Study On Preparation Of Molecularly Imprinted Materials And Solid Phase Extraction Performance

Molecularly imprinted solid phase extraction(MISPE)is a new solid phase extraction technique which using molecularly imprinted polymers(MIPs)as fillers of solid phase extraction column,MIPs own strong specific adsorption capacity and simple preparation method,we used solid phase extraction techniques to pretreat the samples with a complex system so as to achieve the effect of sample purification.Currently,MISPE technology has shown a good application prospect in the actual sample pretreatment before Chromatographic detection,and we have completed a lot of research and improvement work about this technology in recent years.In this paper,Quercetin and Epicatechin were used as template molecules to prepare the MIPs with selective adsorption capacity.The template recovery of MISPE column was tested by CE,meanwhile,we investigated the influences of extraction performance after doping with nanomaterials which have been functionalized.The main contents and results are as follows:1.Molecular imprinted polymers(MIPs)were synthesized by situ polymerization in pipette tip,we studied the polymer in depth.Firstly,the prepared imprinted polymeric materials were characterized by scanning electron microscopy(SEM)and fourier transform infrared spectroscopy(FTIR);then we examined the effect of different ratios of component on the template recovery of MISPE column by CE;finally,we evaluated its application effect in the actual sample(Mangosteen)by chromatographic pre-treatment.Experimental results show,Molecularly imprinted polymers have been successfully polymerized and owned good morphology,under the optimal ratio,the recovery rate of the template molecule of MISPE column can reach 84.12 %,in the actual sample detection study,MISPE treatment can be a good way to removal interference from mangosteen in chromatographic detection.2.Molecular imprinted polymers(MIPs)were synthesized by situ polymerization in pipette tip,using Epicatechin as the template molecule,acrylamide as functional monomer,ethylene glycol methacrylate(EGDMA)as crosslinking agent.Firstly,the selective adsorption properties of epicatechin MIPs prepared by different ratio were investigated,we also characterized MIPs by SEM and FTIR;then we investigated the content of the components in the elution solution of each stage by CE;finally,we established MISPE-CE combined technology to detect the content of epicatechin molecule in actual sample(Six fort tea).The results showed that when the molar ratio of Epicatechin,acrylamide and ethylene glycol methacrylate is 1:6:40,molecularly imprinted polymers own the best adsorption effect,good morphology and specific adsorption properties,meanwhile the template molecular recovery rate can reach 84.62 %,this method also has a very good effect in the actual sample detection.3.Firstly,we used chemical and physical combination modified method to manufacture Hydroxyl functionalized Multi-walled carbon nanotubes(H-MWNTs),the morphological and structural characterization of the products were characterized by SEM,FTIR and Raman spectroscopy;then we prepared Quercetin MISPE column doped with H-MWNTs by situ polymerization;finally,the effect of the addition of H-MWNTs on the extraction performance of MISPE was evaluated by CE.Experimental results showed,we successfully manufacture H-MWNTs by this method.The new MISPE column still own strong imprinting molecular retention performance,because of the addition of nanomaterials,the elution time during MISPE was greatly shortened,it makes the whole experiment more simple and quick with no effect on the experimental results.