Page:NIOSH Manual of Analytical Methods - 2519.pdf/2

 ETHYL CHLORIDE: METHOD 2519, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1.

2. 3. 4. 5.

EQUIPMENT:

Eluent: carbon disulfide,* chromatographic quality, containing 0.4% (v/v) nonane as internal standard. Ethyl chloride, 99.7%.* Nitrogen, purified. Hydrogen, prepurified. Air, filtered, compressed.



See SPECIAL PRECAUTIONS.

1. Sampler: two glass tubes connected in series with a short piece of plastic tubing; each tube 10 cm long, 8 mm OD, 6 mm ID, containing 20/40 mesh activated (600 °C) coconut shell charcoal (front tube = 400 mg; back tube = 200 mg). A plug of silylated glass wool is placed at each end of each tube. Four plastic caps are required for sealing the tubes after use. Pressure drop across sampler less than 3.4 kPa (2.5 cm Hg) at 1 L/min airflow. 2. Personal sampling pump, 0.02 to 0.05 L/min, with flexible connecting tubing. 3. Gas chromatograph, FID, integrator and column (page 2519-1). 4. Vials, glass, serum, 3-mL, with PTFE-lined rubber septa and crimp seals. 5. Syringes, 0.5- and 5-mL. 6. Syringe, gas-tight, 10-mL. 7. Syringe needle, 22-gauge.

SPECIAL PRECAUTIONS: Carbon disulfide is toxic and an extreme fire and explosion hazard (flash point = -30 °C). Ethyl chloride is a narcotic and toxic [3]. Work with these only in a hood and away from spark sources. 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 0.02 and 0.05 L/min for a total sample size of 0.3 to 3 L. Separate the front and back tubes immediately after sampling. Cap the tubes. Pack securely for shipment.

SAMPLE PREPARATION: 5.

6. 7.

Place the front and back sorbent sections of the sampler in separate vials. Discard the glass wool plugs. Seal each vial with a septum and crimp seal. Insert a syringe needle through the septum to serve as a vent. Add 2.0 mL eluent to each vial with a syringe. Remove the syringe needle from the septum. Allow to stand 30 min with occasional agitation.

CALIBRATION AND QUALITY CONTROL: 8.

Calibrate daily with at least six working standards over the range 0.01 to 16 mg (0.004 to 6 mL of ethyl chloride gas at 20 °C and 101 kPa) ethyl chloride per sample. Use serial dilutions for the smallest concentrations. a. Add 2.0 mL eluent to each of a series of vials. Attach septum with crimp seal to each vial.

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