Determination of zearalenone, deoxynivalenol and metabolites in bile of piglets fed diets with graded levels of Fusarium toxin contaminated maize

For the simultaneous determination of zearalenone (ZEA), deoxynivalenol (DON) and their metabolites α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL) and de-epoxydeoxynivalenol (DOM) in bile of piglets, a liquid chromatography with tandem mass spectrometry method including sample preparation with combined immunoaffinity columns (DZT MS-Prep®) has been developed. The analyte concentrations were determined by the use of isotopically labelled internal standards. The mean recoveries for all analytes ranged between 80 and 99%. The determined limits of detection and quantification ranged from 0.01-0.60 and 0.04-2.0 ng/ml, respectively. ZEA, DON and their metabolites were analysed in bile of female piglets fed diets containing 0.01/0.03, 0.05/0.59, 0.08/1.27, 0.17/2.01 and 0.29/4.52 mg ZEA/DON per kg during 29 days of treatment. After 1, 3, 8, 15, 22 and 29 days four piglets per group were slaughtered. ZEA, α-ZOL, β-ZOL, DON and DOM were quantified in almost all bile samples, whereas ZAN, α-ZAL and β-ZAL could only be quantified sporadically. Moreover, dose- and time-dependent effects were observed for most analytes. The toxin residues in bile correlated well with the respective mycotoxin intake per kg body weight and day and the mother toxin concentration in the diets. Due to these high correlations the exposure to dietary ZEA and DON could be predicted by the use of the corresponding regression equations. Strictly speaking these relationships are only valid for the experimental conditions of the underlying experiment. Furthermore, for practical application the individual variation need to be additionally considered.