DEVELOPMENT OF AN ELISA FOR THE ANALYSIS OF ATRAZINE METABOLITES DEETHYLATRAZINE AND DEISOPROPYLATRAZINE

A highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) is described for the detection of the atrazine metabolites deethylatrazine and deisopropylatrazine. Polyclonal antibodies were raised in rabbits by immunization with a hapten-bovine serum albumin (BSA) conjugate containing 32 hapten residues/molecule of BSA. An ELISA with a peroxidase (POD) hapten tracer was optimized in microtiter plates. A concentration of 50% B/B0 was found at 0.20-mu-g/L for deethylatrazine and at 0.28-mu-g/L for deisopropylatrazine. Limits of determination for deethylatrazine and for deisopropylatrazine were reached at approximately 0.01-mu-g/L, i.e., well below the maximum concentration permitted by EC guidelines for drinking water. The assay did not require concentration or cleanup steps for drinking water or groundwater samples. Validation experiments confirmed a good accuracy and precision. Since deethylatrazine is the main atrazine metabolite found in water samples from these regions, this test yields fairly accurate results for deethylatrazine concentrations in environmental water samples. If deisopropylatrazine is present in the water samples, estimates for the sum parameter of the two atrazine metabolites are obtained.