High-performance liquid chromatographic method for the determination of the dinitrocarbanilide component of nicarbazin in eggs with on-line clean-up.

A high-performance liquid chromatographic method for the determination of the dinitrocarbanilide component of the anti-coccidial drug nicarbazin has been developed. The drug was extracted from egg with acetonitrile. The extract was evaporated to dryness and taken up in water-acetonitrile (80:20, v/v). The extract was then injected onto a reversed-phase precolumn. After clean-up with 20% aqueous acetonitrile for 5 min, the precolumn was eluted onto a Chromspher C18 cartridge column with 0.01 M potassium dihydrogen-phosphate pH 4.0-acetonitrile (50:50, v/v). Detection was by ultraviolet at 343 nm. Average recoveries at five levels from 0.005 to 0.500 mg kg-1 were > 80%. The limit of determination was 0.005 mg kg-1.