Study On The Application Of Online Clean-up-liquid Chromatography-tandem Mass Spectrumetry On The Determination Of Common-used Pesticides Residues In Complex Samples

Hunger breeds discontent,and food is the material foundation to the survival of humans;Food safty comes first,and is a pro-people project about national economy and people's livelihood.The problems of pesticide residue seriously affect the food safety.The poisonousness from pesticide residue takes terrible damage to human health and ecological environment.As people's attention emphasis on health and environment,Pesticide residue problems caused the focus of concern to people.So,Goveronments and international organizations attach great importance to implement rigorous planing and monitoring of pesticide residue.At present,The detection methods of pesticide residue in tea and Chinese herbals whose samples' matrixs are complex usually need complex and time-consuming pretreatment processes.Therefore,it is very important to set up a simple,fast and accuracy method to detect the pesticide residues of complex matrix samples.Online purification technology,which combine with the theory of proliferation,chemical and volume exclusion,when capture the interesting analyte,also rapidly eliminate the matrix interference content.It comes true the instrumental analysis clean up full-automatic.It makes the pretreatment process of complex samples simpler,faster and more efficient and becomes a hot issue in the pretreatment techniques of food,biological and other research areas.The study select complex matrix samples(tea,chrysanthemum,honeysuckle),and establish their analytical methods of online clean up-liquid chromatogram-tandemmass spectrum for five neonicotinoid pesticides,nine chloroacetanilide herbicides and ten benzoylurea insecticides.After rehydrated,extracted with acetonitrile,and cleaned-up online,the separation was performed on C18 column with gradient elution,monitored by multiple-reaction monitoring and determined by tandem mass.The results indicated that the limits of quantification for thiacloprid and thiamethoxam in chrysanthemum were 20 ?g/kg,and the limits of quantification for imidacloprid,acetamiprid,clothianidin in chrysanthemum and three kinds pesticides in tea and honeysuckle were 10 ?g/kg.The calibration curves were linear in the range.The spiked recoveries were in the range of 63.6%-123% with relative standard deviations between 2.2% and 18%.The methods were simple,rapid,accurate,and were suitable for the determinations of five neonicotinoid pesticides,nine chloroacetanilide herbicides and ten benzoylurea insecticides in complex matrix samples(tea,chrysanthemum,honeysuckle).