Determination of zeranol, taleranol, zearalenone, α- and β-zearalenol in urine and tissue by high-performance liquid chromatography-tandem mass spectrometry

An LC-MS/MS method has been developed for the sensitive determination of the anabolic compound zeranol, its epimer taleranol and the mycotoxins zearalenone, α-zearalenol and β-zearalenol in animal urine and meat samples. Sample preparation included extraction of meat samples and enzymatic digest of urine samples followed by solid phase extraction with RP-18 columns for sample clean-up. Mass spectrometric determination was carried out with an atmospheric pressure chemical ionisation interface (APCI) in the multi-reaction monitoring mode (MRM). Using the negative ion mode, a limit of detection between 0.1 and 0.5 ppb and a limit of determination between 0.5 and 1 ppb could be achieved. With zearalanone (ZAN) as internal standard, a linear range between 0.5 (1.0) and 100 ppb in urine samples (cow, pig) and between 1 and 100 ppb in meat samples (cow, calf, pig) could be established. Depending on the biological matrix and analyte, standard deviations were below 8.5%, with average recovery rates around 86% to 102% in spiked samples. The usefulness of the method developed was demonstrated via several contaminated cow and pig urine samples.