Determination Of Pesticide Residues In Vegetables By High Performance Liquid Chromatography Tandem Mass Spectrometry

Pesticides can be used to obtain agricultural harvest,increase the production of agricultural products,prevent and cure crop diseases and insect pests,and play a vital role in agricultural production.However,the improper use of pesticides to cause excessive pesticide residues will affect people's happiness index.In recent years,the abuse of pesticides has led to the excessive standard of pesticide residues in vegetables to cause human and livestock.Reports of poisoning incidents are common.In this regard,in order to strictly control the pesticides in agricultural production and ensure that the people can eat safe and reassurance vegetables on the table,it not only needs the powerful supervision of the relevant government departments,but also needs to support the effective and stable technical methods for the measurement of agricultural residues.The purpose of this thesis is to establish a high performance liquid chromatography mass spectrometry/mass spectrometry(HPLC-MS/MS)method for the determination of residual pesticide residues in different vegetable varieties,to better serve the implementation of pesticide residue limit standards and to better ensure the safety of the tip of the tongue.The specific research process and results are as follows:1.A method for determination of pesticide residues in different vegetables by high performance liquid chromatography tandem mass spectrometry was established.Select five representative varieties of vegetables in nanjing,respectively head cabbage,Chinese cabbage,tomato,cucumber and green beans.Determination of aldicarb,aldicarb sulfone,alicarb sulfoxide,methomyl,acephate,carbendazim,imidacloprid,pyrimethanil,1-naphthalenyl methyl carbamate,carbofuran,carbofuran-3 hydroxy,acetamiprid,pirimicarb,metalaxyl,phoxim,pyridaben,prochloraz,dimethomorph,difenoconazole,abamectin of 20 kinds of pesticide residues in 5 kinds of vegetables.This method is based on QuEChERS.The vegetable samples were directly extracted by acetonitrile,and the sodium chloride was added to the machine directly after the centrifuge was centrifuged by the sodium chloride.The positive ion multi reaction monitoring model was used and the external standard method was used to quantify the sample.The 20 detection limits of carbendazim were 0.0005mg/kg?0.005mg/kg.2.The method of determination of high performance liquid chromatography tandem mass spectrometry in different vegetables was verified.This chapter on the basis of the latest biggest pesticide residues in food by limited standard GB/T 2763-2016.Add 0.0016mg/kg,0.064mg/kg,0.24mg/kg of three levels to the head cabbage,Chinese cabbage,tomato,cucumber and green beans.According to the preprocessing and instrument method described in the first chapter,the recovery rate and precision of 20 kinds of pesticides,such as carbendazim,in 5 kinds of vegetables,such as Chinese cabbage,were determined.The mixed standard solution of 20 kinds of pesticide residues was prepared by cucumber matrix.The results showed that the average standard recovery of 20 kinds of pesticide residues in Chinese cabbage was 71.4%?118%.The average relative standard deviation was 1.25%?17.6%,the average standard recovery of 20 kinds of pesticide residues in cabbage was 72.9%?112%,The average relative standard deviation was 1.03%?14.9%,The cucumder is 70.8%?119%,the average relative standard deviation is 1.13%?14.6%,and the average standard recovery in Green beans is 70.0%?104%,the average relative standard deviation is 2.20%?15.7%,and the average recovery rate is 77.3%?105%and the average relative standard deviation is 1.98%?16.3%in tomatoes.This method is fast,simple and sensitive.It can be used for the rapid detection of 20 kinds of pesticide residues in 5 vegetables such as Chinese cabbage,which provides a strong guarantee for the risk assessment of vegetable quality safety.3.The application and prospect of high performance liquid chromatography-tandem mass spectrometry for the determination of residues in vegetables.Five kinds of representative vegetables in Nanjing were selected,and the method of HPLC-MS/MS was used to determine the residual pesticide residues in Nanjing City.The test of Chinese cabbage,cabbage,cucumber,four season beans and tomatoes was carried out in Gaochun District,Lishui District,Qixia District,Jianye District,Liuhe District,Yuhua District,Pukou area and Jiangning area.Through one year monitoring and tracking.In one year,the Gaochun District detected carbendazim,imidacloprid,imidamamine,pyridamoximine,dimethocyclozole,metalaxyl,acetamiprid.In the year of Lishui,we detected carbendazim,imidacloprid,imidamidine,pyridamine,dimethocyclozole,enoylmorpholine,pyridazine,and dipyridamole were detected in only second of the year of Qixia,and metazolazole were detected in the third quarter.In the year of Jiangning,carbendazim,methanw,imipramine,pyridamine,acetamidophos,dimetheazolazole,metalaxine,acetamiprid were detected.Yuhua,Jianye,Liuhe and Pukou were not detected.Although pesticide residues in Gaochun,Lishui,Qixia and Jiangning have been detected,there are certain differences in pesticide residues in different regions,but according to the maximum pesticide residues in vegetables,all the pesticides mentioned above are not exceeding the standard.In summary,the dosage of pesticides in each region of Nanjing is still relatively standard.Vegetable varieties are relatively safe,although some areas have detected carbendazim,imidacloprid,acetamiprid,pyridamidine,enoylmorpholine,diphenocyclozole and other pesticides,but not beyond the state's maximum residue limit standard,the overall situation is well controlled.It can not only meet the large quantity of sample,but also use less time,high accuracy,precision and sensitivity all meet the pesticide residue detection and analysis,which has strong practical significance and application value.