Synthesis And Application Of Molecularly Imprinted Polymers For Recognition Of Ephedrine

Molecular imprinting technology(MIT)is a rapidly developing technique for the preparation of polymers having specific molecular recognition properties for a given compound. With recognition ability for the template molecule, molecularly imprinted polymer (MIP) is able to selectively extract analyte from complex samples and are growing of interest for their potential applications as advanced materials for solid-phase extraction.In this paper, A molecularly imprinted co-polymer(MIP) with special molecule recognition properties of ephedrine was prepared by self-made water-solubility resin and ephedrine as template molecule. The self-made resin as the adsorbent, We done Equilibrium binding adsorption and solid-phase extraction to the ephedrine and its chiral symmetric. Elution solvent polarity using three different reagents: chloroform, acetone, water.The results showed that:in the copolymer resin,there were the new cavitis which had the same spatial configuration with ephedrine molecule, and ephedrine could be adsorbed by the new cavitis. The sample molecules ephedrine which were adsorbed could be effectively washed out by three kinds of eluants, and the acetone elution best, water second, followed by chloroform. Thus we determined that the effect of molecular imprinting cavitis and the sample molecule was non-covalent bond and physical adsorption.This molecularly imprinted polymer adsorpted both the ephedrine and protonated ephedrine,and the non-imprinted polymer (NIP)also could adsorpt the ephedrine.Then we did the check experiment using pseudo-ephedrine.We found that the adsorption rate of imprinted resin for ephedrine was as high as 95.12 %, but it was only13.38 % for pseudo-ephedrine.This further confirmed that the imprinted holes exist in the resin. This feature of MIPs resins could be used to the chiral separation of ephedrine and pseudo-ephedrine. Then we done the application test: solid-phase adsorption extraction the ephedrine in ephedra extract,and the self-made imprinted resin as solid phase adsorption material. Extraction results with the conventional liquid-liquid extraction were compared, The results showed that this imprinted resins had a selective adsorption on ephedrine and the contents of ephedrine obtained by MISPE was 1.3 times to that obtained by liquid–liquid extraction.