National Institute for Occupational Safety and Health

“ Determine recovery from bubblers. a. Dilute portions of recovery stock solution with chloroform to prepare a series of spiking solutions in the range of interest. b. Add known quantities of ethylenimine in spiking solutions to bubblers containing 15-mL quantities of Folin's reagent. Prepare five samples at each of three levels over the range of interest. c. Prepare sample solutions (steps 5 through 10) and analyze (steps 13 and 14) . d. Calculate recovery, R (μg of ethylenimine found divided by μg of ethylenimine applied) . e. Prepare a graph of recovery versus μg of ethylenimine found. ”

“ Dissolve 0.40 g of 1,2naphthoquinone-4-sulfonic acid, sodium salt, in 100 mL of buffer solution. Dilute to 500 mL with water. Wrap flask with aluminum foil and refrigerate. Solution is stable for 5 days. Na 3PO 4 solution (0.5 M) . Dissolve 19 g of Na 3PO 4·12H2O in water to make 100 mL of solution. 4- (1-Aziridinyl) -1,2-naphthoquinone. See Appendix. Calibration stock solution, 500 μg/mL. Dissolve 125 mg of 4- (1-aziridinyl) -1,2naphthoquinone in chloroform to make 250 mL of solution. Recovery stock solution, 10 mg/mL. Dissolve 2.50 g of ethylenimine in chloroform to make 250 mL of solution. ”

“ Sample at 0.2 L/min for a sample size of 1 to 48 L. After sampling, use a pipet bulb to force air through the bubbler stem to dislodge ethylenimine derivative and recover sampling solution. Rinse the stem with 2 mL of chloroform, and add the wash to the bubbler. Seal the bubbler with a nonreactive stopper (PTFE or glass) . Do not seal with rubber. Protect the sample from light, and ship at 5 °C.
NIOSH Manual of Analytical Methods (NMAM) , Fourth Edition, 8/15/94 ETHYLENIMINE: METHOD 3514, Issue 2, dated 15 August 1994 - Page 3 of 4 SAMPLE PREPARATION: 5. 6. 7. 8. 9. 10. ”