Page:NIOSH Manual of Analytical Methods - 1016.pdf/2

 TETRACHLORO-DIFLUOROETHANES: METHOD 1016, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2.

3. 4.

5.

6. 7. 8.

EQUIPMENT:

Carbon disulfide (CS 2), chromatographic quality.* 1,1,1,2-Tetrachloro-2,2-difluoroethane and 1,1,2,2-tetrachloro-1,2-difluoroethane, reagent grade.* Hexane, chromatographic quality. Calibration stock solution, 0.2 mg/µL. Dissolve 2 g analyte in CS 2 to prepare 10 mL solution. Prepare in duplicate. DE stock solution, 1 mg/µL. Dissolve 10 g analyte in hexane to prepare 10 mL solution. Prepare in duplicate. Nitrogen, purified. Hydrogen, prepurified. Air, filtered, compressed



See SPECIAL PRECAUTIONS.

1. Sampler: glass tube, 7 cm long, 6-mm OD, 4-mm ID, flame-sealed ends, containing two sections of activated (600 °C) coconut shell charcoal (front = 100 mg; back = 50 mg) separated by a 2-mm urethane foam plug. A silylated glass wool plug precedes the front section and a 3-mm urethane foam plug follows the back section. Pressure drop across the tube at 1 L/min airflow must be less than 3.4 kPa. Tubes are commercially available. 2. Personal sampling pump, 0.01 to 0.035 L/min, with flexible connecting tubing. 3. File, triangular. 4. Gas chromatograph, flame ionization detector, integrator and column (page 10161). 5. Vials, 2-mL, PTFE-lined caps. 6. Syringes, 10-µL, readable to 0.1 µL. 7. Volumetric flasks, 10-mL. 8. Pipets, 10- to 1000-µL.

SPECIAL PRECAUTIONS: Tetrachloro-1,2-difluoroethane has been determined to be a carcinogen [3]. Both analytes react with chemically-active metals such as sodium, potassium and beryllium or with powdered magnesium, aluminum and zinc. Hazardous products such as hydrogen chloride, hydrogen fluoride and carbon monoxide may be released when either analyte decomposes. Both analytes will attack some forms of plastics, rubber and coatings. Carbon disulfide is toxic and flammable; work with it only in a hood.

SAMPLING: 1. 2. 3. 4.

Calibrate each personal sampling pump with a representative sampler in line. Break the ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 and 0.035 L/min for a total sample size of 0.5 to 2 L. Cap the samplers. Pack securely for shipment.

SAMPLE PREPARATION: 5. 6. 7.

Place the front and back sorbent sections of the sampler tube in separate vials. Discard the glass wool and foam plugs. Add 1.0 mL CS 2 to each vial. Cap each vial. Allow to stand 30 min with occasional agitation.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94