Study On On-Line Extraction Of Organic Pesticide Based On Polymerized Ionic Liquid Functionalized Magnetic Particles

The greater demand of human society for agricultural products with good quality and stable supply is,the more organic pesticides are used in agricultural.But the organic pesticides could lead to sustained and far-reaching harm in nature,so it is urgent to detect the content of organic pesticides in environmental samples.In this paper,the ionic liquids(ILs),which have shown excellent characteristics in sample pretreatment,was immobilized on the surface of magnetic materials to prepare the poly(ILs)functionalized magnetic particles adsorbent(PILs-MPs).In addition,an on-line magnetic solid-phase extraction device was constructed to detect organic pesticides in environmental samples,from which good results were obtained.This work mainly studies from the following two aspects.The polymerized vinyl ionic liquid[VBIm]NTf2 was modified on the surface of the thiol-functionalized Fe3O4 by the "thiol-ene" click reaction.The prepared PILs-MPs(NTf2)were used as the magnetic adsorbents in magnetic solid-phase extraction(MSPE)for analyzing pyrethriod pesticides in environmental samples,prior to GC-MS determination.Important extraction parameters and chromatographic conditions were both optimized.Under the suitable conditions,the proposed method showed satisfactory linearity(correlation coefficients>0.9992)and good reproducibility(RSD<6.2%,n=6).And the limit of detection(LOD,S/N=3)was 0.06-0.13?g/L for the four pyrethroid pesticides.The method was successfully applied to determine four pyrethroid pesticides from three real samples,and two analytes were detected in the un-spiked samples.The relative recoveries of four analytes were in the range of 85.7%and 110.4%.The good experimental results prove that the developed method is feasible for real environmental sample.Fe3O4 was modified with vinyl-silanization reagent(VTEO),and then[VBIm]Br was immobilized by radical polymerization reaction between vinyl groups to prepared PILs-MPs(Br)magnetic adsorbent.Besides,an on-line MSPE device based on fluidized bed was constructed,which improved the operation efficiency and reduced the human error.The application of PILs-MPs(Br)and the MSPE device results in a good extraction effect for five neonicotinoid pesticides(absolute recoveries in the range of 44.02%and 75.19%).It has also opened a path for the on-line MSPE of organic pesticides.