Page:NIOSH Manual of Analytical Methods - 2003.pdf/2

 1,1,2,2-TETRABROMOETHANE: METHOD 2003, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4.

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6. 7. 8.

EQUIPMENT:

Tetrahydrofuran (THF), chromatographic quality and free from peroxides.* 1,1,2,2-Tetrabromoethane, ≥98% pure.* Hexane, chromatographic quality.* Calibration stock solution, 89 mg/mL. Dissolve 0.89 g (300 µL at 20 °C) 1,1,2,2-tetrabromoethane in tetrahydrofuran to make 10 mL of solution. Prepare fresh daily. Desorption efficiency (DE) stock solution, 237 µg/µL. Dissolve 2.37 g (800 µL at 20 °C) 1,1,2,2-tetrabromoethane in hexane to make 10 mL of solution. Nitrogen, purified. Hydrogen, purified. Air, filtered.


 * See SPECIAL PRECAUTIONS.

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2. 3.

4. 5. 6. 7. 8. 9. 10.

Sampler: glass tube, 7 cm long, 6-mm OD, 4-mm ID, flame-sealed ends with plastic caps, containing two sections of 20/40 mesh silica gel (front = 150 mg; back = 75 mg) separated by a 2-mm plug of urethane foam. A plug of silylated glass wool precedes the front section. A 3-mm plug of urethane foam follows the backup section. Pressure drop across tube must be <3.4 kPa at 1 L/min airflow. Tubes are commercially available. Personal sampling pump, 0.2 to 1 L/min, with flexible connecting tubing. Gas chromatograph, flame ionization detector, integrator and column (page 2003-1). Vials, 2-mL, with PTFE-lined caps. Pipet, 1-mL, with pipet bulb. Volumetric flasks, 10-mL. Syringes, 500-µL, readable to 10 µL. Syringes, 10-µL, readable to 0.1 µL. U-tube, 25 cm x 15-mm ID, with glass stopcocks. Temperature bath, 75 °C.

SPECIAL PRECAUTIONS: THF is a serious fire risk [flash point (open cup) = -15 °C]. Explosive peroxides can form in THF during exposure to air in the absence of an inhibitor. THF vapor irritates the eyes and respiratory tract and cause headache, dizziness and narcosis. THF liquid can irritate the skin. If THF is distilled, distill in the presence of ferrous sulfate or other reducing agent. Store THF under nitrogen in a dark glass or metal container. 1,1,2,2-Tetrabromoethane is toxic, narcotic and can irritate the eyes and skin [3]. n-Hexane is a serious fire risk [flash point (closed cup) = -30 °C]. Inhalation of n-hexane vapor can irritate the upper respiratory tract and cause depression of the central nervous system. n-Hexane as a liquid can cause dermatitis and irritate the eyes. Work in a well-ventilated fume cabinet, wear gloves, avoid inhalation of vapors and protect solvents from sparks and open flame.

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 0.2 and 1 L/min for a total sample size of 50 to 100 L. Cap the samplers. Pack securely for shipment.

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