Determination of benzimidazole anthelmintics in meat samples.

A procedure for the detection of eight benzimidazole anthelmintics in meat samples using high-performance liquid chromatography is described. The limits of detection are in the range 20-50 micrograms/kg with a recovery of 66-87%. Chromatography is performed on an octadecylsilane column using mobile phases of acetonitrile-water with an ion-pair reagent, with UV detection. For verification of positive results, the drug substances are derivatized to methyl or pentafluorobenzyl derivatives suitable for detection by gas chromatography-mass spectrometry in the electron-impact or positive or negative chemical-ionization mode.