IMMUNOASSAY SCREENS FOR ALACHLOR IN RURAL WELLS - FALSE POSITIVES AND AN ALACHLOR SOIL METABOLITE

Unexpectedly high frequencies of positive responses have been observed in ELISA screening for alachlor in private rural wells, when samples were analyzed using the EnviroGard Alachlor Plate Kit, The majority of positive responses are false positives with respect to alachlor. In the false positive samples which have been tested, most of the positive response appears to be due to the ethanesulfonate metabolite of alachlor. The concentrations of ES are relatively high, even in samples collected months after alachlor application, suggesting that ES is relatively persistent and mobile in soil. Additional studies of ES are warranted, and ELISA alachlor screens may be useful in its study. © 1993, American Chemical Society. All rights reserved.