Determination of veterinary drugs in foods of animal origin by QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

A method using QuEChERS coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of the residues of 19 veterinary drugs in ten animal-derived matrices, including beef, pork, sheep, horse, chicken, prawn, fish, liver, milk, and fat. This method was based on the enactment of veterinary drug compounds by Korea, Canada, the United States, and the European Union in recent years. The samples were extracted using 85% acetonitrile and separated on an ACQUITY UPLC HSS T3 column (2.1 mm × 100 mm, 1.8 μm) with a gradient elution of methanol-0.2% formic acid water as the mobile phase. The detection of the analytes was achieved through the use of positive ion electrospray ionization (ESI) and multiple reaction monitoring (MRM) modes, while the quantification was conducted via the matrix-matched external standard method. Following optimization, the linearity of the target veterinary residues in the ten matrices was observed to be satisfactory, having a range of 0.5-50.0 ng/mL (R > 0.991). The limits of detection (LOD) were in the range of 0.01-1.29 μg/kg, while the limits of quantification (LOQ) were in the range of 0.02-4.31 μg/kg. The recoveries were observed to be in the range of 60.6-117.7 %, with relative standard deviations (RSDs) of ≤20.6 %. The method is straightforward and highly sensitive, and it satisfies the maximum limits set by the relevant standards of Korea, Canada, the USA, and the EU. It is well-suited for the rapid screening, qualitative, and quantitative analyses of metomidate, acetanilide, dl-methylephedrine, and other substances in foods of animal origin, providing technical assistance for cross-border food safety and testing.