Development of Immunoassays for the Detection of the Fungicide Penconazole and Its Urinary Metabolite

Monoclonal antibodies were raised to haptens containing moieties common to both the triazole fungicide penconazole and its proposed primary urinary metabolite (4-(2,4-dichlorophenyl)-5-(H-1,2,4-triazol-1-yl)pentoic acid). The monoclonal antibody 2E4 was used to develop competitive ELISA assays where binding of antibody to immobilized haptens conjugated to BSA competed with penconazole or its metabolite in solution. At pH 4.0 and pH 8.0, penconazole was detected with an IC50 of 1.0−1.2 μg/L respectively and at pH 4 penconazole metabolite was detected with an IC50 of 0.9 μg/L. These assays were specific for penconazole and/or its metabolite compared to other triazole fungicides. The immunoassay conditions optimal for penconazole metabolite (pH 4.0) were used and applied to the analysis of spiked human urine, and following sample extraction using a C18 SPE column, could detect 0.5 μg/L metabolite. This is the first report of an immunoassay to the urinary metabolite of penconazole, an assay with application in the monitoring of occupational and non-occupational exposure to this commonly used pesticide.