airborne particulate lead duringabatement and construction activities. In: ASTM standards on lead-based paint abatement in buildings.Philadelphia, PA: American Society for Testing and Materials.

METHOD WRITTEN BY:

Kevin E. Ashley, Ph.D., DPSE/MRB

APPENDIX: CALCULATION OF PERFORMANCE PARAMETERS

Example calculations are illustrated here for the performance parameters of the Merck EM Quant Lead Test ;TM

performance parameters for other spot test kits should be estimated by statistical modeling before being usedfor field screening applications. Note that these calculations assume that the short-term exposures arerepresentative of a full 8-h workday.

Consider first the case of a positive test result after 5 min of sampling at 2.0 L/min (minimum lead mass of 0.57µg for a total sampling volume of 10 L):

0.057 µg Pb/L (X 1000 L/m ) = 57 µg Pb/m ,3 3

which is in excess of the OSHA permissible exposure limit (PEL) of 50 µg/m for an 8-h workday.3

Consider secondly the case of a negative test result after 2 h of sampling at 2.0 L/min (maximum lead massof 10.2 µg for a total sampling volume of 240 L):

0.0425 µg Pb/L (X 1000 L/m ) = 42.5 µg Pb/m ,3 3

which is below the OSHA PEL for an 8-h workday.

Similar computations may be carried out for other sampling volumes and spot test kits, provided that theperformance parameters for the test kits are known.



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NIOSH Manual of Analytical Methods (NMAM), Fourth Edition

LEAD BY FIELD PORTABLE XRF 7702

Pb MW: 207.19 (Pb) CAS: 7439-92-1 (Pb) RTECS: OF7525000 (Pb)223.19 (PbO) 1317-3608 (PbO) OG1750000 (PbO)

METHOD: 7702, Issue 1 EVALUATION: FULL Issue 1: 15 January 1998

OSHA: 0.05 mg/m3 NIOSH:

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LEAD BY FIELD PORTABLE XRF: METHOD 7702, Issue 1, dated 15 January 1998 - Page 2 of 4


REAGENTS:

1. None

EQUIPMENT:

1. Sampler: Mixed cellulose ester filter, 0.8-µmpore size, 37-mm diameter, with cellulose back-up pad, in a closed-faced cassette filter holder.

2. Personal sampling pump, 1 to 4 L/min, withflexible connecting tubing.

3. Field portable, L-shell X-Ray Fluorescence(XRF) instrument with a Cadmium-109 source.

4. Filter sleeve: thin cardboard with 37-mm dia.cut out, and covered with a light adhesivebetween two pieces of acetate (Mylar™)(NITON, Bedford, MA, or equivalent). NOTE: Material must be transparent to X-ray.

5. Filter test platform to hold the filter (specific toinstrument).

6. Forceps7. Thin film standard reference materials from 15

µg/cm2 to 150 µg/cm2 (Micromatter Co., DeerHarbor, WA), or equivalent [7,8].

SPECIAL PRECAUTIONS: None

SAMPLING:

1. Calibrate each sampling pump with a representative sampler in line. 2. Sample at an accurately known flow rate (1 to 4 L/min) for a total sample size of approximately 1000 L.

Do not exceed a filter loading of 2 mg total dust.

SAMPLE PREPARATION:

3. With forceps, transfer the MCE filter without the backup pad to a filter sleeve. The sleeve materialmust be transparent to X-rays (see EQUIPMENT, Item 4). NOTE: Take special care when removing the filter from the backup pad to avoid loss of lead-

containing dust.4. Place the filter into 37-mm opening and seal with Mylar™ film to prevent losses and allow undisturbed

analysis of the filter. 5. Place the sealed filter onto the filter test platform of the instrument for analysis.

NOTE: The NITON® 700 Series XRF has a filter test platform that allows for three readings with nosubstrate effect.

CALIBRATION AND QUALITY CONTROL:

6. Start XRF and allow a 30-minute warm-up period. The instrument will conduct an internal self-calibration.

7. Using thin film standards [8], verify the internal calibration to within ± 5% of the calibration standard.Use a minimum of three standards at concentrations of 15 µg/cm2, 150 µg/cm2, and one standardconcentration between these two values.

