Abstract: A molecular imprinting polymer (MIP) using ursolic acid (UA) as template molecule, 4-VP as functional monomer, EGDMA as the cross-linking agent was synthesized on the surface of silica. The interactions between the template molecule and functional monomer via hydrogen-bond and ionic-bond were studied by UV-Vis spectra. The MIP was characterized by IR spectroscopy and SEM. The static adsorption equilibrium experiments and the Scatchard analysis show that there were two kinds of binding sites in the MIP and the dissociation constants were 1.02 x 10-4 mol/L and 8.97 x 10-4 mol/L respectively. The MIP exhibited better adsorption properties and selectivity compared with the corresponding non-imprinted polymers. UA can be enriched effectively by using the MIP as a solid-phase extraction reagent and the enrichment index was 30 times that of oleanolic acid (OA).
Template and target information: ursolic acid, UA
Author keywords: Ursolic acid, Oleanolic acid, surface molecular imprinting, Scatchard analysis, Solid-phase extraction