Research And Application Of QuEChERS Combined LC-MS/MS On Veterinary Drug Residue In Animal-derived Food

Based on QuEChERS method and high performance liquid chromatography-tandem mass spectrometry technology?HPLC-MS/MS?,this paper studied and established the analytical method of veterinary drug residue in aquatic product and livestock products.Meanwhile,the matrix effect which influenced the accuracy of the analysis was discussed in detail.Finally,we also systematically evaluated the uncertainty of residue during the period of determine the 45 kinds of veterinary drug.The specific contents of this thesis are as follows:1.This part mainly summarized the general situation and research progress of veterinary drug residue analysis and illustrated the necessity and urgency to detection routinely the veterinary drug residue in food.What's more,through the comparison between the different methods,technical advantages of high performance liquid chromatography-tandem mass spectrometry were highlighted.2.A analytical method was developed used to detect 45 veterinary drug residues,divided into six kinds,such as sulfonamides,quinolones,tetracyclines,amphenicols,?-adrenergic receptor agonists,Malachite Green and Leucomalachite Green.According to the QuEChERS method,the sample was extracted with 5%formic acid in MeCN and 0.1 mol/L Na2EDTA-Mcllvaine buffer solution,followed by dSPE cleanup with octadecyl silane?C18?and anhydrous magnesium sulfate.Then,the extractive was separated on a Waters CORTECH UPLC C18+?100×2.1 mm,1.6 ?m?column,which was detected by HPLC-MS/MS under the condition of an electrospray ionization?ESI+/-?source in either positive or negative mode and the dynamic multiple reaction monitoring?MRM?mode,so that we can make the simultaneous detection of six categories of veterinary drug residues come true.The results showed that,the calibration curves of 45 veterinary drugs were linear in the range of 0.1?200?g/L,whose correlation coefficients were more than 0.990.The average recoveries of 45 analytes ranged from 74.1%to 116.3%at three different spiked concentration levels?10,50,200 ?g/kg?with satisfactory relative standard deviations which were in the range of 1.6%?9.8%.In addition,the limits of quantitation?LOQ,S/N?10?of nearly 85 percent of veterinary drugs were 8.0 ?g/kg.In a word,the method is highly quick,simple,efficient,safe and can meet the need that determines simultaneously multi-drug residues in the real examples.3.The method analyzed matrix effects and influencing factors of different kinds of veterinary drugs in different animal-derived matrix and different concentration using HPLC-MS/MS.The matrix effects of three different pretreatment methods of purifying were compared to determine the optimal purification methods;A systematical analysis on matrix effects of each drug in different concentration and animal-derived matrix was deal with.The results indicated the pretreatment methods of QuEChERS achieved the best effect in purifying.Most analytes didn't show obvious matrix effect,except part of veterinary drugs.Furthermore,it was influenced by sample matrix,veterinary drug and its concentration,which presented a method reference for how to eliminate or reduce the matrix effect effectively in the actual detection.4.In this section,the uncertainty of 45 kinds of veterinary drug residues in animal-derived products was evaluated by HPLC-MS/MS.A mathematical model was established to analyze and calculate the various factors that influenced accurate quantitative,including preparing of standard solution(u_rel?Cstd?),weighing of sample?Urel????,volume of sample(u_rel?V?),recovery rate(u_rel???)and measurement repeatability(u_rel???).Based on these,the relative combined uncertainty(u_rel?C_x?)was calculated,then the expanded uncertainty was obtained?U?,which provided an important reference to assess the accuracy of test results.The result showed that preparing of standard solution and measurement repeatability were the most critical influencing factors.