DICHLORODIFLUOROMETHANE CCl2F2
MW: 120.91
METHOD: 1018, Issue 2
CAS: 75-71-8
RTECS: PA8200000
EVALUATION: FULL
OSHA : 1000 ppm NIOSH: 1000 ppm ACGIH: 1000 ppm (1 ppm = 4.95 mg/m 3 @ NTP)
PROPERTIES:
1018
Issue 1: 15 August 1987 Issue 2: 15 August 1994
gas; BP -29.8 °C; MP -158 °C: d 1.35 @ 21.1 °C; nonflammable
SYNONYMS: difluorodichloromethane; Refrigerant 12
SAMPLING SAMPLER:
SOLID SORBENT TUBES (two coconut shell charcoal tubes in series, 400/200 mg and 100/50 mg)
MEASUREMENT TECHNIQUE:
GAS CHROMATOGRAPHY, FID
ANALYTE:
dichlorodifluoromethane
FLOW RATE: 0.01 to 0.05 L/min
DESORPTION:
20 mL methylene chloride
VOL-MIN: -MAX:
1 L @ 1000 ppm 4L
INJECTION VOLUME:
1 µL
SHIPMENT:
refrigerated
SAMPLE STABILITY:
TEMPERATURE-INJECTOR: -DETECTOR: -COLUMN:
at least 7 days @ -10 °C
BLANKS:
2 to 10 field blanks per set
200 °C 260 °C 35 °C for 3 min, 15 °C/min to 75 °C, hold 6 min
CARRIER GAS:
He, 1.5 mL/min
COLUMN:
DB-1 fused silica capillary, 30 m x 0.32-mm ID, 1-µm film thickness or equivalent
CALIBRATION:
standard solutions of analyte in methylene chloride
RANGE:
5 to 30 mg per sample [1]
ACCURACY RANGE STUDIED:
2940 to 10,500 mg/m 3 [1]
BIAS:
- 1.8%
ˆ ): 0.063 [1] OVERALL PRECISION (S rT
ESTIMATED LOD: 0.03 mg per sample [1]
ACCURACY:
PRECISION (Sr):
± 12.8%
0.035 @ 7.4-30 mg per sample [1]
APPLICABILITY: The working ranges are 1000 to 6000 ppm dichlorodifluoromethane (5000 to 30,000 mg/m 3); 700 to 5700 ppm 1,2-dichlorotetrafluoromethane (5000 to 40,000 mg/m 3); and 300 to 4000 ppm chlorodifluoromethane (1000 to 14,000 mg/m 3) for a 1-L air sample. This method was first evaluated for dichlorodifluoromethane and 1,2-dichlorotetrafluoroethane with packed column gas chromatography [1]. The method was recently evaluated specifically for chlorodifluoromethane usin g capillary chromatography [3]. Capillary GC conditions for the separation of the three compounds were established.
INTERFERENCES: None identified.
OTHER METHODS: This combines and revises Methods S111 and S108 [2].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
