Abstract
A rapid method for the determination of dimetridazole and ipronidazole in feeds is described. The compounds are extracted from a borate buffer (pH 8.65) with benzene, partitioned into IN HC1, and then partitioned back into benzene from a basic aqueous phase. The benzene extract is concentrated and injected onto a nonpolar (Apiezon L) gas chromatographic column for determination by 63Ni electroncapture detection. Recoveries from feeds of various composition, spiked at 0.2 ppm with both dimetridazole and ipronidazole, ranged from 70 to 115%; for the same feeds spiked at 1 ppm or more, the recoveries were greater than 80%. Carbadox, furazolidone, levamisole, oxytetracycline, chlortetracycline, sulfamethazine, sulfaquinoxaline, arsanilic acid, piperazine, penicillin, and commonly added vitamins and minerals do not interfere. A 2-dimensional thin layer chromatographic system is presented as a means of additional identification.
