Page:NIOSH Manual of Analytical Methods - 1012.pdf/1

 	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