Page:NIOSH Manual of Analytical Methods - 7056.pdf/1

 BARIUM, soluble compounds

Ba

MW: 137.34

CAS: 7440-39-3

METHOD: 7056, Issue 2

RTECS: CQ8370000

EVALUATION: FULL

OSHA : 0.5 mg/m 3 NIOSH: 0.5 mg/m 3 ACGIH: 0.5 mg/m 3

7056

Issue 1: 15 August 1987 Issue 2: 15 August 1994

PROPERTIES: solubility @ 100 °C: BaCO 3 : 0.006 g/100 g H 2 O; BaCl 2 : 59 g/100 g H 2 O; Ba(NO 3 )2 : 34 g/100 g H 2 O; BaO: 91 g/100 g H 2 O

SYNONYMS: vary depending upon compound

SAMPLING

MEASUREMENT

SAMPLER:

FILTER (0.8-µm cellulose ester membrane)

TECHNIQUE:

ATOMIC ABSORPTION, FLAME

FLOW RATE:

1 to 4 L/min

ANALYTE:

barium ion (Ba 2+ )

VOL-MIN: -MAX:

50 L @ 0.5 mg/m 3 2000 L

EXTRACTION:

hot water leach, 10 mL, 10 min, twice; conc. HCl, 3 drops; evaporate to dryness

SHIPMENT:

routine

FINAL SOLUTION:

SAMPLE STABILITY:

stable

FLAME:

nitrous oxide-acetylene reducing

FIELD BLANKS:

2 to 10 field blanks per set

WAVELENGTH:

553.6 nm

CALIBRATION:

standard solutions of Ba 2+ in 5% HCl/1.1 mg/mL Na +

RANGE:

25 to 200 µg per sample [1]

ESTIMATED LOD:

2 µg per sample [1]

PRECISION (Sr):

0.025 @ 43 to 180 µg per sample [1]

5% HCl/1.1 mg/mL Na +, 5 mL

ACCURACY RANGE STUDIED: BIAS:

0.28 to 1.08 mg/m 3 [1] (168-L samples) - 0.55%

ˆ ): 0.054 [1] OVERALL PRECISION (S rT ACCURACY:

± 10.81%

APPLICABILITY: The working range is 0.13 to 10 mg/m 3 for a 200-L air sample. This method determines Ba 2+ in water-soluble barium compounds. Insoluble barium compounds (e.g., BaSO 4 ) require an ashing procedure.

INTERFERENCES: Ionization of barium in the flame is controlled by addition of sodium chloride to samples and standards. Calcium, at >0.1%, gives a positive interference unless background correction is used.

OTHER METHODS: This revises Method S198 [2].

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94