HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF 4,4'-METHYLENEDIANILINE IN HUMAN URINE

A method is described for the determination of urinary 4,4'-methylenedianiline (MDA) by high-performance liquid chromatography (HPLC). MDA was extracted from hydrolyzed urine using C18 solid-phase extraction columns. The extract was analyzed by reversed-phase HPLC with electrochemical detection at a cell potential of 0.8 V. The method was very sensitive (detection limit 2.5-mu-g/l) and quantitation using 4,4'-ethylenedianiline as an internal standard correlated well with results by gas chromatography - mass spectrometry. Run-to-run precision (n = 25) averaged 8.9%. In analysis of more than 160 potentially exposed workers, MDA was detected in less than 20% of the urines and concentrations ranged up to 210-mu-g MDA per g of creatinine.