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