8. Restart the instrument as needed to assure instrument accuracy prior to sample analysis. NOTE: When the thin film standard measurements are not within the specified parameters, the

instrument may need to be recalibrated at the factory. 9. Analyze one thin film standard every 2 hours to check for instrument drift. 10. Repeat step 7 when all analyses are completed as a post-calibration check.

MEASUREMENT:



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C WV

, mg/m 3

11. Set instrument parameters and analyze filter samples as specified by the manufacturer. The following

measurement technique is based upon the NITON® 700 XRF. a. Analyze the middle of the sample filter first (see Figure 1, M). b. Allow the instrument to take a one source-minute reading (This may take longer than one real-time

minute, depending upon the source strength). A one source-minute reading will assure the accurateL-shell reading necessary for the analysis of lead air filter samples.

c. Analyze the filter sample at the top of the filter for one source minute (see Figure 1, T). d. Analyze the filter sample at the bottom of the filter for one source minute (see Figure 1, B). e. The instrument software uses an algorithm that converts the three readings in µg/cm2 to an

analytical result in µg of lead per sample. This result will be displayed following the third filterreading [1].

f. Analyze one standard every 2 hours (step 8). g. Repeat three-reading calibration check following completion of analyses (step 8).

CALCULATIONS:

12. Using the measured lead concentration, W (µg), calculate the concentration, C (mg/m3), of lead inthe air volume sampled, V (L):

NOTE: µg/L mg/m3


This method was validated on field samples [1] by collecting lead particulate samples from bridge leadabatement projects. Airborne concentrations of lead within the containment of a sand blasting bridgelead abatement project ranged from 1 to 10 mg/m3. Area samples were collected for periods of timeranging from 15 seconds to 2 hours. This sampling protocol yielded 61 filter samples with lead loadingsranging between 0.1 to 1514.6 µg of lead per sample. Four personal samples were collected from ahand-scraping bridge lead abatement project for a total sample size of 65. The samples were firstanalyzed using a non-destructive, field portable XRF method. Samples subsequently were subjected toconfirmatory analysis by the laboratory based NIOSH method 7105, Lead by GFAAS [3]. The methodwas statistically evaluated according to the NIOSH Guidelines for Air Sampling and Analytical MethodDevelopment and Evaluation [9]. The overall precision (rT) of the XRF method was calculated at 0.054with a 95% confidence interval (CI) of 0.035 to 0.073, and the bias was 0.069 with a 95% CI of 0.006 to1.515. The XRF method accuracy was determined to be ± 16%; however, at the upper 90% CI, theaccuracy is ± 27%. Since the confidence interval includes the ± 25%, meeting the NIOSH accuracycriteria of ± 25% is inconclusive. However, the samples used to evaluate this method were fieldsamples. Laboratory prepared aerosol samples would be expected to give better precision. Additionally,the XRF method is non-destructive; samples analyzed in the field can subsequently be analyzed in alaboratory using a method with greater accuracy, as needed. The filter sleeve used with the NITON®700 Series XRF used a Mylar film to cover and seal the 37-mm filter. The lead particulate on the surfaceof the filter came into contact with the Mylar™ film. Both the Mylar™ film and the filter were digestedwith nitric acid and hydrogen peroxide as is specified in NIOSH Method 7105 [3].

REFERENCES:

[1] Morley JC [1997]. Evaluation of a portable x-ray fluorescence instrument for the determination oflead in workplace air samples [Thesis]. Cincinnati, OH: University of Cincinnati, Department ofEnvironmental Health, College of Medicine.

[2] NIOSH [1994]. Lead by FAAS: Method 7082. In: Eller PM, Cassinelli ME, eds. NIOSH Manual ofAnalytical Methods (NMAM), 4th ed. Cincinnati, OH: National Institute for Occupational Safety and



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Health, DHHS (NIOSH) Publication No. 94-113.[3] NIOSH [1994]. Lead by GFAAS: Method 7105. In: Eller PM, Cassinelli ME, eds. NIOSH Manual of

Analytical Methods (NMAM), 4th ed. Cincinnati, OH: National Institute for Occupational Safety andHealth, DHHS (NIOSH) Publication No. 94-113.

