Multi-residue Determination Of Veterinary Drugs In Cheese By Liquid Chromatography-Tandem Mass Spectrometry

Veterinary drugs have been widely used in the field of animal husbandry. Accompanied by the issue of food safety, the problem of veterinary drug residues in food has drawn lots of attention in recent years. This article made a brief overview of different classes veterinary drug, such as macrolides, sulfonamides, quinolones, teracyclines, etc, and assessed the monitoring situation of veterinary drugs.A comprehensive review for the methods and technologies of detecting the veterinary drugs was presented, included the sample pretreatment and the determination process.For instance, this article reviewed the principles and operation procedures of liquid-liquid extraction, solid phase extraction, QuEChERS(Quick, Easy, Cheap, Effectiv, RuggedandSafe), gel performance chromatography, immunoaffinity chromatography and accelerated solvent extraction, and this article also outlined the determinationmeasures of high performance liquid chromatography, liquid chromatography trandem mass spectrometry, liquid chromatography quadrupole time of flight mass spectrometry, capillary electrophoresis, Enzyme linked immunosorbent assay, etc.A rapid and sensitive method has been developed for simultaneous determination of 50 veterinary drugs(including macrolides, quinolones, sulfonamides, and tetracyclines) in cheese using a modified QuEChERS method coupled with liquid chromatography-tandem mass spectrometry. After adding Na2 EDTA buffer solution and ceramic homogenizer, the cheese sample was extracted by 5% acetic acid-acetonitrile, sodium chloride and anhydrous sodium sulfate were used for salting-out process. The resulting supernatant solution was purified by C18 sorbent and the re-dissolved solution was analyzed by LC-MS/MS under dynamic multi-reaction monitoring(dynamic MRM) mode. The limits of quantification(LOQ, S/N = 10) of the target compounds ranged from 0.05 μg/kg to 20 μg/kg in cheese. At three spiked levels(n = 6), the percentage of drugs with a recovery between 70% and 120% was 94%, 92%, and 96%, respectively. The relative standard deviations(RSD) were between 1% and 14%. This method has been applied to determine 7 real samples from markets, roxithromycin and flumequine have been detected in two samples respectively. This simple, rapid and accurate method is suitable for detection of multi-class veterinary drugs in cheese.