Simultaneous Determination of Triclabendazole and its Metabolites in Bovine and Goat Fat Tissues by Liquid Chromatography–Tandem Mass Spectrometry

A sensitive and reliable method for the simultaneous determination of triclabendazole, its main metabolites (triclabendazole sulfone and triclabendazole sulfoxide) and a marker residue (ketotriclabendazole) in edible ruminant fat tissues is developed and validated. Analytes are extracted from fat tissues with acetonitrile, and crude extracts are subjected to liquid–liquid extraction with n-hexane. Chromatographic separation is performed on a C18 reversed-phase column with gradient elution. Analytes are detected by tandem quadrupole mass spectrometry after positive electrospray ionization by multiple reaction monitoring. Relative recoveries from spiked samples range from 86.1% to 114.3%, with relative standard deviations generally below 13.8%. Limits of detection and quantification for analytes are within 0.125–1.25 μg/kg and 0.5–5 μg/kg, respectively. The method proposed in this study was successfully applied to real sample testing.