Determination of 16 Kinds of Veterinary Drug Residues in Pork by QuEChERS Coupled with HPLC-MS/MS

A method for the simultaneous determination of 16 veterinary drug residues in pork by using QuEChERS pretreatment combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established. The samples were extracted and purified by using the QuEChERS technology with water −0.1% formic acid acetonitrile, and then analyzed and determined in the positive ion multiple reaction monitoring (MRM) model. The results showed that: there was a good linear relationship among the 16 veterinary drugs in the range of 2.0−100.0 μg·kg⁻¹ (the correlation coefficient r＞0.9970). The limits of determination (LOD, S / N = 3) and limits of quantitation (LOQ, S/N = 10) ranged from 0.01 to 0.25 μg·kg⁻¹ and from 0.03 to 0.82 μg·kg⁻¹, respectively. The spiked experiments at three different concentration levels of 2, 4 and 20 μg·kg⁻¹ were carried out in the pork samples. The relative standard deviation (RSD) ranged from 1.1% to 9.0%, and the recovery rate ranged from 70.4% to 118.1%. The repeatability and recovery rate of the method met the test requirements, and the sensitivity was high, which was suitable for the analysis and detection of various veterinary drug residues in pork.