对-叔丁基杯[8]芳烃键合硅胶制备及其毛细管电色谱性能研究

以γ-(环氧丙氧)丙基键合硅胶为前体,于硅胶表面键合环氧基,在催化剂存在下以杯芳烃钠盐开环制备杯芳烃键合硅胶固定相.该方法反应条件温和,适用性强.将这个新方法首次用于制备对-叔丁基杯[8]芳烃电色谱键合固定相(C8BS),采用加压电色谱初步评价其电色谱性能.研究结果表明,C8BS电渗流(Electrosmoticflow,EOF)较小,但通过控制键合反应及使用压力辅助电色谱可部分弥补上述不足.该固定相的EOF受流动相pH影响小(pH=3-8),同时大环配体屏蔽效应能有效地克服硅羟基引起的碱性化合物拖尾现象,这对电色谱分离具有重要意义.通过分步封尾研究EOF的来源发现,杯芳烃酚羟基对EOF有弱的贡献,这与报道的杯芳烃涂层具有径向电渗流调控能力相一致.

Preparation and Performance of p-tert-Butyl-calix[8] arene-bonded Silica Gel for Capillary Electrochromatography

A new method for the preparation of calix-arene-bonded stationary phases(C8BS) was developed via the breaking epoxy group on the solid surface of the bonded 3-glycidoxypropyl silica by using active phenolic sodium of calix-arene in the presence of phase-transfer catalyst, which is moderate and universal. The new method was first introduced to the preparation of calixarene-bond stationary phase for capillary electrochromatography(CEC) with some modification. The new stationary phases were evaluated by the pressurized CEC(pCEC). The results show that the calixarene-bonding can provide lower and stable EOF over a wide pH range from 3-_8, and the peak shapes of basic compounds on silica gel matrix can be improved because of the shield effect of the macrocyclic ligand, which are very important to CEC. Additionally, EOF source was studied by using silanization step by step. The result shows that the phenolic hydroxyl groups on the calixarene-bonded stationary phase result in EOF partially, which is consistent with the open-column of CEC reported.