Continuous immunochemical determination of pesticides via flow injection immunoanalysis using monoclonal antibodies against terbutryne immobilized to solid supports

Monoclonal anti-terbutryne antibodies were immobilized to polystyrene and glass beads, and the different immobilizations were compared for their applicability in flow injection immunoanalysis (FIIA). The immobilization methods used were (1) covalent immobilization of avidin via acetic acid/periodate to glass beads with subsequent coupling of biotinylated antibodies, (2) adsorption of avidin to polystyrene bends and coupling of biotinylated antibodies and (3) covalent immobilization of antibodies via glutardialdehyde to glass beads. In all cases, the methods were screened in micro-test-tubes. Immobilization methods 2 and 3 proved to be the most effective, and were therefore further tested for their use in the FIIA. Here, immobilization to glass beads gave the best performance, in terms of both reproducibility and the appearance of the peaks. The antibodies were regenerated after each assay at feast 60 times (methods 2 and 3). The signal declined during the sequential measurement of standards in the FIIA system, so a zero value (no analyte) was determined prior to each analyte standard. As a result, the analyte concentration was always expressed as the %B/B-0 value. A representative standard curve established for terbutryne showed a detection range of 0.01-5 mu g l(-1) and an IC50 of 0.1 mu g l(-1) (glass beads). This concentration range is useful for monitoring drinking water sources in the European Union.