Abstract: A novel surface molecularly imprinted polymers was synthesized using poly (vinyl alcohol) modifed multi-walled carbon nanotubes (MWNTs) as supporting matrix, ursolic acid (UA) as the template molecule, methacrylic acid (MAA) as the functional monomer, and ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent. Effect of different molar ratios of the functional monomer to the template on the performance of the synthesized MWNTs-MIPs was discussed and the results showed that the optimum ratio was 4:1. The multi-walled carbon nanotubes-molecularly imprinted polymers (MWNTs-MIPs) were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The results showed that a stable imprinted layer was grafted on the MWNTs surface successfully. The adsorption properties were demonstrated by static adsorption and adsorption kinetic experiments. The results demonstrated that the MWNTs-MIPs had specific selectivity for UA, yielding a maximum adsorption capacity of 53.1 μmol/g and the equilibrium time takes about 60 min. Solid phase extraction condition was optimized,and the optimal condition was washing with 100% methanol and eluting with 10% acetic acid methanol solution. Packed into the solid-phase extraction (SPE) column, the MWNTs-MIPs-SPE column could be applied to separate ursolic acid (UA) from similar structure oleanolic acid (OA).
Template and target information: ursolic acid, UA
Author keywords: carbon nanotubes, Solid-phase extraction, surface molecular imprinting, Ursolic acid

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