The Preparation And Application Of Molecularly Imprinted Polymers Of Fenthion

Molecularly imprinted polymers have advantages of high affinity, good specificity and high stability. It is convenient, efficient and has good selectivity when combining MIPs with the solid-phase extraction in the sample purification, enrichment and separation. The fenthion is a popular kind of organophosphorus pesticides (OPs) which is used extensively in agriculture due to its relatively low persistence and easily hydrolyzed, it has been baned in European and other countries. It has good prospects to determine the residue of organophosphorus pesticides.In this paper, molecularly imprinted polymers using fenthion as the template were prepared by suspension polymerization. And the influence of different conditions of synthesis on the adsorption property and the principle of the adsorption were studied. The MIPs were prepared in the optimized conditions. Results showed that the MIPs may get higher selectivity and affinity when using15mL chloroform as solvent．Higher selectivity had also been obtained using MAA as the monomer and EGDMA as the crosslinker, and with the proportion of1:4by template and monomer.Equilibrium rebinding experiments indicated that the adsorption capacity of MIPs for fenthion was better than NIPs. Scatchard plot of analysis revealed that there was two different binding sites in the MIPs with dissociation constants of0.30μg/mL and14.8μg/mL, an apparent maximum binding constant of0.25mg/g and0.51mg/g. It could get homogeneous and porous microspheres by SEM with suspension polymerization. Infrared spectrum studies of the polymers also confirm the existence of the functional groups which may interact with the template. The article also studies the principle, operation process and application. MIPSE is used in the separation and enrichment of fenthion in the tomatoes. Results show that it has high recovery.MIPs prepared with suspension polymerization have high selectivity and affinity to the template. The molecularly imprinted solid-phase extraction combines the advantages of MIT and SPE, and it will have a higher development and wider application in many aspects.