A reverse-phase high-performance liquid chromatographic determination of nicarbazin residues in eggs.

A reverse-phase high-performance liquid chromatographic (HPLC) method was employed for analysis of nicarbazin [1:1 mixture of 4,4'-dinitrocarbanilide (DNC) and 2-hydroxy-4, 6-dimethyl-pyrimidine] in chicken eggs. Nicarbazin residues were analysed by determining the DNC of nicarbazin. HPLC of the DNC portion of nicarbazin was performed with a reverse-phase mu-Bondapak C18 column, using a mobile phase of acetonitrile-water (7:3, v/v). A variable-wavelength detector set at 340 nm, 0.02 AUFS, and a recorder set at 4 mm/min were used for the detection. The standard curve for nicarbazin was linear within the range 0.05-2.0 micrograms/ml. The recovery of nicarbazin added to eggs was 90.2%. The detection limit of nicarbazin in this analytical method was 0.005 micrograms/ml. Nicarbazin was detected in 10% of eggs obtained by feeding chickens with a diet contaminated with nicarbazin within the range 0.07 to 1.39 micrograms/g, but it was not detected in eggs obtained commercially.