[4] NIOSH [1994]. Elements: Method 7300. In: Eller PM, Cassinelli ME, eds. NIOSH Manual ofAnalytical Methods (NMAM), 4th ed. Cincinnati, OH: National Institute for Occupational Safety andHealth, DHHS (NIOSH) Publication No. 94-113.

[5] NIOSH [1994]. Lead by ultrasound/ASV: Method 7701 (supplement issued 1/15/98). In: Eller PM,Cassinelli ME, eds. NIOSH Manual of Analytical Methods (NMAM), 4th ed. Cincinnati, OH: NationalInstitute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 98-119.

[6] NIOSH [1994]. Lead in air by chemical spot test: Method 7700 (supplement issued 5/15/96). In:Eller PM, Cassinelli ME, eds. NIOSH Manual of Analytical Methods (NMAM), 4th ed. Cincinnati,OH: National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 96-135.

[7] National Institute of Standards and Technology, Standard Reference Material Program, StandardReference Material 2579, Lead paint film on Mylar sheet for portable X-ray fluorescence analyzers,Gaithersburg, MD 20899.

[8] Micromatter Co., XRF Calibration Standards, P.O. Box 123, Deer Harbor, Washington, 98243,Phone (360) 3 76-4007.

[9] NIOSH [1995]. Kennedy, E.R., Fishbach, T.J., Song, R., Eller, P.M., Shulman, S.S.. Guidelines forAir Sampling and Analytical Method Development and Evaluation. Cincinnati, Ohio: NationalInstitute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 95-117.

METHOD WRITTEN BY: J. Clinton Morley, MS, NIOSH/DSHEFS

,

Figure 1: Analysis of a 37-mm filter using XRF (XRF windows identified as M, T, and B are 2 cm x 1 cm)



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NIOSH Manual of Analytical Methods (NMAM), Fifth Edition

LEAD by Flame AAS 7082

Pb MW: 207.19 (Pb) CAS: 7439-92-1 (Pb) RTECS: OF7525000 (Pb)

MW: 223.19 (PbO) CAS: 1317-36-8 (PbO)RTECS: OG1750000 (PbO)

METHOD: 7082, Issue 3 EVALUATION: FULL Issue 1: 15 February 1984 Issue 3: 12 July 2017 OSHA: 0.050mg/m3 NIOSH: 0.050 mg/m3 OTHER OELs: [1-3]

PROPERTIES: soft metal; d 11.3 g/cm3; MP 327.5 °C valences +2, +4 in salts

SYNONYMS: elemental lead and lead compounds, except alkyl lead

SAMPLING SAMPLER: FILTER (0.8-µm cellulose ester membrane)

or INTERNAL CAPSULE, cellulose acetate dome with inlet opening attached to filter

FLOW RATE: 1 to 4 L/min

VOL-MIN: 200 L @ 0.05 mg/m3 -MAX: 1500 L

SHIPMENT: routine

SAMPLE STABILITY: stable at least 7 weeks [4]

BLANKS: 2 to 10 field blanks per set

ACCURACY RANGE STUDIED: 0.13 to 1.7 mg/m3 [8]

BIAS: -3.1%

OVERALL PRECISION (𝐒𝐒�𝐫𝐫𝐫𝐫): 0.07 [5,6]

ACCURACY: ±17.6%

MEASUREMENT TECHNIQUE: ATOMIC ABSORPTION

SPECTROPHOTOMETER, FLAME

ANALYTE: lead

ASHING: conc. HNO3, 6 mL + 30% H2O2, 1 mL; 140°C

FINAL SOLUTION: 10% HNO3, 10 mL

FLAME: air-acetylene, oxidizing

WAVELENGTH: 283.3 nm

BACKGROUND CORRECTION: D2 or H2 lamp, or Zeeman

CALIBRATION: Pb2+ in 10% HNO3

RANGE: 10 to 200 µg/sample [6,7]

