Improved Enzyme Immunoassay for the Analysis of S-Triazines in Water Samples

A highly sensitive enzyme immunoassay is described for the detection of the s-triazines, propazine and atrazine. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 35 atrazine residues per molecule. A microtitration plate ELISA was optimized with a peroxidase-atrazine tracer. The middle of the test (50% B/B0) was found at 10 ng/l propazine and 20 ng/l atrazine, i.e. well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l and for propazine of around 0•1 ng/l could be reached. The assay did not require concentration or clean-up steps for drinking or ground water samples. Validation experiments showed a good accuracy and precision. Since propazine is not used in most European countries, this test can be applied to obtain fairly accurate results for atrazine concentrations in environmental water samples from these regions.