| Veterinary drugs play a very important role in preventing and treating animal diseases,improving production efficiency and optimization the quality of animal products.However,many veterinary drugs tend to remain in animals after usage and enter to the human body via the food chain,even endangering health.Currently,standards for the detection of veterinary drug residues remained in animal derived foods in China are basically categorized by the structure of tested substance.For the same sample it’s necessary to test different types of indicators with different standards are used for repeated inspections that consumes a lot of human,material,financial resources and time costs.In order to economize detection costs,shorten detection cycle and ensure the accuracy and reliability of detection results,this study was based on QuEChERS method,combined with high performance liquid chromatography-tandem mass spectrometry technology（UPLC-MS/MS）,and established a pretreatment technique for veterinary drug residue remained in animal foodstuff.Meanwhile,the matrix effect which influenced the accuracy of the analysis was discussed relative systematic in detail.Finally,effective compensate measures were taken to the influence of matrix effect on the test results,and the method was validated methodologically.The concrete contents of this study were as follows:（1）In this experiment pork was used as the matrix and UPLC-MS/MS as the detection method.The QuEChERS pretreatment technology for the 24 kinds of veterinary drugs was optimized in three aspects:extraction solvent,dehydrating agent and purifying agent.The results have showed 0.1%formic acid acetonitrile（volume percentage）without dehydrating agent and purifying agent was the most suitable as extraction solvent,the average recovery rate was 64.05%87.73%（n=3）.The defined extraction solvent was 0.1%formic acid acetonitrile without purifying agent,3g anhydrous Na2SO4 was the most suitable dehydrating agent for the 24 kinds of veterinary drugs,the average recovery rate was 65.23%104.44%（n=3）.The extraction solvent was defined to 0.1%formic acid acetonitrile with 3g anhydrous Na2SO4 and 2g C18E as purifying agent were the most suitable for 24kinds of veterinary drugs,and the average recovery rate was 60.71%98.14%（n=3）.（2）The matrix effects of the 24 veterinary drugs with using in carp,chicken,duck gizzard,pork liver,beef,and pork was systematically evaluated and refer to the compensation effect on matrix by isotope internal standard and matrix-matched standard curve.The results have showed that the isotope internal standard validation method for matrix effect needs use for sulfamethoxine（SDT）,sulfamethoxine（SDX）,ciprofloxacin（CIP）,enrofloxacin（ENR）,norfloxacin（NOR）,erythromycin（ERY）and amantadine（AMA）.The matrix effect of the seven veterinary drugs were respectively decreased by 0.15%66.94%,（n=3）in the 6 kinds of matrix.The other 17 kinds of veterinary drugs need to use matrix-matched standard curves to validate the influence of matrix effects on the test results.The recovery of the 17 kinds of veterinary drugs was increased by 11.71%59.47%（n=3）after the validation of the blank pork matrix matching standard curve.The interference of its ration results was effectively compensated.（3）The method was evaluated by standard curve and linearity,detection limit and quantitative limit,accuracy and precision and the method was applied to 158 groups of animal foodstuff.The results have showed the 24 kinds of veterinary drugs linear correlation coefficient R≥0.99,the limitations of detection（LODs）of SAs were in the range of 0.125μg/kg5.0μg/kg,the recovery rates were between 71.0%to 111.1%,and the accuracy of（RSDs）reached to 0.9%13.8%.The LODs of QNs were 0.2μg/kg5.0μg/kg,the recovery rate was 70.2%112.7%,and the RSDs were0.7%13.7%.The LODs of MALs were 0.2μg/kg10μg/kg,the recovery rates were 70.4%109.9%,and the RSDs range were 1.4%13.3%.The LODs of antiviral were 0.35μg/kg2.0μg/kg,the recovery rate was 71.7%109.8%,and the RSDs were 1.0%11.0%.The LODs of antiparasite and antagonist were 0.125μg/kg2.0μg/kg,the recovery rate was 70.9%97.8%,and the range of RSDs was 1.2%13.8%.This method was applied to 158 groups of animal foodstuff,the detection rate of CIP was 5.1%,the detection rate of ENR was 24.1%,the unqualified rate was 0.63%,and the detection rate of sulfamethoxine（SMM）was 1.3%.The unqualified rate was 0.63%,and the detection rate of telmicoxin（TIL）was 1.3%,the other 20 veterinary drugs were not detected.In summary,this method had simplified pretreatment process,strong maneuverability,efficient and quick inspection,sensitivity of instruments,high accuracy and low cost,which is suitable for high-throughput detection of veterinary drugs for animal-derived foodstuff. |
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