ESTIMATED LOD: 2.6 µg/sample [8]

PRECISION (𝐒𝐒�𝐫𝐫): 0.03 [5]

APPLICABILITY: The working range is 0.05 to >1 mg/m3 for a 200-L air sample. The method is applicable to elemental lead, including Pb fume, and all other aerosols containing lead. This is an elemental analysis, not compound specific. Aliquots of the samples can be analyzed separately for additional elements. This method has been updated to include internal capsule samplers.

INTERFERENCES: Use D2 or H2 continuum or Zeeman background correction to control flame or molecular absorption. High concentrations of calcium, sulfate, carbonate, phosphate, iodide, fluoride, or acetate can be corrected for.

OTHER METHODS: This method combines and replaces P&CAM 173 [7] and S341 [8] for lead. NIOSH Methods 7300 (ICP-AES), 7701 (ASV) and 7105 (GFAAS) are alternative analytical methods. NIOSH Method 7505 is specific for lead sulfide. A consensus standard method, ASTM D6785, has been published [9].



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LEAD by Flame AAS: METHOD 7082, Issue 3, dated 12 July 2017 - Page 2 of 7


REAGENTS:

1. Nitric acid, conc., trace metal grade* 2. Nitric acid, 10% (v/v). Add 100 mL conc.

HNO3 to 500 mL water; dilute to 1 L 3. Hydrogen peroxide, 30% H2O2 (w/w),

reagent grade.* 4. Calibration stock solution, 1000 µg/mL Pb.

Commercial standard or dissolve 1.00 g Pb metal in minimum volume of (1+1) HCl and dilute to 1 L with 1% (v/v) HCl. Store in a polyethylene bottle. Stable > one year.

5. Air, compressed, filtered. 6. Acetylene 7. Distilled or deionized water

*See SPECIAL PRECAUTIONS.

EQUIPMENT:

1. Sampler: Cellulose ester filter or cellulose acetate internal capsule attached to mixed cellulose ester membrane filter, 0.8-µm pore size, 37-mm diameter, in 2-piece cassette filter holder.

2. Personal sampling pump, 1 to 4 L/min, with flexible connecting tubing.

3. Atomic absorption spectrophotometer with an air-acetylene burner head and background correction.

4. Lead hollow cathode lamp or electrode dischargeless lamp.

5. Regulators, two-stage, for air and acetylene. 6. Beakers, Phillips, 125-mL, or Griffin, 50-mL

with watch glass covers.** 7. Volumetric flasks, 10- and 100-mL.** 8. Assorted volumetric pipets, as needed.** 9. Hotplate, surface temperature 140 °C.

10. Bottles, polyethylene, 100-mL. ** Clean all glassware with conc. nitric acid and rinse thoroughly with distilled or deionized water before use.

SPECIAL PRECAUTIONS: Wear appropriate personal protection during sampling activities and analysis. It is essential that suitable gloves, eye protection, laboratory coat, etc., be used when working with the chemicals. Concentrated nitric acid is an irritant and may burn skin. Perform all acid digestions in a fume hood. Hydrogen peroxide is a strong oxidizing agent, a strong irritant, and corrosive to the skin. Wear gloves and eye protection.

SAMPLING:

1. Calibrate each personal sampling pump with a representative sampler in line. NOTE: See NMAM guidance chapters for discussion on sampling.

2. Sample at an accurately known flow rate between 1 and 4 L/min (± 5%) for up to 8 h for a total sample size of 200 to 1500 L for TWA measurements. Do not exceed a filter loading of approximately 5 mg total dust. NOTE: Filter overloading can be assessed by periodic visual checks. See NMAM guidance chapters for

additional discussion on filter capacity. SAMPLE PREPARATION:

3. Open the cassette filter holders and transfer the samples and blanks to clean beakers. NOTE: If internal capsules are not used, wipe the internal cassette surfaces with a polyvinyl alcohol

wipe or cellulosic wipe wetted with deionized water, and add the wipe to the digestion vessel (to transfer non-filter aerosol deposits into the digestion vessels) [10].



