DIFLUORODIBROMOMETHANE 1012 CBr2F2 MW: 209.83 CAS: 75-61-6 RTECS: PA7525000 METHOD: 1012, Issue 2
EVALUATION: PARTIAL
OSHA: 100 ppm NIOSH: 100 ppm ACGIH: 100 ppm
(1 ppm = 8.58 mg/m³ @ NTP)
Issue 1: 15 May 1985 Issue 2: 15 August 1994
PROPERTIES: liquid; d 2.35 g/mL @ 0 °C; BP 24.5 °C; FP −141 °C; VP 83 kPa (620 mm Hg; 82% v/v) @ 20 °C; non-flammable
SYNONYMS: dibromodifluoromethane; Freon 12B2 SAMPLING
MEASUREMENT
SAMPLER: SOLID SORBENT TUBES (2 tubes in tandem, each with 150 mg coconut shell charcoal)
TECHNIQUE:
GAS CHROMATOGRAPHY, FID
ANALYTE:
difluorodibromomethane
FLOW RATE: 0.01 to 0.2 L/min
DESORPTION:
1.0 mL 2-propanol; stand overnight
VOL-MIN: -MAX:
INJECTION VOLUME:
5 µL
2.5 L 10 L
SHIPMENT: routine
TEMPERATURE-INJECTION: 200 °C -DETECTOR: 300 °C -COLUMN: 60 °C
SAMPLE STABILITY: not determined BLANKS:
CARRIER GAS:
N2, 30 mL/min
COLUMN:
3 m × 6 mm OD stainless steel, packed with 10% FFAP on 100/120 Chromosorb WHP or equivalent
470 to 1875 mg/m³ [1] (10-L samples)
CALIBRATION:
difluorodibromomethane in 2-propanol
2.5%
RANGE:
2 to 20 mg per sample
2 to 10 field blanks per set ACCURACY
RANGE STUDIED: BIAS:
OVERALL PRECISION ( ): 0.09 [1]
ESTIMATED LOD: 0.4 mg per sample
ACCURACY:
PRECISION ( ):
±18.8%
0.067 @ 4 to 19 mg per sample [1]
APPLICABILITY: The working range is 200 to 2000 mg/m³ (23 to 230 ppm) for a 10-L air sample. Difluorodibromomethane is used in the synthesis of dyes, pharmaceuticals, and quaternary ammonium compounds, and as a fire extinguishing agent. INTERFERENCES: Carbon disulfide has about the same GC retention volume as difluorodibromomethane [1]. OTHER METHODS: This is Method S107 in a revised format [2].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition
