Rapid Determination Of Multi-pesticide Residues In Vegetables And Fruits By Chromatography With QuEChERS

The problem of pesticide residues in vegetables and fruits has always been an important aspect offood safety and quality.The sample pretreatment is one of the most important parts in the pesticideresidues detection process. In the sample pretreatment, we not only need to separate target componentsfrom complex matrix effectively, remove interferent from the extraction solvent, but also to enrich lowconcentration components to improve the sensitivity.Compared with the traditional samplepretreatments such as solid phase extraction(SPE), liquid-liquid extraction(LLE) etc, new sampletechnology developed in recent years,such an QuEChERS (Quick,Easy,Cheap,Effective,Rugged,Safty)and DLLME-SFO(Dispersive Liquid-Liquid Micro Extraction based on Solidification of FloatingOrganic drop).For the advantages of simple operation, less reagent consuming, low cost etc, theexperiment meet with the development trend of the rapid analysis of pesticide residues.By reviewing the relevant native or foreign literature and the analysis of a large number ofexperimental data,This paper mainly introduces the related research work in the following four chapters.1. It describes the traditional and new analytic methods of pesticides residues, then introduces thedevelopment and application of DLLME-SFO in food safety analysis,at last the principle anddevelopment of QuEChER is described.2. An analytical method was developed for the determination of114pesticides includingorganophosphor pesticides/chlorine pesticides and pyrethroids residues in vegetables and fruits usingQuEChERS cleanup and gas chromatography(GC) commonly used by Local detection mechanism. thefactors that influence the experimental result were optimized, such as the extract solvent,the additionorder of anhydrous Magnesium sulfate, the application amount of purifying agent etc.the methodImproves the pesticides extraction efficiency and the method reproducibility,and provides a simple,rapid pesticide multi residue analytical method for the county detection mechanism.3. A dispersive liquid–liquid microextraction based on solidification of floating organic dropletmethod (DLLME-SFO) combined with QuEChERS was developed for the determination of sixpyrethroids in vegetables and fruits with gas chromatography. The method uses QuEChERS to extractand purifing the sample,then apply DLLME-SFO on the sample concentration,the experiment greatlyimproves the sensitivity of the method.4. We developed a method for analysising7kinds of pesticides using QuEChERS combined withliquid chromatogram commonly used by local detection mechanism.The test optimizes conditions onthree aspects-the sample solution pH, dehydration agent, the solvent,the developed method provides asimple, rapid pesticide multi residue analytical method for the county detection mechanism.