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NOTE: The following sample preparation gave quantitative recovery (see EVALUATION OF METHOD) [8]. Steps 4 through 9 of Method 7300 or other quantitative ashing techniques may be substituted, especially if several metals are to be determined on a single filter.

NOTE: The Appendix gives a microwave digestion procedure, which may be necessary for complete recovery of lead from some matrices, especially epoxy-based paint.

4. Add 3 mL conc. HNO3, and 1 mL 30% H2O2 and cover with a watch glass. Start reagent blanks at this step. NOTE: If PbO2 is not present in the sample, the 30% H2O2 need not be added [6,8].

5. Heat on 140 °C hotplate until volume is reduced to about 0.5 mL. 6. Repeat two more times using 2 mL conc. HNO3 and 1 mL 30% H2O2 each time. 7. Heat on 140 °C hotplate until ca. 0.5 mL liquid remains. 8. When sample is dry, rinse the watch glass and walls of the beaker with 3 to 5 mL 10% HNO3. Allow the

solution to evaporate to dryness. 9. Cool each beaker and dissolve the residues in 1 mL conc. HNO3.

10. Transfer the solution quantitatively to a 10-mL volumetric flask and dilute to volume with distilled water. NOTE: If the concentration (M) of any of the following is expected to exceed the lead concentration (M)

by 10-fold or more, add 1 mL 1 M Na2EDTA to each flask before dilution to volume: CO32-, PO43-, I-, F-, CH3COO- [8]. If Ca2+ or SO42- are present in 10-fold or greater excess, make all standards and samples with 1% (w/w) La2+ [7].

CALIBRATION AND QUALITY CONTROL:

11. Prepare a series of working standards covering the range 0.25 to 20 µg/mL Pb (2.5 to 200 µg Pb per sample). a. Add aliquots of calibration stock solution to 100-mL volumetric flasks. Dilute to volume with 10%

HNO3. Store the working standards in polyethylene bottles and prepare fresh weekly. b. Analyze the working standards together with the blanks and samples (steps 14 and 15). c. Prepare a calibration graph of absorbance vs. solution concentration (µg/mL)

12. Aspirate a standard for every 10 samples to check for instrument drift. 13. Check recoveries with at least one spiked media blank per 10 samples. Use method of standard

additions occasionally to check for interferences.

MEASUREMENT:

14. Set spectrophotometer as specified by the manufacturer and to conditions on page 7082-1. NOTE: An alternate wavelength is 217.0 nm [11]. Analyses at 217.0 nm have slightly greater sensitivity,

but poorer signal-to-noise ratio compared to 283.3 nm. Also, non-atomic absorption is significantly greater at 217.0 nm, making the use of D2 or H2 continuum, or Zeeman background correction mandatory at that wavelength.

15. Aspirate standards, samples, and blanks. Record absorbance readings. NOTE: If the absorbance values for the samples are above the linear range of the standards, dilute with

10% HNO3, reanalyze, and apply the appropriate dilution factor in the calculations.

CALCULATIONS:

16. Using the measured absorbances, calculate the corresponding concentrations (µg/mL) of lead in the sample, Cs, and average media blank, Cb, from the calibration graph.

17. Using the solution volumes (mL) of the sample, Vs, and media blanks, Vb, calculate the concentration, C (mg/m3), of lead in the air volume sampled, V (L):

𝐶𝐶 =𝐶𝐶𝑠𝑠𝑉𝑉𝑠𝑠 − 𝐶𝐶𝑏𝑏𝑉𝑉𝑏𝑏

𝑉𝑉,𝑚𝑚𝑚𝑚𝑚𝑚3

NOTE: µg/mL ≈ mg/m3.



