Page:NIOSH Manual of Analytical Methods - 1018-2.pdf/1

 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