分子印迹聚合物选择性富集长春碱的研究
摘要
Molecularly imprinted polymers (MIPs) are synthetic tailor-made polymers with high selectivity towards a particular substance (template). A MIP using vinblastine (VLB) as the template molecule was synthesized and characterized. The presence of monomer-template complexes in a non-covalent way was confirmed by UV-vis spectrometry analysis. The polymerization was performed using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linking agent, and toluene as porogenic solvent by a thermo-polymerization method. The characterization of the obtained MIP was evaluated by scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) analysis. It was observed that the morphology of the MIP was more porous and rough, and the surface area had a significant increase than that of non-imprinted polymer (NIP). This MIP was used as the sorbents of (SPE) to assess the selectivity of the MIP after optimization of the SPE protocol. VLB was specifically adsorbed on the MIP cartridge, while to vincristine (VCR), the chemical analogue of VLB, almost no selective binding appeared. On the basis of the results, <italic>Catharanthus roseus</italic> extract were applied to the MIP cartridge for investigating its capability to extract VLB from the plant extract, and the capacity of the MIP cartridge was also evaluated. It was shown that the MIP could effectively enrich VLB from C. roseus extract and the recovery amounted to 93.8%. Surprisingly, the solvents dissolving the samples had significant influence on the capacity of the MIP cartridge; it was 750 μg/g[0] in toluene, 625 μg/g[0] in chloroform, and 250 μg/g[0] in methanol, respectively.