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The predecessor to NIOSH 7082, Method S341 [8], was issued on October 24, 1975, and validated over the range 0.13 to 0.4 mg/m3 for a 180-L air sample, using generated atmospheres of lead nitrate [5]. Recovery in the range 18 to 72 µg Pb per sample was 98%, and collection efficiency of 0.8-µm mixed cellulose ester filters (Millipore Type AA) was 100% for the aerosols at the detection limit of 0.013 mg/m3. Subsequent studies on analytical recovery of 200 µg Pb per sample gave the following results [6,8]:

Species Digestion method Analytical recovery, % Pb metal HNO3 only 92.4 ± 4 Pb metal HNO3 + H2O2 103 ± 3 PbO HNO3 only 93 ± 4 PbS HNO3 only 93 ± 5 PbO2 HNO3 only 82 ± 3 PbO2 HNO3 + H2O2 100 ± 1 Pb in paint* HNO3 only 95 ± 6 Pb in paint* HNO3 + H2O2 95 ± 6 *Standard Reference Material #1579, U.S. National Institute of Standards and Technology

Additional collection efficiency studies were also done using Gelman GN-4 metrical cellulose acetate membrane filters for the collection of Pb fume, which had geometric mean diameter of 0.1 µm [5]. Mean collection efficiency for 24 sampling runs at flow rates between 0.15 and 4.0 L/min was >97 ± 2%. Overall precision, SrT, was 0.072 for lead nitrate aerosol [5,8] and 0.068 for Pb fume [6,8].

Evaluation information on internal capsule samplers may be found in NIOSH 7306 [12].

REFERENCES:

[1] ACGIH [2016]. TLVs® and BEIs® based on the documentation of the Threshold Limit Values for chemical substances and physical agents and Biological Exposure Indices. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists.

[2] Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area [2016]. List of MAK and BAT values 2016; Maximum Concentrations and Biological Tolerance Values at the Workplace. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co., http:// dx.doi.org/10.1002/9783527805983.

[3] Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) [no date]. GESTIS international limit values, http://limitvalue.ifa.dguv.de/. Date accessed: July 12, 2017.

[4] Marks GE, Knutsen EO [1975]. Complete testing of the NIOSH method for the determination of trace metals by atomic absorption spectrophotometry. Chicago, IL: IIT Research Institute, NIOSH contract no. CDC-99-74-48.

[5] Taylor DG, Kupel RE, Bryant JM. [1977]. Documentation of the NIOSH validation tests. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 77-185. Available from www.ntis.gov as accession no. PB274248

[6] Gutknecht WF, Ranade MH, Grohse PM, Damle A, O’Neal D [1981]. Heavy metal aerosols: Collection and dissolution efficiencies. Research Triangle Park, NC: Research Triangle Institute, Contract 210-79-0058, Available from www.ntis.gov as accession no. PB83-106740.



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[7] NIOSH [1979]. Method P&CAM 173. In: Taylor DG, ed. NIOSH manual of analytical methods. 2nd ed. Cincinnati, OH: U.S. Department of Health, Education and Welfare, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 77-157-A.

[8] NIOSH [1982]. Method S341. In: Taylor DG, ed. NIOSH manual of analytical methods. 2nd ed. Cincinnati, OH: U.S. Department of Health and Human Services, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 82-100.

[9] ASTM International [2013]. ASTM D6785, Standard test method for determination of lead in workplace air using flame or graphite furnace atomic absorption spectrometry. West Conshohocken, PA: ASTM International.

[10] Ashley K, Harper M [2013]. Closed-face filter cassette (CFC) sampling - Guidance of procedures for inclusion of material adhering to internal sampler surfaces. J Occup Environ Hyg 10:D29-D33.

[11] Perkin-Elmer Corporation [1976]. Analytical methods for atomic absorption spectrophotometry. Norwalk, CT: Perkin-Elmer Corporation.

[12] NIOSH [2015]. Method 7306. In: Ashley K, O’Connor PF, eds. NIOSH manual of analytical methods. 5th ed. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 14-151.

[13] DataChem Laboratories [no date]. In-house procedure for microwave sample digestion. Salt Lake City, UT: DataChem Laboratories. Unpublished.

