动态磁涂覆混合固定相开管毛细管电色谱中电渗流的特征

Characteristics of electroosmotic flow in open-tubular capillary electrochromatography with magnetic nanoparticle coating as mixed-mode stationary phase

将表面分别被改性成C18和氨基的磁性纳米颗粒按照不同比例混合,制备成具有不同分离选择性的混合固定相,进一步采用动态磁涂覆的方法制备开管毛细管电色谱柱。通过考察这种色谱柱中不同种类固定相表面物理化学性质对电渗流的综合影响,从理论上说明了其电渗流的特征。分别在不同固定相配比及不同涂覆长度条件下进行实验,理论与实验结果相符,证实通过调节固定相配比或磁铁对数可以便捷地调节电渗流的大小。

A novel open-tubular capillary electrochromatography（OT-CEC） column with magnetic nanoparticle coating as mixed-mode stationary phase was prepared.The mixed-mode stationary phases were obtained by mixing C18 and amino modified magnetic nanoparticles with different ratios.The mixed modified magnetic nanoparticles as stationary phase were introduced into the capillary by using external magnetic force.The magnetic nanoparticle coating can be easily regenerated by removing the external magnetic field,and applied to other separation modes.The characteristics of electroosmotic flow（EOF） were theoretically investigated through the effect of physicochemical properties of different stationary phases on EOF.The experiment was conducted under different ratios of mixed-mode stationary phases and coating lengths,and it was verified that the theoretical conclusions accorded with the experimental results.It was shown that the EOF can be easily adjusted by changing the ratio of stationary phases or the number of permanent magnets.