Simultaneous determination of multiveterinary drug residues in pork meat by liquid chromatography-tandem mass spectrometry combined with solid phase extraction.

An LC-MS/MS method developed for simultaneous analysis of 54 veterinary drug residues of six families in pork meat samples, including sulfanilamide, nitroimidazoles, quinolones, macrolide antibiotics, lincosamides, and praziquantel. The pork meat sample was prepared by extraction with ACN, and clean-up on a C(18) SPE cartridge. The sample was separated on a C(8) column and eluted with ACN, methanol, and formic acid. The MS/MS detector is operated in the multiple reaction monitoring mode, acquiring two specific precursor-product ion transitions per target compound. The method showed excellent linearity (R(2) ≥ 0.99) and high precision (relative SD, RSD ≤ 19.8%) for all compounds. The method quantification limits of 54 veterinary drug residues were in the range of 0.3-3.0 μg/kg. Recoveries for most analytes based on matrix-matched calibration in matrices were 20.9-121.0%. This method has been successfully applied for analysis of more than 100 pork meat samples from the local market; five of the 54 drugs were detected.