[14] EPA [1986]. SW-846: Test methods for evaluating solid waste, Physical and chemical methods, 3rd ed. Washington, DC: U.S. Environmental Protection Agency.

[15] Kingston HM, Jassie LB, eds. [1988]. Safety guidelines for microwave systems in the analytical laboratory. In: Introduction to microwave acid decomposition: Theory and practice. Washington, DC: American Chemical Society.

[16] ASTM International [2011]. ASTM D1193, Standard specification for reagent water. West Conshohocken, PA: ASTM International.

[17] Kingston HM, Jassie LB, eds. [1988]. Introduction to microwave acid decomposition: Theory and practice. Washington, DC: American Chemical Society.

[18] Kingston HM [1988]. Quarterly Report, EPA IAG #DW1-393254-01-1.

[19] Binstock DA, Yeager WM, Grohse PM, Gaskill A [1989]. Validation of a method for determining elements in solid waste by microwave digestion, Draft technical report for RTI Project number 321U-3579-24. Research Triangle Park, NC: Research Triangle Institute.

METHOD REVISED BY:

Mark Millson, R. DeLon Hull, PhD, and Ronnee N. Andrews, PhD, NIOSH. S341 originally validated under NIOSH contract CDC-94-74-45; additional studies under NIOSH contract 210-79-0058.

James B. Perkins, David L. Wheeler, and Keith Nicholson, Ph.D., DataChem Laboratories, Salt Lake City, UT, prepared the microwave digestion procedure described in the Appendix.



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Disclaimer: Mention of any company or product does not constitute endorsement by NIOSH. In addition, citations to websites external to NIOSH do not constitute NIOSH endorsement of the sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these websites. All web addresses referenced in this document were accessible as of the publication date.

APPENDIX: MICROWAVE DIGESTION FOR LEAD IN PAINT CHIPS (AND OTHER MATRICES)

This procedure is an alternative to the procedure presented in the Sample Preparation section of this method. It provides a rapid, complete acid digestion prior to analysis by flame atomic absorption (FAA), heated graphite furnace atomic absorption (HGFAA), and inductively coupled plasma spectroscopy (ICP) [13].

Apparatus and Materials [14-19]

1. Microwave unit, to provide programmable power with a minimum of 574 W and programmable to within ± 10 W of the required power.

2. The microwave unit cavity shall be corrosion resistant as well as ventilated. All electronics are protected against corrosion for safe operation.

3. The system requires microwave transparent and reagent resistant vessels, such as perfluoroalkoxy alkane (PFA) digestion vessels (120-mL capacity), capable of withstanding pressures up to 7.5 ± 0.7 atm (760 ± 70 kPa). Vessels shall also be capable of controlled pressure relief at pressures exceeding 7.5 ± 0.7 atm (760 ± 70 kPa). Other, equivalent types of vessels designed to operate at temperatures and pressures required and recommended by manufacturer can be used.

4. A rotating turntable is employed to ensure homogeneous distribution of microwave radiation within the unit. The speed of the turntable should be a minimum of 3 rpm.

5. A safety concern relates to the use of sealed containers without pressure relief valves in the unit. Temperature is the important variable controlling the reaction. Pressure is needed to attain elevated temperatures but must be safely contained [15].

6. Polymeric volumetric ware in plastic (PTFE or polyethylene), 50- or 100-mL capacity. 7. Disposable polypropylene filter funnel. 8. Analytical balance, 300-g capacity, and minimum ± 0.001 g.

Reagents

1. Nitric acid, concentrated, spectroscopy grade. 2. Reagent Water. Reagent water shall be interference free. All references to water in the method refer to

reagent water that meets the ASTM Type 2 standard.

