Simultaneous Determination of Major Antibiotics Veterinary Drug Residues in Pork by UHPLC-Q-TOF/MS

A method for simultaneous determination of 10 veterinary antibiotics residues in pork by QuEChERS purification combined with ultra performance liquid chromatography tandem quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF/MS) was developed. The sample was extracted and purified by Na₂EDTA-Mcllvaine buffer solution-0.1% formic acid acetonitrile-NaCl-anhydrous Na₂SO₄-C₁₈. The separation was performed on an Infinity Lab Poroshell 120 EC-C₁₈ column and analyzed under the positive ion multi-reaction monitoring mode. The results showed that the correlation coefficients of 10 veterinary drugs were greater than 0.99, and the linear range was 5.0~100.0 μg/kg. The average recoveries were 72.3%~117.3% at the spiked levels of 5, 10, 20 μg/kg. The intra-day relative standard deviations (RSD) was 0.9% to 10.4%, and the within-day RSD was 1.1% to 13.4%. The limit of detection (LOD) was 0.25~1.0 μg/kg, and the limit of quantification (LOQ) was 0.5~5 μg/kg. This method was used to detect 50 fresh raw pork samples purchased in the market. One sample was positive for tetracycline, and none of the other samples were detected. The method was simple and fast to operate, had good precision and limit of quantification, and was suitable for the rapid detection of 10 antibiotic veterinary drugs in pork.