Qualitative Screening Of Veterinary Drug Residues In Animal-derived Food Using High Resolution Mass Spectrometry And Instrument Comparison

With the improvement of living standard,dairy products,chicken and egg become an important source of intaking protein for us.Safety of animal-derived foods have drawn our attention because of veterinary drugs residues.If intake unsafety food long term,the risk of suffering the side effects brought by veterinary drugs will increase,like allergy and even cause cancer.Establish a screening method for veterinary drugs residues in animal-derived foods is necessary.From another perspective,a good method is also helpful for regulator to supervise use of veterinary drugs by users.The main works in this paper was as follows:(1)Set up a database covered 120 kinds of veterinary drugs,including precursor mass,retention time,fragment and adducted.Comparison of five chromatography columns,finally choose BEH C18 for better separation efficiency and higher peak area.Set screening target concentration(STC)for each veterinary drug.(2)Study on the exist of protein in matrix whether lead to effect on mass tolerance in HRMS,using normal milk powder and hydrolysis milk powder(without protein)as matrix.As shown on chromatogram of two sample,the mass tolerance of some veterinary drugs should be extended to 20 ppm rather than 5ppm.On the basis of the study before,the efficiency of three clean-up methods(QuEChERS,Prime HLB and EMR-Lipid)has been compared.In milk,compared with Prime HLB and EMR-lipid,QuEChERS has 88 kinds of veterinary drugs getting highest absolute recovery and RSD of 94 kinds of veterinary drugs less than 30%,in chicken and egg were same result.Finally,QuEChERS was set for clean-up method in milk,chicken and egg.(3)This chapter has finished method validation in HRMS by analyzed 60 samples(20 milk,20 chicken,20 egg).When FN/FP≤5% and set 0.2 as cut-off value,103 kinds veterinary drugs in egg were successfully pass through,for milk and chicken,there are respectively 99 and 98 kinds of veterinary drugs pass through.Meanwhile,the same sample after extracting and cleaning up has been analyzed by UPLC-QqQ/MS at same chromatography condition,the analysis result of two detectors were compared and evaluated.Veterinary drugs analyzed by UPLC-QqQ/MS are more prone to show false positive than UPLC-HRMS,the reason probably is the different of resolution and sensitivities.