中文摘要：

研究了某些生物碱在十八烷基膦酸改性锆-镁复合氧化物固定相（C18PZM）上的色谱行为.通过考察流动相参数如甲醇含量、缓冲液pH值和离子强度对生物碱保留的影响,对这类化合物在该固定相上的保留机理进行了探讨.结果表明,在实验色谱条件下,生物碱在C18PZM上表现出反相和阳离子交换的混合保留模式机理.锆-镁基质上化学吸附的十八烷基膦酸和其对流动相中路易斯碱的吸附以及锆羟基本身均有可能是该固定相的离子交换作用位点的来源.高pH值流动相,溶质大部分以分子状态使用形式存在,因此其保留以疏水作用为主.在甲醇-pH 10.1 Tris缓冲液,生物碱的分离取得了满意的结果.与传统的烷基键合硅胶反相固定相相比,C18PZM表现出了更优越的化学稳定性,对于碱性化合物,尤其是具有高pKa值的碱性化合物的分离分析有着广泛的应用前景,有望发展为与硅胶键合固定相互补的一类反相HPLC的固定相.

英文摘要：

The high performance liquid chromatography behavior of some alkaloids was studied on a magnesiazirconia （C18PZM） stationary phase modified by n-octadeeylphosphonic. The effect of mobile phase variables such as methanol content, ionic strength and pH on their chromatography behavior was investigated. The retention mechanism of alkaloids on the stationary phase was elucidated. The results indicate that beth hydrophobic and cation-exchange interactions contribute to the retention of alkaloids under most chromatographic conditions. The chemisorbed phosphonate and the adsorbed Lewis base anionic buffer constituents on accessible ZM surface Lewis acid sites also the inherent Brtnsted-acid sites play a role in the retention of ionized solutes by cation-exchange interaction. However, at high pH, the retention of alkaloids depends mainly on hydrophobic interactions between solutes and support. Satisfactory separations of alkaloids have been achieved with pH 10. 1 mobile phase. The C18 PZM seems to be an excellent altemative to silica-based reversed-phase stationary phase for the separation of strongly basic solutes.