DETERMINATION OF WEATHERED ATRAZINE RESIDUES IN SOIL BY ENZYME-IMMUNOASSAY AND HPLC - AN EVALUATION STUDY

This study was conducted to evaluate a specific enzyme immunoassay (EIA) for the quantification bf weathered atrazine residues in soils at concentration levels below 50 mu g/kg. Samples of widely differing soil types were analysed with EIA before clean-up and HPLC after clean-up of the soil extracts. On average EIA slightly overestimated the atrazine concentration compared to HPLC by 1.2 mu g/kg. The coefficient of determination was r(2)=0.95. EIA proved tb be a valid analytical method and especially effective when many soil samples have to be screened for atrazine residues or illegal atrazine application. In cases where EIA indicates atrazine residues, analysis with HPLC-DAD can follow up, providing detailed information on its metabolites deethyl-, deisopropyl-, and hydroxyatra-zine.