A cost-effective and eco-friendly approach for extraction and clean-up of sinapic acid was developed via the use of molecularly imprinted polymers (MIPs). Acetonitrile/methanol (5:1) was used as the porogenic solvent system, sinapic acid as the template, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent were used to prepare MIPs via precipitation polymerization. A series of MIPs were synthesized with variable template: monomer: cross-linker mole ratios: 1:4:20, 1:8:20 and 1:8:32. Polymers were characterized by complementary methods: scanning electron microscopy (SEM), dynamic light scattering (DLS), gas adsorption analysis, infrared absorption spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The batch rebinding experiments were conducted to evaluate polymer performance in terms of relative binding affinity towards the template. The initial concentration and solution pH strongly affect the binding capacity of polymers in aqueous media. Moreover, the fabricated MIPs were successfully applied for extraction of sinapic acid from rapeseed meal extract.

A schematic of molecularly imprinted polymer for extraction of sinapic acid from aqueous solutions

通过使用分子印迹聚合物（MIP），开发了一种经济高效且环保的提取和净化芥子酸的方法。以乙腈/甲醇（5：1）为成孔剂体系，以芥子酸为模板，以甲基丙烯酸为功能单体，以乙二醇二甲基丙烯酸酯为交联剂，通过沉淀聚合制备MIP。合成了一系列具有可变模板的MIP：单体：交联剂摩尔比：1：4：20、1：8：20和1：8：32。聚合物通过互补方法进行表征：扫描电子显微镜（SEM），动态光散射（DLS），气体吸附分析，红外吸收光谱（FT-IR）和热重分析（TGA）。进行分批重新结合实验以根据对模板的相对结合亲和力评估聚合物性能。初始浓度和溶液pH值强烈影响聚合物在水性介质中的结合能力。而且，所制备的MIP成功地用于从菜籽粕提取物中提取芥子酸。

从水溶液中提取芥子酸的分子印迹聚合物示意图