Characterization of s-triazine antibodies and comparison of enzyme immunoassay and biotin-avidin enzyme immunoassay for the determination of s-triazine

Triazines have been used widely as herbicides and known to cause environmental contamination. For developing ELISA of s-triazines, six kinds of s-triazine derivatives (one from simazine, one from atrazine and four from cyanuric chloride) which contained a C3- or C6-carboxylic acid group bridge were prepared. These derivatives were conjugated to bovine serum albumin (BSA) for the use of immunogens and to KLH for the use of coating ligands on the microtiter plate wells. Polyclonal antibodies produced from rabbit or sheep using atrazine-BSA (1b-BSA) and simazine-BSA (1a-BSA) immunogens. These antibodies were characterized and biotinylated for the use of enzyme immunoassay (EIA). We evaluated EIA and biotin-streptavidin mediated EIA in terms of the sensitivities and specificities with these antibodies. The results in both assay systems showed that coating ligand synthesized from atrazine derivative was better than that from simazine derivative. Comparing binding ability between C3-carboxylic acid and C6-carboxylic acid spacers of N-alkyl group in s-triazine ring, C3-carboxylate-KLH (2c-KLH) derived from atrazine showed better sensitivity for the both assay systems. The detection limit was found to be 0.01 ppb in biotin-streptavidin mediated EIA (B-Av EIA). Comparing IC₉₀ values of EIA (0.5 ppb) and B-Av EIA (0.05 ppb), B-Av EIA was able to detect one order lower concentration range of atrazine than EIA.