Page:NIOSH Manual of Analytical Methods - 1612.pdf/2

 PROPYLENE OXIDE: METHOD 1612, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4. 5. 6. 7. 8.

EQUIPMENT:

Propylene oxide (PrO), reagent grade.* Carbon disulfide (CS 2), chromatographic quality.* Hexane, reagent grade.* Calibration stock solution, 10 mg/mL, in carbon disulfide. Desorption efficiency (DE) stock solution, 150 mg/mL, in hexane. Nitrogen, purified. Hydrogen, purified. Air, compressed, filtered.

1.

2. 3.

See SPECIAL PRECAUTIONS. 4. 5. 6.

7. 8.

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 connecting tubing. Shipping container, with bagged refrigerant. Gas chromatograph, FID, integrator, and column (page 1612-1). Vials, 2-mL, PTFE-lined caps. Syringes, 10-µL, readable to 0.1 µL, and other convenient sizes for preparing standards. Volumetric flasks, 10-mL. Pipet, 1-mL.

SPECIAL PRECAUTIONS: Carbon disulfide is toxic and a dangerous fire and explosion hazard (flash point = -30 °C). Propylene oxide is a suspect carcinogen and is extremely flammable (flash point = -37 °C) [4]. Hexane is extremely flammable. Work with these 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 0.2 L/min for a total sample size of 0.5 to 5 L. Cap the samplers and pack securely for shipment in an insulated container with bagged refrigerant. Refrigerate upon receipt.

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. Attach cap to each vial. Allow to stand 30 min with occasional agitation.

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