Simultaneous Determination of Residues of 46 Veterinary Drugs in Livestock and Poultry Meat by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry with One-Step Purification of Solid Phase Extraction

A method for simultaneous determination of residues of 46 veterinary drugs in livestock and poultry meat, including sulfonamides, quinolones, macrolides and benzimidazoles, was proposed by ultra-high performance liquid chromatography-tandem mass spectrometry with one-step purification of solid phase extraction. The sample was extracted with acetonitrile by oscillation, and then repeatedly degreased by n-hexane. The obtained solution was purified by one-step purification with SHIMSEN Qvet-NM solid phase extraction column. The purified sample was separated by ZORBAX Eclipse Plus C₁₈ column, using the mixture of 0.1%(volume fraction) formic acid solution and acetonitrile at different volume ratios as the mobile phase for gradient elution. Multiple reaction monitoring mode of tandem mass spectrometry was adopted, with internal standard method for quantitative analysis. As shown by the results, linear relationships between values of mass concentration and peak area ratio of target to internal standard were found in definite ranges, with detection limits (3S/N) of 0.1 μg·kg^-1 for sulfonamides and quinolones and detection limits (3S/N) of 0.5 μg·kg^-1 for macrolides and benzimidazoles. The detection limits were far lower than the limits of veterinary drug residues in meat products set by the European Union (except for prohibited veterinary drugs). Test for recovery was made by standard addition method, giving results in the range of 72.9%-110%, with RSDs (n=6) of the determined values less than 15%.