Application of Novel Separation Field, Polymer Aggregate, to Capillary Electrophoresis

一些由聚[(N-酰亚氨基)乙烯]结构组成的两亲性嵌段共聚物，具有亲水嵌段和疏水嵌段，在水介质中形成直径100 nm的聚集体。将聚合物聚集体(AG)加入毛细管电泳色谱(CE)运行液中，再加入少量阴离子表面活性剂如十二烷基硫酸钠(SDS)，使聚集体表面带负电荷，使AG成为拟固定相(AG-CE)。因此，中性化合物，如酚，按亲脂性的顺序迁移。与传统的十二烷基硫酸钠胶束电动层析(SDS-MEKC)相比，硝基苯酚的迁移被大大延缓。这些阴离子物种既不加入AG，也不加入十二烷基硫酸钠胶束。AG胶束的电荷密度远小于十二烷基硫酸钠胶束。因此，与SDS-MEK不同，在AG-CE中，阴离子物种的迁移小于阴离子物种的迁移。为了得到一种新型的胶束层析，在反相色谱(AG-LC)中，将AG加入到流动相中。AG-LC对萘磺酸盐类化合物的分离显示出与传统胶束层析明显不同的选择性，通过两亲性嵌段共聚物的分子修饰来表达进一步的分子识别能力，有望为AG在毛细管电泳色谱及相关层析技术中的应用开辟新的途径。

Some amphiphilic block-copolymers consisting of poly [(N-acylimino) ethylene] structure, which has hydrophilic blocks and hydrophobic blocks, form aggregates of 100 nm diameter in aqueous media. The polymer aggregate (AG) was added to the running solution of capillary electrophoresis (CE), and the further addition of a small amount of anionic surfactant, such as SDS, to provide negative charges onto the aggregate surface resulted in the functioning of AG as a pseudo-stationary phase (AG-CE). Thus, neutral compounds, such as phenols, were migrated in the order of lipophilicity. Compared to the conventional micellar electrokinetic chromatography by use of SDS (SDS-MEKC), the migration of nitrophenols was greatly retarded. Such anionic species are incorporated neither into AG nor into SDS micelles. The charge density of AG is much smaller than that of SDS micelles. Therefore, it appears that the migration of neutral species, which are incorporated in SDS micelles are smaller than that of the anionic species, whereas such a delay in the neutral species migration was not observed for the species incorporated in AG.Consequently, in AG-CE the migration of anionic species is smaller than that of neutral species incorporated in AG, unlike SDS-MEKC.To attain a novel micellar chromatography, the AG was added to the mobile phase in a reversed-phase chromatography (AG-LC). For the separation of naphthalenesulfonate derivatives, AG-LC showed a considerably different selectivity from that for the conventional micellar chromatography.In the future, the expression of further molecular recognition ability through the molecular modification of amphiphilic block-copolymers will hopefully lead to new applications of AG to CE and related chromatography technologies.