AN ENZYME-IMMUNOASSAY FOR THE DETERMINATION OF METHABENZTHIAZURON

A sensitive enzyme immunoassay is described for the determination of the urea herbicide methabenzthiazuron. The assay is carried out with polyclonal antibodies, which were raised in rabbits by immunization with a methabenzthiazuron-BSA conjugate containing five methabenzthiazuron residues per molecule. The ELISA was optimized on microtiter plates with a peroxidase-methabenzthiazuron tracer. The middle of the test (50% B/B0) was found at 1.0-mu-g/l. The lower detection limit of methabenzthiazuron is c. 0.05-mu-g/l. Samples can be measured up to 10-mu-g/l methabenzthiazuron (upper detection limit). The assay does not require concentration or clear-up steps for drinking or ground water samples. Validation experiments showed a good accuracy and precision. Work with monoclonal antibodies is in progress.