INCREASED SENSITIVITY AND SELECTIVITY OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR THE DETERMINATION OF ATRAZINE BY USE OF NONIONIC SURFACTANTS

Different non-ionic detergents have been investigated for their use in a competitive enzymatic immunoassay for the determination of atrazine . Addition of surfactants enhances the activity of the horseradish per oxidase and modifies the selectivity by changing the cross-reactivity of other triazine herbicides. This allows a confirmation of the analyt e identity without using different antibodies. If the addition of a su rfactant leads to a different result in the analyte quantification, th e presence of cross-reacting compounds is likely. In combination with the cloud point extraction the detection limit can be improved by a fa ctor of ten (8 ng/l).