Preparation of Quercetin-Ni<sup>+2</sup> Metal-Complexing Imprinted Polymer and its Recognition Performance Evaluation

Abstract

Using the complex of quercetin and Ni+2 (quercetin-Ni+2) as template (quercetin is a kind of flavonoids which are important active ingredients of Chinese herbs.), methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker, metal-complexing template polymer has been prepared in the mixed solution of methanol and tetrahydrofuran by molecular imprinting technique. The coordination structure and complex ratio between quercetin and Ni+2 were studied by UV-visible spectroscopy, and the ternary complexation of quercetin, Ni+2 and methacrylic acid was verified by similar methods. Selective adsorption experiments for substrates indicated that compared with quercetin’s structural analogs (baicalein and baringenin), quercetin-Ni+2 template polymer prepared with appropriate amount of cross-linker exhibited significant adsorption selectivity for quercetin in the presence of Ni+2. The separation factors were 3.915 and 5.443 respectively, which also showed that adsorption capacity was greatly influenced by the amount of cross-linker.