羧甲基壳聚糖修饰的开管毛细管电色谱柱的制备与表征

以γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷为偶联剂,将羧甲基壳聚糖键合至毛细管内壁上。对毛细管预处理、硅烷化以及羧甲基壳聚糖键合反应参数进行了优化,考察了开管柱内表面结构形貌、电渗流、重现性和电色谱分离性能。扫描电镜图显示羧甲基壳聚糖均匀地键合在毛细管内表面。调节流动相的pH值可产生正向和反向电渗流,电渗流的相对标准偏差(RSD): 日内小于0.8%(n=6)、日间小于3.5%(n=3)、同一批次间小于4.3%(n=3)、不同批次柱间小于6.1%(n=3),重现性较好。4种核苷酸(腺嘌呤核苷酸、鸟嘌呤核苷酸、胞嘧啶核苷酸、尿嘧啶核苷酸)在修饰后的毛细管电色谱柱上得到了较好的分离,柱效达到36000～182000 塔板/m。结果表明,所建立的开管柱制备方法简单有效、稳定性好。

Preparation and evaluation of open tubular capillary electrochromatographic column modified with carboxymethyl chitosan

Via covalent coupling of epoxy group, an open tubular column covalently modified with carboxymethyl chitosan (CMC) as stationary phase was prepared. The parameters of column pretreatment, silanization and chemically bonding of CMC were optimized. The morphology of inner wall of the open tubular column was observed by scanning electron microscope (SEM), which showed that the inner wall of the prepared column was evenly coated with a polymer film. Either positive or negative electroosmotic flow (EOF) could be achieved by varying the pH values of running buffer. Good reproducibility was obtained with the relative standard deviations (RSDs) of EOF less than 0.8% for run-to-run (n = 6), less than 3.5% for day-to-day (n = 3), less than 4.3% for column-to-column (n = 3) and less than 6.1% for batch-to-batch (n = 3). Nucleotides (AMP, GMP, CMP and UMP) were analyzed on the open tubular column modified with CMC, with high column efficiencies ranging from 36 000 to 182 000 plates/m. The results indicate that the developed method is effective, easy and stable.