Rapid Screening And Quantitative Detection Of Veterinary Drug Residues In Animal Derived Food

With the rapid and steady growth of China’s economy,the breeding industry is booming and animal-derived food emerges one after another.Therefore,as common drugs used in the breeding industry,veterinary drugs play a significant role in preventing and treating diseases,increasing production and upholding public health safety.At the same time,the food safety problems caused by veterinary drug residues are attracting greater social concern.Residue limit of veterinary drugs is the criterion to evaluate the safety of animal-derived food,thus it is a vital part in international cooperation and competition.Therefore,it is increasingly important to study the efficient and accurate screening and quantitative detection techniques of veterinary drug residues in food.This research project focuses on the analysis of veterinary drug residues in food of animal origin,and the following studies are carried out:（1）Establish a fully automatic analysis method forβ-receptor agonists in meat products（mainly pork and lamb）by online solid phase extraction-high performance liquid chromatography-tandem mass spectrometry.After being enzymatically digested at 37℃for 16 h,samples were purified by on-line solid phase extraction on an MCX column,and then separated on an XBridge C18 column by gradient elution using 0.1%formic acid solution and acetonitrile as the mobile phase.Mass spectrometric data were acquired under multiple reaction monitoring（MRM）mode using positive ion electrospray ionization.Quantitation was performed by the internal standard method.The results showed a good linear relationship in the concentration range of 0.01–10.00 ng/mL was achieved for all analytes with acorrelation coefficient higher than 0.999 0.The detection limit of the method is 0.004⁰.040μg/kg,and the limit of quantification of the method is 0.02⁰.20μg/kg.The recoveries of the method ranged from 76.5%to 107.7%,with relative standard deviation（RSD）lower than 10%.These results demonstrate that the method is simple,sensitive,and can be used for quantification of 10β-agonists in pork and lamb samples.（2）A rapid method was presented for the determination of 19 quinolone antibiotics in milk by ultra-performance liquid chromatography-quadrupole orbitrap high resolution mass spectrometry.Milk samples were extracted by acidified acetonitrile and purified by PRiME HLB solid phase extraction column,then separated by Waters Acquity BEH C₁₈column（100 mm×2.1 mm,2.5μm）using a binary solvent system composed of acetonitrile and water（0.1%formic acid）by gradient elution.The analytes were determined by quadrupole-orbitrap high resolution mass spectrometry in full-MS and data-dependent scan（ddMS²）mode.The results showed that mass accuracy error of the 19 quinolones were lower than 3.0×10^-6,linear relationships were well in the range of 0.2-200 ng/mL for19 antibiotics,and correlation coefficients were higher than 0.998.The LODs were in the range of 0.1-0.5μg/kg and the LOQs were in the range of 0.2-1.0μg/kg.With spike levels in the range of 0.2-10.0μg/kg,recovery of the method was in range of 62.1%-100.4%and relative standard deviations were lower than 10%.The method is simple,rapid,accurate,which is suitable for the rapid screening and quantitative analysis of 19 kinds of quinolones antibiotics in milk sample.（3）A rapid method was presented for the determination of 9 macrolides antibiotics in pork sample by ultra-performance liquid chromatography-quadrupole orbitrap high resolution mass spectrometry.Pork samples were extracted by acetonitrile and cleaned with n-hexane,then separated by Waters Acquity BEH C18 column（100 mm×2.1 mm,1.7μm）using a binary solvent system composed of methanol and water（0.1%formic acid）by gradient elution.The analytes were determined by quadrupole-orbitrap high resolution mass spectrometry in full-MS and data-dependent scan（ddMS2）mode.The results showed that mass accuracy error of the 9 antibiotics were lower than 1.0×10-6,linear relations are favourable in the range of 0.5-100 ng/mL for 9 antibiotics,and correlation coefficients were higher than 0.998.The LOD is in the range of 0.05-0.2μg/kg and the LOQ is in the range of 0.1-0.4μg/kg.Recovery of the method is in range of69.4%-107.6%with spike levels of 0.1-4.0μg/kg,relative standard deviations were lower than 10%.The method is simple,rapid,accurate,which is suitable for the rapid screening and quantitative analysis of 9 kinds of macrolides antibiotics in pork sample.