Untargeted Multi-Residue Method for the Simultaneous Determination of 141 Veterinary Drugs and Their Metabolites in Pork by High-Performance Liquid Chromatography Time-of-flight Mass Spectrometry

A rapid, simple and generic analytical method has been developed for the analysis of veterinary drugs in pork by a quadrupole time-of-flight mass spectrometry (Q-TOF MS). This method allows for the simultaneous identification, screening and quantitation of 141 veterinary drug residues and metabolites from eighteen different classes. After extraction with acetonitrile/water and clean-up with C18 cartridges, the samples were analyzed by HPLC-Q-TOF MS. Validation of this method consisted of confirmation of identity, selectivity, linearity, limit of detection (LOD), lowest limit of quantification (LLOQ), matrix effect, recovery, precision and applicability of the method. Identification of the analytes was based on accurate mass measurements. The characteristic fragments were obtained by collisional experiments for a more reliable identification. The procedure was then applied to real pork samples. Sulfamethazine was detected in one sample and its metabolites were successfully found in one single run. This approach proved to be satisfactory for routine analysis.