Optimization Of Mass Spectrometry Determination Methods Of20Forbidden Veterinary Drugs In Swine Samples

There are various kinds of veterinary drugs used for animals, and according to the application can be devided into growth-promoting agents, antibiotics, antiparasitic drugs and sedatives and so on. Majority of those drugs can be easily accumulated in animals’ body and enter into human body through the food chain. Long-term intaking animal products which contain veterinary drugs is seriously harmful to human health. To ensure of food safety, ministry of agriculture announcements in our country stipulates the maximum residue limits of veterinary drugs in animal food, and many drugs such as β-receptor agonists, synthetic hormones, sedatives, nitrofuran, and nitroimidazoles antibiotics should not be detected in animal food. It is imperative to develop a high sensitivity and high resolution detection technology to avoid false positive results.A ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry screening method was established by optimizing the pretreatment methods and chromatography/mass spectrometry facters of20banned veterinary drugs in pork and swine urine; and a quantitative method by high performance liquid chromatography-electrospray ionization-iFunnel-mass spectrometry/mass spectrometry was established for the determination of20forbidden veterinary drugs in swine urine.The main works of this thesis are as follows:1. A UPLC-Q-TOF/MS screening method was established for the simultaneous determination of20forbidden veterinary drugs in pork and urine. Pork samples were extracted by0.1%acetic acid in acetonitrile and purifyed with HLB column. Urine sample was purifyed with HLB column. Blow dry by nitrogen after elution by acetonitrile, constant volume to1ml by acetonitrile-water (v:v=1:9), and then analysis after filtration. The analytes were separated by C18chromatographic column, and detected with positive mass spectrometry ionization mode. The extracted ion chromatogram charts of parent ions were obtained according to accurate mass-to-charge ratio, and according to the chart to establish an external standard quantitative method. According to optimizing of collision induced dissociation (CID)energy, we got product ions accurate mass-to-charge ratio to make qualitative analysis.20compounds showed good linear relationship in the range of5～500μg/L, the linear correlation coefficient were all greater than0.99. The limits of detection (LOD) of20compounds were2-5μ g/L, and the limits of quantitative (LOQ) with pork matrix were5-10g/kg, the limits of quantitative with urine matrix were5-10g/L. At three levels of1,2and4times of LOQ, the average recoverys were64.1%-112.6%, the relative standard deviations (RSD) were3.0%～19.8%. Four kinds of pork samples were detected by this methed and no false positive result was found.2. A HPLC-ESI-iFunnel-MS/MS method was established for the simultaneous determination of20forbidden veterinary drugs in swine urine. The urine matrix was directly purified by HLB solid phase extraction cartridges and then blowed dry by nitrogen after elution by methanol. Constant volume to1ml by acetonitrile-water (1:9,v/v), analysis after filtration. LC analysis was performed on Eclipse Plus C18column. Electro spray ionization was used to analyze these veterinary drugs by using positive ion mode. The iFunnel technology was used to focus ions and Multiple Reaction Monitoring (MRM) was used to monitor ions.Standard curve method was used to quantitative calculation. Under three added level, the average recoveries were81.5%～104.8%, the relative standard deviation was3.0%-16.0%, the limit of detection of the analytes were0.05～0.2μg/L, the limit of quantitative for this method were0.1-0.5μg/L. The HPLC-ESI-iFunnel-MS/MS method of20forbidden veterinary drugs detection in swine urine established in this research has higher sensitivity than traditional methods.The UPLC-Q-TOF/MS screening method can be accurate in qualitative analysis, high resolution and can effectively avoid false positive results; the quantitative method by HPLC-ESI-iFunnel-MS/MS is rapid and sensitive. These two methods that established can reach the requirements of residue detection at home and abroad and provide technical guarantee for food safety monitoring.