DEVELOPMENT AND OPTIMIZATION OF AN IMMUNOAFFINITY-BASED SOLID-PHASE EXTRACTION FOR CHLORTOLURON

The determination of trace organics such as pesticides in biological and environmental samples require rapid, easy-to-use, reliable sample preparation procedures. Solid-phase extraction using silica or bonded silicas has proven useful for broad-range screening. We have used antisera to chlortoluron immobilised onto silica as a ''tailor-made'' solid-phase extraction system. The chlortoluron can be selectively retained and eluted using a simple phosphate buffered saline/ethanol mixture. Preliminary studies have demonstrated that the immune column has a high volume breakthrough (at least 11 of water) and can retain up to 500 ng of chlortoluron. Quantitative recovery from tap water, river water, drinking water, plasma and urine is achieved along with an HPLC trace free from co-eluting compounds at the chlortoluron retention time.