Simple and rapid determination of triclabendazole and its metabolites in bovine and goat muscle tissue

Triclabendazole (TCB) is widely used for prevention and treatment of parasitic infections in animals. Improper use can result in drug residues in animal tissues and cause health problems to humans through consumption. A simple and reliable analytical method for the determination of TCB and its metabolites in bovine and goat muscle using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. Analytes were extracted using acetonitrile and purified using enhanced matrix removal cartridge. Chromatographic separation was carried out on a BEH Shield RP18 column. The analytes were detected in positive-mode electrospray ionization mass spectrometry using multiple reaction monitoring. Average recoveries of 96.1%-105.6% with coefficients of variation of 1.9%-8.4% were obtained at fortification levels of 0.5, 2.5, 25, and 50 mu g/kg for TCB and 5.0, 25, 250, and 500 mu g/kg for its metabolites (triclabendazole sulfoxide, triclabendazole sulfone, and keto-TCB). A good linear regression was obtained with the mixed standard solutions in the range of 0.05-20 mu g/L for TCB and 0.5-200 mu g/L for its metabolites. The limit of quantification and limit of detection ranged from 0.05 to 0.75 mu g/kg and from 0.1 to 1.5 mu g/kg, respectively. Moreover, this method was successfully applied to 33 real samples.