Studies on monochlorobenzene poisoning Part I: Quantitative determination of urinary metabolites (p-chlorophenylmercapturic acid and conjugates of 4-chlorocatechol) of monochlorobenzene by high-performance liquid chromatography.

The quantitative determination of major urinary metabolites of monochlorobenzene by high-performance liquid chromatography(HPLC) was studied. Urinary p-chlorophenylmercapturic acid was assayed directly and urinary monoglucuronide and ethereal sulphate conjugates of 4-chlorocatechol were assayed as 4-chlorocatechol after being hydrolyzed. The results obtained were as follows. 1. Para-chlorophenylmercapturic acid. a. Urinary p-chlorophenylmercapturic acid of rats given monochlorobenzene by subcutaneous injection was recognized as a separate peak on the HPLchromatogram against the other peaks in normal rat urine. b. A linear relationship was obtained between the quantity of p-chlorophenylmercapturic acid and its peak height on HPLchromatogram up to 5ng. 2. 4-Chlorocatechol. a. 4-Chlorocatechol in the hydrolyzate of the urine of rats given monochlorobenzene by subcutaneous injection was recognized as a separate peak on the HPLchromatogram against the other peaks of normal rat urine. b. A linear relationship was obtained between the quantity of 4-chlorocatechol and its peak height on the HPLchromatogram up to 0.3μg.