Analysis of veterinary drug- and pesticide residues in pig muscle by LC-QTOF-MS

A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method for screening, quantification and identification of veterinary drugs (antibiotics, nonsteroidal anti-inflammatory drugs, anthelmintics, cocci-diostatics and tranquilizers) and pesticide residues was validated in pig (porcine) muscle. Tissues were extracted with acidic methanol/water with EDTA, followed by dispersive solid phase extraction to remove unpolar interferences. Before analysis the extracts were centrifuged at high speed (12.000 g). A MaXis Q-TOF mass spectrometer equipped with an electrospray ion source was operated in positive mode. In the same analysis full scan acquisition with a mass range of 80-1100 amu and broadband collision induced dissociation (bbCID) acquisition were applied for screening and identification. Identification criteria for screening were established for detector response (intensity and area), mass accuracy, isotopic pattern, retentiontime and qualifier ions. The screening method was validated for 65 veterinary drug residues and 97 pesticide residues and the stability of selected veterinary drugs in pig muscle was evaluated over a six month period.