Separation and Purification of Polyunsaturated Fatty acids by Chromatographic Process with Surface-treated Polymer Microspheres

采用悬浮聚合法制备了聚（苯乙烯-羟基甲基丙烯酸甘油酯）（聚（St-GMA））微球，为分离二十二碳六烯酸（DHA）和二十碳五烯乙酸（EPA）等多不饱和脂肪酸（PUFAs）提供了高分子微球。聚合物微球表面环氧基与一水亚氨基乙酸二钠发生开环反应，具有离子交换性能。在聚合物微球上引入离子交换基团后，将Na^+与Ag^+交换，制备表面含Ag^+的聚合物微球。已知多不饱和脂肪酸碳碳双键的π电子与Ag^+反应形成π配合物，说明聚合物微球表面的Ag^+对多不饱和脂肪酸具有亲和力。用Langmuir等温线很好地描述了Ag^+在表面处理的聚合物微球上的吸附平衡。采用不同Ag +含量的聚合物微球对DHA乙酯（DHA- et）进行了吸附实验。结果表明，聚合物微球上Ag^+的数量是吸附DHA-Et的重要决定因素。二十二碳六烯酸的吸附量随着Ag +吸附量的增加而增加。

Poly (styrene-co-glycidyl methacrylate) (poly (St-GMA)) microspheres were prepared by the suspension polymerization, providing the polymer microspheres for separation of polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaacetic acid (EPA). These polymer microspheres had a potential to have ion-exchange property by ring-opening reaction of epoxy groups on the surface with disodium iminoacetate monohydrate. After the introduction of ion-exchange group onto polymer microspheres, Na^+ was exchanged with Ag^+ to prepare polymer microspheres bearing Ag^+ on their surface. It was well-known that π-electrons of carbon-carbon double bonds of polyunsaturated fatty acids were reacted with Ag^+ to form π-complexes, indicating that Ag^+ on the polymer microsphere surface have the affinity for polyunsaturated fatty acids. Adsorption equilibrium of Ag^+ on surface-treated polymer microspheres was well described with Langmuir isotherm. Adsorption experiments of ethyl ester of DHA (DHA-Et) were carried out with polymer microspheres having various amount of Ag^+. As a result, the amount of Ag^+ on polymer microspheres was found to be a significant determinant for adsorption of DHA-Et. The amount of docosahexaenoic acid adsorbed increased with an increase in amount of Ag^+ adsorbed.