Procedure

1. Calibration of Microwave Equipment a. Calibrate microwave equipment in accordance with manufacturer's instructions. If calibration

instructions are not available, see EPA Method 3051 [14]. 2. All digestion vessels and volumetric ware must be carefully acid washed and rinsed with reagent

water. All digestion vessels should be cleaned by leaching with hot (1:1) nitric acid for a minimum of fifteen minutes, rinsed with reagent water, and dried in a clean environment

3. Sample Digestion a. Tare the PFA digestion vessel. b. Weigh out 0.1 g paint chip sample to the nearest 0.001 g into the tared PFA sample vessel. With

large paint chip samples, measure out a 2 cm2 piece, weigh to the nearest 0.001 g, and quantitatively transfer it to the vessel.



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c. Add 5.0 ± 0.1 mL concentrated nitric acid to the sample vessel in a fume hood. If a vigorous reaction occurs, allow the reaction to stop before capping the vessel. Cap the vessel and torque the cap to 16 N-m according to the manufacturer's directions. The sample vessel may be connected to an overflow vessel using PFA connecting tubes. Place the vessels in the microwave carrousel. Connect the overflow vessels to the center well of the unit.

d. Place the vessels evenly distributed in the turntable of the microwave unit. Any vessels containing 5 mL of nitric acid for reagent blank purposes are counted as sample vessels. When fewer than the recommended number of samples are to be digested, i.e., three samples plus one blank, the remaining vessels should be filled with 5 mL of nitric acid to achieve the full complement of vessels. This provides an energy balance since the microwave power absorbed is proportional to the total mass in the cavity [17]. Irradiate each group of samples to achieve a temperature of 180 °C. Temperature ramp times should be appropriate for the vessels used. A sample digestion program for 12 samples is presented in Table A1. Adjust power values depending upon the number of samples included in the microwave at one time.

TABLE A1. PROGRAM VARIABLES FOR PAINT CHIPS SAMPLE DIGESTION WITH NITRIC ACIDA

Stage 1 Stage 2 Stage 3 Power 90% 90% 0% Pressure (kPa) 375 750 --- Run time (min) 10 20 5 Time @ P (min) 5 15 --- Temperature (°C) 180 180 None applied AFor 12 microwave vessels that contain 0.1 g of sample and 5 mL of liquid per vessel

e. At the end of the microwave program, allow the vessels to cool to a temperature below the boiling point of concentrated nitric acid (or that of the acid mixture used) before removing them from the microwave unit. If sample loss is detected (e.g., material in overflow collection vessel, liquid outside liner), determine the reason for the loss (e.g., loss of vessel seal integrity, use of a digestion time longer than 30 minutes, too large a sample, or improper heating conditions). Once the source of the loss has been corrected, prepare a new sample beginning at step 2. If insufficient material is available for reanalysis, dilute remaining digestate and note that some sample loss may have occurred.

f. Uncap and vent each vessel in a fume hood. Transfer the sample to an acid-cleaned polyethylene bottle. Dilute to 25 mL using reagent water. If the digested sample contains particulates which may clog nebulizers or interfere with injection of the sample into the instrument, allow the sample to settle or filter it: Settling: Allow the sample to stand until the supernatant is clear (usually overnight is sufficient). If

it does not filter the sample. Filtering: Filter using disposable syringe filters, filter apparatus, etc. The filtering apparatus must be

thoroughly precleaned and rinsed with dilute nitric acid. Filter the sample through quantitative filter paper into a second acid-cleaned container.

The digestate is now ready for analysis for elements of interest using the appropriate method. 4. Calculations: Report the concentrations based on the actual weight of the original sample.



1.MMS cover.pdf6. (ii) NIOSH 7700 lead-final.pdf7. (iii) NIOSH 7702 lead-final.pdf8. (i) NIOSH 7082 lead-final.pdfLEAD by Flame AAS 7082 SAMPLING ACCURACY MEASUREMENT REAGENTS: EQUIPMENT: SAMPLING: CALIBRATION AND QUALITY CONTROL: MEASUREMENT: CALCULATIONS: EVALUATION OF METHOD: REFERENCES: APPENDIX: MICROWAVE DIGESTION FOR LEAD IN PAINT CHIPS (AND OTHER MATRICES)

only comment - myanmar standards · 2019. 9. 27. · niton® 700 xrf [1]. analyte: lead...

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