Determination of ochratoxin A in bile of swine by high-performance liquid chromatography

Natural occurence of the nephrotoxic, teratogenic, carcinogenic and immunosuppressive mycotoxin Ochratoxin A (OA) in food and feedstuffs is widespread. Transfer of OA from contaminated feedstuffs to various compartments in pigs and corresponding residues of the toxin in food products from slaughter pigs have been described by several authors. The aim of this study was to develop a sensitive method for the determination of OA in bile, which would make it possible to examine biliary elimination in pigs fed with feedstuffs contaminated to the low degree naturally occurring in Germany. The method consists of extraction with acidified chloroform and purification on a sili-cagel cartridge, followed by liquid-liquid partition. OA was determined by high-performance liqid chromatography with fluorescence detection. The detection limit was 0,3 ng/ml, the mean recovery was 84 %. An enzyme-linked immunosorbend assay proved to be suitable for confirmation of positive results. Because of the low detection limit, biliary elimination of OA in pigs fed with low-contaminated feedstuffs can be examined by this method. This is an important requirement for the study of pharmacokinetic profiles of OA.