有机-无机杂化硅胶基质整体柱的制备及其电色谱性能

Preparation and Evaluation of Organic-Inorganic Hybrid Silica Based Monolithic Columns for Capillary Electrochromatography

采用溶胶-凝胶法,以四乙氧基硅烷和苯基三乙氧基硅烷作为反应单体,通过酸碱两步催化在毛细管中进行原位缩聚反应,制备了新型有机-无机杂化硅胶基质毛细管整体柱,制备过程简单。整体柱基质中均匀分布的苯基基团可直接用于反相毛细管电色谱的分离,因而不需要对基质再进行衍生化。优化了整体柱的制备条件,采用扫描电镜和压汞法对整体柱的微观结构和孔径分布进行了表征。分别考察了溶胶-凝胶初始反应液中水的用量对柱床结构的影响和两种单体的配比对材料孔径分布的影响。研究了稠环芳烃类化合物在整体柱上的保留行为,用所制备的整体柱分离了7种苯酚类化合物,平均柱效达100 000塔板/m。

A new type of organic-inorganic hybrid porous silica-based monolithic columns was developed for reversed-phase capillary electrochromatography （RP-CEC）. The monolithic columns were prepared from in situ co-condensation of tetraethoxysilane （TEOS） and phenyltriethoxysilane （PTES） precursors via a two-step catalytic sol-gel procedure in the capillary to create phenyl groups distributed throughout the silica matrix for chromatographic interaction. The functionalized monolithic stationary phase was created without additional surface derivatization. The reaction conditions for the preparation of the monolithic columns were optimized. The structure and pore size distribution of the monolithic columns were characterized by scanning electron microscopy and mercury porosimetry, respectively. The effect of water concentration on the column structure was studied, and the influence of the ratio of two precursors on the pore size distribution was also investigated. The retention behavior of polycyclic aromatic hydrocarbons on the monolithic column is discussed. Seven phenols were also separated with an average efficiency over 100 000 plates/m.