Determination of Dimetridazol in Animal Feedingstuffs and Additive Premixes by HPLC with UV Detection. Interlaboratory Comparison Test of the Method

Abstract

An HPLC method of determination of dimetridazol in premixes of additives and feedingstuffs was developed. Dimetridazol is extracted from a fodder sample with aqueous methanol and, after purification of the extract on Sep-Pak Alumina B, it is determined by HPLC on C18 reverse phase with UV detection at 309 nm.. The determination limit is 2.9 mg.kg-1, repeatability for the 20-190 mg/kg contents is 4.0 mg/kg and the yield of the method is 99 %. From interlaboratory cyclic tests of determination of dimetridazol in premixes at the 17-28 g/kg contents, the repeatability index was calculated reaching 5 rel. % and the reproducibility index ranging from 7 to 9 rel. %.