Zn2+配位双模板印迹聚合物的制备表征及同时萃取升麻中的阿魏酸和咖啡酸

以Zn²⁺-阿魏酸-咖啡酸配合物为模板制备了双分子印迹聚合物,优化了制备条件,用傅里叶红外光谱和扫描电镜对分子印迹聚合物进行结构表征,测试了分子印迹聚合物的吸附特性,探讨了分子印迹聚合物固相萃取应用效能并对萃取条件进行了优化.结果表明,当预反应混合液中金属离子、模板总量(阿魏酸-咖啡酸摩尔比为2:3)、功能单体及交联剂用量比为1:1:3:30(摩尔比)时,所得印迹聚合物对两种模板(阿魏酸和咖啡酸)均具有最好的吸附性能,吸附量分别达51.12mg/g和70.26mg/g.吸附动力学测试表明吸附3h,分子印迹聚合物可达到吸附平衡.用分子印迹聚合物进行固相萃取时,优化的淋洗过程为1.00mL H₂O、1.00mL甲醇-H₂O (3/7,体积比)及1.00mL甲醇-H₂O-ACN (4/4/2,体积比),洗脱溶剂为2.00mL甲醇.在优化条件下,分子印迹聚合物可同时选择富集升麻初提液中的阿魏酸和咖啡酸,二者回收率分别为92.67%和95.42%,而且产品中杂质少于用硅胶萃取所得产品.

Preparation and characterization of Zn2+-bi-templates imprinted polymers for the simultaneous extraction of ferulic acid and caffeic acid in Rhizoma Cimicifugae

A group of bi-templates imprinted polymers (MIPs) was synthesized using Zn²⁺-ferulic acid-caffeic acid complex as the template. The preparation conditions were optimized. Structural characterizations were performed using FTIR and SEM and the adsorption capacity was tested. Also, the applicability of this MIP in the solid phase extraction was explored after the washing and elution conditions were optimized. Results indicated that when the molar ratio of Zn²⁺-two templates (the molar ratio of ferulic acid to caffeic acid was 2:3)-functional monomer-cross linker was 1:1:3:30 in the pre-polymerization mixture, the obtained imprinted polymer possessed the highest adsorption capacity toward two templates, with a value of 51.12mg/g for ferulic acid and 70.26mg/g for caffeic acid. The adsorption equilibrium can be reached within 3h. The optimized conditions for this MIPs phase extraction were 1.00mL H₂O, 1.00mL methanol-H₂O mixture (3/7, volume ratio) and 1.00 mL methanol-H₂O-acetonitrile mixture(4/4/2, volume ratio) for the washing procedure and 2.00 mL methanol for the elution one. This MIP revealed selective enrichment capability toward ferulic acid and caffeic acid in the crude extract of Rhizoma Cimicifugae, with recovery rates of 92.67% and 95.42% respectively under the optimized conditions. The product contains less impurities than that obtained by silica solid phase extraction.