Page:NIOSH Manual of Analytical Methods - 1614.pdf/5

 ETHYLENE OXIDE: METHOD 1614, Issue 2, dated 15 August 1994 - Page 5 of 6

[4] [5]

[6]

[7]

Review with Control Recommendations - Use of Ethylene Oxide as a Sterilant in Medical Facilities, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-200 (1977). Threshold Limit Values and Biological Exposure Indices for 1993-94, ACGIH, Cincinnati, OH (1993). NIOSH Testimony to USDOL at OSHA rulemaking hearing for ethylene oxide (July 20, 1983); also see Current Intelligence Bulletin 35, "Ethylene Oxide," U.S. Department of Health and Human Services, Publ. (NIOSH) 81-130 (May 22, 1981). NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of Health and Human Services Publ. (NIOSH) 81-123 (1981), available as GPO stock #17-033-00337-8 from Superintendent of Documents, Washington, D.C. 20402. Siggia, S. and J.G. Hanna. Quantitative Organic Analysis via Functional Groups, 4th ed., Chapter 5, John Wiley & Sons, Inc., New York, NY (1979).

METHOD REVISED BY: George Williamson, NIOSH/DPSE.

APPENDIX A: PREPARATION OF SOLID SORBENT Slowly add a mixture of 25 mL 48% hydrobromic acid and 125 mL acetonitrile to 75 g petroleum-based charcoal (SKC Inc., Lot 208) contained in a 500-mL round-bottom flask. Allow the slurry to cool to room temperature. Dry the coated charcoal by rotary evaporation using gentle heat and keep it overnight under vacuum at ambient temperature. The product is stable for four months when stored in a tightly sealed amber glass jar at room temperature [1]. Recovery may be lower as the sample medium ages. APPENDIX B: STANDARDIZATION OF NaOH 1. 2. 3. 4.

Transfer duplicate, accurately weighed, ca. 1.5-gram portions of KHP (W, mg) to separate 125mL Erlenmeyer flasks. Dissolve in 20 to 30 mL distilled water, warming if necessary. Add one drop phenolphthalein solution to each flask. Fill the burette with 0.5 N NaOH. Titrate, with constant mixing, to a pink endpoint in each flask. Record the volume, V (mL), of 0.5 N NaOH used. Calculate the normality, Nb, of the NaOH solution.

Nb

W (204.22

V)

.

APPENDIX C: STANDARDIZATION OF HCI IN PYRIDINE 1. 2. 3. 4. 5. 6. 7.

Pipet 40.0 mL 0.2 N HCl in pyridine into a 100-mL round-bottom flask. Add 4.0 mL benzene. Attach the flask to a water-cooled condenser and heat flask with a heating mantle to boiling. Reflux for 20 min. Cool to near room temperature. Add 5 mL distilled H 2O through condenser and collect washings in the flask. Remove reflux condenser and add a drop of phenolphthalein solution to the flask. Titrate, with mixing, 0.5 N NaOH from the burette to the flask to a pink endpoint. Record volume, Vb (mL), of NaOH used. Repeat steps 1 through 7 and average the results. Calculate the normality, oN, of the HClpyridine solution using Nb from APPENDIX B:

No

NbVb 40

.

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