Page:NIOSH Manual of Analytical Methods - 7105.pdf/1

 LEAD by GFAAS

Pb

MW:

7105

207.19 (Pb); CAS: 7439-92-1 (Pb); RTECS: 223.19 (PbO) 1317-36-8 (PbO)

METHOD: 7105, Issue 2

OF7525000 (Pb) OG1750000 (PbO)

EVALUATION: PARTIAL

OSHA : 0.05 mg/m3 NIOSH: <0.1 mg/m3; blood Pb 60 µg/100 g ACGIH: 0.05 mg/m3

PROPERTIES:

Issue 1: 15 August 1990 Issue 2: 15 August 1994 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)

FLOW RATE:

1 to 4 L/min

VOL-MIN: -MAX:

1 L @ 0.05 mg/m3 1500 L

SHIPMENT:

MEASUREMENT TECHNIQUE:

ATOMIC ABSORPTION SPECTROPHOTOMETER, GRAPHITE FURNACE

ANALYTE:

lead

ASHING:

conc. HNO3, 3 mL; 30% H2O2; 1 mL; 140 C

routine FINAL SOLUTION: 10 mL 5% HNO3

SAMPLE STABILITY:

stable

WAVELENGTH:

283.3 nm

FIELD BLANKS:

2 to 10 field blanks per set

GRAPHITE TUBE:

pyrolytic coated

INJETION:

20 µL + 10 µL matrix modifier, DRY: 110 C, 70 sec; CHAR: 800 C, 30 sec; ATOMIZE: 1800 C, 5 sec.

ACCURACY

RANGE STUDIED:

not studied

BIAS:

not determined

OVERALL PRECISION ( ACCURACY:

rT):

not determined not determined

BACKGROUND CORRECTION: D2, H2, or Zeeman CALIBRATION:

Pb2+ in 5% HNO3

RANGE

0.05 to 100 µg per sample [1]

ESTIMATED LOD:

0.02 µg per sample [1]

PRECISION ( r):

0.049 [1]

APPLICABILITY: The working range is 0.002 to >1 mg/m3 for a 200-L air sample. If high concentrations are expected, the samples should be analyzed by flame AAS. 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 sample may be analyzed separately for additional elements.

INTERFERENCES: Use D2 or H2 continuum or Zeeman background correction to control molecular absorption. High concentrations of calcium, sulfate, carbonate, sulfate, carbonate, phosphate, iodide, fluoride, or acetate can be offset by an additional sample treatment step.

OTHER METHODS: This revises and replaces P&CAM 214 (2). Method 7300 (ICP-AES) is an alternate analytical method. Method 7505 is specific for lead sulfide by X-ray diffraction. Method 7082 is a flame AAS method, with a higher working range.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition