Page:NIOSH Manual of Analytical Methods - 1614.pdf/2

 ETHYLENE OXIDE: METHOD 1614, Issue 2, dated 15 August 1994 - Page 2 of 6 EQUIPMENT:

REAGENTS: 1. N,N-Dimethylformamide (DMF), high purity. 2. Isooctane (2,2,4-trimethylpentane), reagent grade. 3. Benzene, reagent grade.* 4. N-Heptafluorobutyrylimidazole (HFBl;Nheptafluorobutanoylimidazole; Alfa Chemical 01835). 5. Water, high purity (e.g., deionized distilled). 6. 2-Bromoethanol (2-FrEt), 95 to 98%. 7. Sodium hydroxide (NaOH), reagent grade. 8. Potassium hydrogen phthalate (KHP), reagent grade, dried at 90 C. 9. HCl, conc., reagent grade.* 10. Pyridine, reagent grade. 11. Phenolphthalein, 1% (w/v) in ethanol or methanol. 12. Hydrobromic acid (HBr), 48%, reagent grade.* 13. Charcoal, petroleum-based (SKC Lot 208 or equivalent, SKC, Eighty-Four, PA). 14. Ethylene oxide (EtO), liquid or gas, 99.7% purity.* 15. Sodium hydroxide, 0.5 N. Dissolve 20 g NaOH in distilled water to make 1 L of solution. Standardize with KHP to a phenolphthalein endpoint (APPENDIX B). 16. HCl in pyridine, 0.2 N. Dissolve 8.5 mL conc. HCl in pyridine to make 500 mL solution. Standardize (APPENDIX C). 17. Ethylene oxide stock solution,* ca. 40 µg/µL. Bubble EtO gas (or pipet 4 mL EtO liquid) into 85 mL benzene in a graduated cylinder until solution volume increases ca. 4 mL. Seal tightly and store in freezer. Standardize weekly (APPENDIX D). 18. HFBl, 2% in isooctane. Dissolve 2 mL HFBl in isooctane to make 100 mL solution. Store in refrigerator. 19. 5% Methane in argon.
 * 1) 31594, Alfa Products, Ward Hill, MA

1. Sampler: 6-mm OD x 4-mm ID x 45 mm glass tube, flame-sealed, with plastic caps, contaiing HBr-coated charcoal (see APPENDIX A), two sections, 100-mg front, 50-mg back, separated and contained with silanized glass wool plugs. Tubes are commercially available (Supelco Orbo-78, SKC 226-38-03, or equivalent. 2. Gas chromatograph, electron capture detector, integrator, and column (p. 1614-1). 3. Burette, 50-mL, 0.1-mL graduations. 4. Flask, round-bottom, 100-mL, with groundglass joint. 5. Condenser, reflux, with ground-glass joint to fit round-bottom flask. 6. Heating mantle, with heat control, to fit round bottom flask. 7. Graduated cylinder, glass, 100-mL, with stopper that seals tightly. 8. Vials, glass, 5-mL, with PTFE-lined screw caps. 9. Pipets, volumetric, 2- to 500-µL and 1-, 2-, 4, and 40-mL, with pipet bulb. 10. Syringes. 11. Vials, glass, 2-mL, with PTFE-lined septum screw caps. 12. Flasks, Erlenmeyer, 125-mL. 13. Gloves. 15. Fume hood. 16. File, triangular. 17. Evaporator, rotary.

See SPECIAL PRECAUTIONS.

SPECIAL PRECAUTIONS: Ethylene oxide and benzene are toxic and serious fire and explosion hazards; they are also suspect carcinogens [4-6]. Hydrobromic and hydrochloric acids are eye, skin, and inhalation hazards [6]. Work with these substances only in a hood. Use protective gloves. SAMPLING: 1. 2. 3.

Calibrate each personal sampling pump with a representative sampler in line. Break ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.05 and 0.15 L/min for a total sample size of 1 NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94