Metabolites of 1,2,3,4-tetrachlorobenzene in monkey urine.

[14C(U)]-Labeled 1,2,3,4-tetrachlorobenzene was administered orally to squirrel monkeys. Urine was collected from these animals, pooled and analyzed for metabolites by thin-layer chromatography, high-performance liquid chromatography, and gas chromatography-mass spectroscopy. N-Acetyl-s-(2,3,4,5-tetrachlorophenyl) cysteine was shown to be the major metabolite and accounted for 85% of the radioactivity found in urine. A minor metabolite was identified as 2,3,4,5-tetrachlorophenol. This study demonstrates for the first time that an N-acetyl cysteine conjugate has been isolated and identified as metabolite of a chlorinated benzene. This pattern of chlorobenzene metabolism is significantly different from the one obtained with the rat and rabbit, where tetrachlorophenols constitute the major metabolites.