QUANTITATION OF ALACHLOR RESIDUES IN MONKEY URINE BY ELISA

An ELISA was used to quantitate the total residues of alachlor in monk ey urine samples. Rhesus monkeys (six of each gender) were administere d intravenously with [C-14]alachlor, and urine samples were collected from 0 to 120 h. Urinary residues from different time points were quan titated by immune response in an ELISA and by radioactivity. The immun e response was based on antibody crossreactivity toward three of the f ive major urinary metabolites of alachlor. The urinary concentrations of residues by both quantitation methods were expressed as parts per m illion equivalents of alachlor mercapturate, which was previously iden tified as the most abundant metabolite of alachlor in monkey urine. An alysis of 135 urine samples by radioactivity and by ELISA produced a c orrelation coefficient of 0.89. Time after dosing, gender, and dosing levels had no effect on the performance of the ELISA. The results sugg est potential application of an immunoassay as a biomonitoring tool fo r alachlor exposure.