HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF PRIMARY AROMATIC-AMINES IN URINE AFTER DERIVATIZATION TO AN AZO-DYE WITH 2-AMINOANTHRACENE

A sensitive HPLC method for the determination of primary aromatic amin es (anilino compounds) is described. Samples were prepared by derivati zation of the substrate to an azo dye with 2-aminoanthracene (2-AA). 2 -AA was found to react with the diazonium salts prepared from substitu ted anilines such as 4-halo, -sulfonyl, -carboxyl, -nitro or -acetyl d erivatives, but not 4-hydroxy or alkyl derivatives. In this work, thre e model compounds [sulfanilamide, 4-aminobenzoyl-beta-alanine and 4-am inobenzoic acid (PABA)] were used to test the linearity and accuracy o f the method. Chromatographic separation was carried out using a rever sed-phase column (ODS) and ultraviolet detection at 279 nm. Good linea rity for the three compounds was found within the range 50-2000 ng/ml. The intra-day coefficient of variation for the three compounds (at 10 0, 500, 1000 ng/ml) was below 10%. Using this method, the urinary excr etion of PABA and its metabolites was studied after oral administratio n of PABA to rats.