LIQUID-CHROMATOGRAPHIC DETERMINATION OF NIFURSOL IN CONCENTRATES, PREMIXES, AND FINISHED TURKEY FEEDS

A specific liquid chromatographic method was developed for determination of nifursol in premixes and turkey feeds. Nifursol is extracted from test sample into tetrahydrofuran. Butylhydroxytoluene is added to prevent degradation of nifursol. The extract is diluted with tetrahydrofuran-water (50 + 50, v/v); an aliquot is injected onto a Zorbax ODS column. The mobile phase is water-acetonitrile (525 + 475, v/v) adjusted to an apparent pH of 3.5 with formic acid and ammonia. The wavelength of detection is 380 nm. The system can separate nifursol from dimetridazole and ronidazole. The method is specific; has linearity of more than one order of magnitude; and has a limit of quantitation in the 1-2 ppm range. Recovery averaged 98% or more, and the reproducibility had a coefficient of variation of better than 2.5% in pelleted feed.