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
