Synthesis Of Gallic Acid Molecular Imprinted Polymer And Its Molecular Recognition Function

Traditional methods for qualitative or quantitative analysis of gallic acid have been limited by the drawbacks such as complex operation,time-consuming with poor sensitivity and selectivity.In this paper,novel molecular imprinting technique was applied in the detection of gallic acid.Gallic acid molecularly imprinted polymer(GAMIP)was prepared as solid phase extraction adsorption material due to its advantages of good environmental tolerance,simple preparation,low cost,high selectivity and chemical stable properties.The research and finding in this work may provide a new approach for the rapid detection of gallic acid.Firstly,the optimal functional monomers and crosslinking agent was selected by molecular simulation with Materials Studio 7.0.Then ultraviolet spectrophotometry was utilized for the determination of the mole ratio between gallic acid(template molecule)and functional monomer.To optimize the preparation conditions of gallic acid molecularly imprinted polymer(GAMIP),adsorption performance of molecularly imprinted polymers(MIPs)was studied,which were synthesized by different functional monomer,crosslinking agent,solvent and mole ratio between the template and monomer.Furthermore,isothermal adsorption,dynamic adsorption experiments as well as Scatchard analysis of the as-prepared GAMIPs were investigated,respectively.At the same time,the identification characteristics of GAMIPs were also studied.In addition,the structures of blank polymer and imprinted polymer before and after extraction and after adsorption were characterized by infrared spectrum,respectively.And the appearance of blank polymer and imprinted polymer was characterized by scanning electron microscopy(SEM).It is suggested by the simulation results of Materials Studio 7.0 that the optimal functional monomer and crosslinking agent are 4-vinylpyridine and EDMA respectively for the synthesis of GAMIPs.The GAMIPs with the best adsorption performance was synthesized by using gallic acid as template molecule,4-vinylpyridine as functional monomer(gallic acid: 4-vinylpyridine = 1:4,mole ratio),EDMA as cross-linking agent and acetonitrile as solvent,which has a good agreement with the results obtained by computer simulation.The isothermal adsorption curve and Scatchard curve indicate that there are three different binding sites in GAMIPs.The identification experiment shows that the as-prepared GAMIP has good specificity for gallic acid,which was further proved by infrared spectroscopy.Scanning electron microscopy(SEM)shows that GAMIP has highly cross-linked microporous with loose structure and large surface area.