Ye Fanggui, Li Shuting, Zhao Shulin
College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin, China.
J Sep Sci. 2007 Nov;30(17):3027-34. doi: 10.1002/jssc.200700316.
Monolithic columns have been prepared with a novel bonded silica stationary phase, tetradecylamine bonded silica (TDAS), and used in pressurized capillary electrochromatography (pCEC). The monolithic silica column matrix was prepared by a sol-gel process and then chemically modified with the spacer (3-glycidoxypropyl)trimethoxysilane and tetradecylamine. The introduced embedded polar amine groups dominated the charge on the surface of the monolithic stationary phase and generated an EOF from cathode to anode under acidic conditions. The tetradecyl hydrophobic chains in TDAS provide chromatographic interactions. The chromatographic characteristics of the prepared monolithic column were studied. Some aromatic compounds including alkylbenzenes, aromatic hydrocarbons, phenols, and anilines were successfully separated on the TDAS monolithic column in pCEC mode. As expected, the TDAS monolithic stationary phases exhibit typical reversed-phase electrochromatographic behavior toward neutral solutes due to the introduced tetradecyl groups. Hydrophobic as well as electrophoretic migration processes within the monoliths were observed in the separation of basic anilines. Symmetrical peaks can be obtained for anilines because the embedded polar amine groups on the surface can effectively shield the adsorption of positively charged analytes onto the stationary phase.
已使用新型键合硅胶固定相十四烷基胺键合硅胶(TDAS)制备了整体柱,并将其用于加压毛细管电色谱(pCEC)。整体硅胶柱基质通过溶胶 - 凝胶法制备,然后用间隔物(3 - 环氧丙氧基丙基)三甲氧基硅烷和十四烷基胺进行化学修饰。引入的嵌入极性胺基团主导了整体固定相表面的电荷,并在酸性条件下产生了从阴极到阳极的电渗流(EOF)。TDAS中的十四烷基疏水链提供色谱相互作用。研究了所制备整体柱的色谱特性。在pCEC模式下,一些芳香族化合物,包括烷基苯、芳烃、酚类和苯胺类,在TDAS整体柱上成功实现了分离。正如预期的那样,由于引入了十四烷基基团,TDAS整体固定相对中性溶质表现出典型的反相电色谱行为。在碱性苯胺的分离过程中,观察到了整体柱内的疏水以及电泳迁移过程。对于苯胺类可以获得对称峰,因为表面嵌入的极性胺基团可以有效地屏蔽带正电分析物在固定相上的吸附。