A Sensitive Enzyme Immunoassay for the Detection of Atrazine Based upon Sheep Antibodies

Abstract

A sensitive enzyme immunoassay for the detection of atrazine has been developed on the basis of sheep antibodies. Sheep were immunized with an immunogen prepared by coupling 2-aminohexanecarboxylic acid-4-isopropylamino-6-ethylamino-1, 3, 5-triazine to keyhole limpet hemocyanin. They produced antibodies with high affinity for atrazine. An enzyme immunoassay (EIA) was optimized with a peroxidase-atrazine tracer on microtitre plates. The assay with a detection limit of 0.03 ppb permits direct measurement of water samples without concentration or clean-up steps. Cross-reactivities above 10 % were only detected for propazine, which is not used in most European countries. Validation showed good correspondence of EIA and GC/MS with a correlation coefficient of r = 0.982.