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EPICHLOROHYDRIN: METHOD 1010, Issue 2, dated 15 August 1994 - Page 2 of 4
REAGENTS:
- Carbon disulfide, chromatographic quality.*
- Epichlorohydrin, reagent grade.*
- Nitrogen, purified.
- Hydrogen, prepurified.
- Air, filtered.
- Calibration stock solution, 9.45 mg/mL. Dissolve 80 µL epichlorohydrin in 10 mL CS2.
*See SPECIAL PRECAUTIONS.
EQUIPMENT:
- Sampler: glass tube, 7 cm long, 6-mm OD, 4-mm ID, flame-sealed ends with plastic caps, 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.
- Personal sampling pump, 0.01 to 0.2 L/min, with flexible tubing.
- Gas chromatograph, FID, integrator and column (page 1010-1).
- Vials, glass, 2-mL, PTFE-lined caps.
- Pipet, 1-mL, with pipet bulb.
- Syringes, 10- and 100-µL.
- Volumetric flasks, 1- and 10-mL.
- Metal file.
SPECIAL PRECAUTIONS: Carbon disulfide is toxic and extremely flammable (flash point = 30 °C); work with it only in a hood. Epichlorohydrin is a strong irritant and sensitizer and may cause kidney injury [4].
SAMPLING:
- 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 0.2 L/min for a total sample size of 2 to 30 L.
- Cap the samplers with plastic (not rubber) caps and pack securely for shipment.
SAMPLE PREPARATION:
- 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 CS2 to each vial. Attach crimp cap to each vial.
- Allow to stand 30 min with occasional agitation.
CALIBRATION AND QUALITY CONTROL:
- Calibrate daily with at least six working standards over the range 1 to 1200 µg epichlorohydrin per sample.
- Add known amounts of calibration stock solution to CS2 in 10-mL volumetric flasks and dilute to the mark.
- Analyze together with samples and blanks (steps 11 and 12).
- Prepare calibration graph (peak area vs. µg epichlorohydrin).
- Determine desorption efficiency (DE) at least once for each lot of charcoal used for sampling in
