Page:NIOSH Manual of Analytical Methods - 8302.pdf/4

MBOCA in urine: METHOD 8302, Issue 2, dated 15 August 1994 - Page 4 of 4 GUIDES TO INTERPRETATION: Linch, et al. [1] reported exposed workers having MBOCA at concentrations up to 370 µg/L of urine. No other reports have been found in the literature. CAL/OSHA has recommended that urinary MBOCA levels should not exceed 100 µg/L [6].

EVALUATION OF METHOD: Spiked urine specimens containing MBOCA concentrations of 4, 30 and 150 µg/L urine were analyzed in groups of 10 for each concentration. Precision ( Sr) over the above analytical range was found to be 0.08 [2].

REFERENCES: [1]

[2] [3] [4] [5] [6]

Linch, A. L., G. B. O'Connor, J. R. Barnes, A. S. Killian, and W. E. Neeld. Methylene-bis-Ortho-Chloroaniline (MOCA): Evaluation of Hazards and Exposure Control, Am. Ind. Hyg. Assoc. J., 32, 802-819 (1971). NIOSH Manual of Analytical Methods, 2nd ed., Vol. 7, P&CAM 342, U.S. Department of Health and Human Services, Publ. (NIOSH) 82-100 (1981). Special Hazard Review with Control Recommendations for 4,4'-Methylenebis-(2-Chloroaniline), U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 78-188 (1978). Van Roosmalen, P. B., A. L. Klein, and I. Drummond. An Improved Method for Determination of 4,4'-Methylenebis-(2-Chloroaniline) (MOCA) in Urine, Am. Ind. Hyg. Assoc. J., 40, 66-69 (1979). Tietz, N. W. Fundamentals of Clinical Chemistry , 2nd ed., pp. 994-999, W.B. Saunders, Co., Philadelphia, PA (1976). California Occupational Safety and Health Administration (CAL/OSHA), Title 8, Sec. 5215; General Industry Safety Orders, 4,4'-Methylenebis(2-chloroaniline), Register 81, No. 22 (May 30, 1981).

METHOD WRITTEN BY: William P. Tolos, NIOSH/DBBS.

APPENDIX: FLORISIL CLEANUP AND ANALYSIS (for urine containing <5 mg MBOCA/L) 1. Concentrate the extract (the organic layer from step 14) to approximately 0.5 mL under a gentle stream of nitrogen at 30 °C in a waterbath. 2. Place a small glass wool plug in a chromatographic column. Add 1.6 g of 10% deactivated Florisil. Top with 2 cm of anhydrous Na 2SO 4. 3. Pre-rinse the packed column with 10 mL hexane. 4. Transfer the 0.5 mL of derivatized extract to the column with a Pasteur pipet. Add the extract just as the level of hexane rinse is even with the Na 2SO 4 layer. 5. Quickly rinse the extract tube with several additional small quantities of hexane. Do not allow the level of rinse to fall below the Na 2SO 4 layer. 6. Discard the eluted pre-rinse. 7. Elute the column with 10 mL of 40% benzene/hexane (v/v). The solvent mixture should not fall below the Na 2SO 4 layer; discard the eluate. 8. Elute the column with 10 mL of 100% benzene. Save the eluate and concentrate to 1 mL. 9. Inject 1 µL of the concentrated benzene fraction into the GC that has been set to the conditions described on page 8302-1.

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