Page:NIOSH Manual of Analytical Methods - 7702.pdf/1

 LEAD BY FIELD PORTABLE XRF Pb

MW: 207.19 (Pb) 223.19 (PbO)

METHOD: 7702, Issue 1

CAS: 7439-92-1 (Pb) 1317-3608 (PbO)

RTECS: OF7525000 (Pb) OG1750000 (PbO)

EVALUATION: FULL

OSHA: 0.05 mg/m3 NIOSH: <0.1 mg/m3; blood lead 60 µg/100 g ACGIH: 0.05 mg/m3; BEI blood 30 µg/ 100 mL

PROPERTIES:

7702

Issue 1: 15 January 1998

soft metal; d 11.3 g/mL @ 20 C; MP 327.5 C; BP 1740 C; valences +2, +4 in salts

SYNONYMS: elemental lead and lead compounds except alkyl lead

SAMPLING SAMPLER:

MEASUREMENT

FILTER (0.8-µm, 37-mm, mixed cellulose ester membrane)

TECHNIQUE:

FLOW RATE: 1 to 4 L/min

X-RAY FLUORESCENCE (XRF), PORTABLE, L-SHELL EXCITATION (e.g., 109 Cd source) NOTE: Performance parameters are based upon research conducted with the NITON® 700 XRF [1].

3

VOL-MIN: -MAX:

570 L @ 30.0 µg/m [1] 1900 L @ 9.0 µg/m3

SHIPMENT:

routine

ANALYTE:

lead

SAMPLE STABILITY:

stable

CALIBRATION:

lead thin-film standards (Micromatter Co., or equivalent); internal instrument calibration

BLANKS:

2 to 10 field blanks per set RANGE:

17 to 1500 µg of Pb per sample [1]

ACCURACY ESTIMATED LOD: 6 µg of Pb per sample [1] RANGE STUDIED: 0.1 to 1514.6 µg/m3 (as Pb) (based upon lead mass loadings) BIAS: PRECISION ( ACCURACY:

0.069 [1] rT

):

0.054 @ 10.3 to 612 µg Pb per sample ±16.4%

APPLICABILITY: This method was evaluated for air samples on filters only. The working range of this method is 0.017 mg/m3 to 1.5 mg/m3. This is a field portable analytical method, particularly useful for the analysis of initial exposure assessment samples, or for applications where laboratory analysis is impractical. Additionally, the method is non-destructive; samples analyzed in the field can later be analyzed in a laboratory. The method is applicable to all elemental lead forms, including lead fume, and all other aerosols containing lead. INTERFERENCES: The presence of bromine will cause XRF readings for lead to be elevated, resulting in a positive bias error. Other interferences may exist in other XRF instruments. OTHER METHODS: Laboratory-based methods include atomic spectrophotometric methods following hot plate acid digestion: NIOSH methods 7082 (flame atomic absorption spectrophotometry) [2], 7105 (graphite furnace atomic absorption spectrophotometry) [3], and 7300 (inductively coupled plasma atomic emission spectrophotometry) [4]. A field-portable analytical method for lead air filter samples using ultrasound/ASV has been developed, NIOSH Method 7701[5]. A field-portable screening method by spot test kit has been developed, NIOSH Method 7700 [6].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition