Liquid chromatographic determination of nicarbazin in feeds and premixes

A liquid chromatographic (LC) method has been developed for the determination of nicarbazin in premixes and poultry feed. Liquid chromatography of the 4,4'-dinitrocarbanilide (DNC) portion of nicarbazin is performed isocratically with a reverse phase octadecylsilica column and a UV detector set at 340 nm. The 2-hydroxy-4,6-dimethylpyrimidine (HDP) portion of nicarbazin is chromatographed isocratically with a reverse phase octylsilica column and a UV detector set at 305 nm. Nicarbazin concentration can be calculated by assaying both DNC and HDP, or by assaying DNC or HDP and assuming that nicarbazin is a 1:1 molar ratio of the two. Average recoveries of DNC and HDP added to poultry feed were 101% and 87%, respectively. This procedure provides an alternative to existing colorimetric procedures for determining nicarbazin in premixes and poultry feeds.