The determination of the coccidiostat nicarbazin in animal tissue and eggs. I. Determination by pulse polarography and high pressure fluid chromatography with electrochemical detection

The determination of nicarbazin residues in foodstuffs of animal origin by two different methods, polarography, HPLC with electrochemical detection, is described. By applying pulse polarography at the dropping mercury electrode to acetonitrile extracts of animal tissues and eggs, a detection limit of 50 micrograms/kg and mean recoveries of 79% were obtained. The same extracts were used for the HPLC determination with electrochemical detection. This led to a detection limit of 1 microgram/kg. Additional rapid confirmation can be obtained from HPLC using an internal standard (nifursol) and comparing peak area proportions of both substances at varied polarization voltages. The quantitative determination of nicarbazin in chicken eggs by both polarography and HPLC was found to be in good agreement.