QUANTITATION OF ALACHLOR RESIDUES IN MONKEY URINE BY ELISA

An ELISA was used to quantitate the total residues of alachlor in monkey urine samples. Rhesus monkeys (six of each gender) were administered intravenously with [C-14]alachlor, and urine samples were collected from 0 to 120 h. Urinary residues from different time points were quantitated by immune response in an ELISA and by radioactivity. The immune response was based on antibody crossreactivity toward three of the five major urinary metabolites of alachlor. The urinary concentrations of residues by both quantitation methods were expressed as parts per million equivalents of alachlor mercapturate, which was previously identified as the most abundant metabolite of alachlor in monkey urine. Analysis of 135 urine samples by radioactivity and by ELISA produced a correlation coefficient of 0.89. Time after dosing, gender, and dosing levels had no effect on the performance of the ELISA. The results suggest potential application of an immunoassay as a biomonitoring tool for alachlor exposure.