Determination of dimetridazole and ipronidazole in feeds at cross-contamination levels.
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 1N HCl, 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 electron-capture 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.
Hughes
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Food and Drug Administration, Kansas City, MO 64106.
D000821:Animal Feed / Q000032:analysis*; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D004131:Dimetridazole / Q000032:analysis*; D004563:Electrochemistry; D005506:Food Contamination / Q000032:analysis*; D007491:Ipronidazole / Q000032:analysis*; D009593:Nitroimidazoles / Q000032:analysis*
D009593:Nitroimidazoles; D007491:Ipronidazole; D004131:Dimetridazole