Determination of 4,4′-Methylene-dianiline in Hydrolysed Human Urine as Chloroformate Derivative Using Column Switching and Liquid Chromatography with UV Detection

Abstract

A liquid chromatographic method with UV-detection (λ=246 nm) is presented for determination of 4,4′-methylenedianiline (MDA, C.A.S No 101–77–9) in hydrolysed human urine. The method is based on a two-phase derivatization procedure with isobutylchloroformate. The formed chloroformate derivative was analysed on a octadecylsilyl column using isocratic elution with acetonitrile-water (75:25 v/v). The overall recovery for urine samples spiked with 32 μg MDA/1 was found to be 88 7plusmn; 4%. The calibration graph was linear in the investigated range (3–37 μg/1 urine) with a correlation coefficient of 0.997. The precision was 3.4% for urine samples spiked with 32 μg MDA/1 and the detection limit was 3 μg/1. Methyl-, ethyl-, isobutyl-benzyl-, 2-bromoethyl- and p-nitrobenzylchloroformate as derivatization reagents and clean-up procedures with extraction columns are discussed.