Validation of two immunoassay methods for environmental monitoring of carbaryl and 1-naphthol in ground water samples

Two formats (microtiter plates and magnetic particles) of sensitive enzyme-linked immunosorbent assays (ELISA) for carbaryl determination have been compared to the EPA method 531.1 (liquid chromatography-post-column derivatization-fluorescence detection, LC-PCR-FD). An immunoassay developed for 1-naphthol determination has also been evaluated to monitor previous exposure to carbaryl in natural water samples. Matrix effect of this kind of water on the immunoassays is negligible and no sample preparation has found to be necessary other than buffering the samples. It is possible to perform a high number of analyses in a short period of time. A close correspondence was found for the results obtained when spiked and well water samples were split for analysis by ELISA and by LC-PCR-FD. Both methods are compared in terms of precision, reliability, reproducibility and their utility as screening tools. Application of those methods to the direct determination of carbaryl and 1-naphthol in ground water samples of the aquifer Campo de Nijar (Almeŕia, Spain) is reported.