Liu Min, Li Lai-Sheng, Da Shi-Lu, Feng Yu-Qi
Department of Chemistry, Wuhan University, Wuhan, PR China.
Talanta. 2005 Apr 15;66(2):479-86. doi: 10.1016/j.talanta.2004.09.022.
Beta-cyclodextrin, p-tert-butyl-calix[8]arene and chloropropyl bonded silica stationary phases have been prepared and were applied at the same time to develop a chromatographic procedure to separate steroids. In order to select the best type of stationary phase for the analysis, similar preparation processes of the two kinds of macrocycle stationary phases with the same spacer were adopted respectively. The chromatographic behaviors and retention mechanisms of the two kinds of macrocycle stationary phases for steroids were systematically studied and compared with those of chloropropyl bonded silica and ODS. The effect of mobile phase variables, such as methanol content, pH value of buffer, ionic strength and buffer composition on chromatographic behaviors was investigated. The results showed that the retention mechanisms of the four stationary phases for steroids were obviously different, and excellent separation was achieved on beta-cyclodextrin bonded silica stationary phase (beta-CD-BS), as a consequence of the structure and the properties of the stationary phase. The retention process on beta-CD-BS exhibited inclusion complexation, hydrogen-bonding and weak hydrophobic interaction, while for p-tert-butyl-calix[8]arene bonded silica stationary phase (CBS), pi-pi and hydrogen-bonding besides hydrophobic interaction played an important role.
已制备了β-环糊精、对叔丁基杯[8]芳烃和氯丙基键合硅胶固定相，并同时应用于开发一种分离甾体的色谱方法。为了选择用于分析的最佳固定相类型，分别采用了具有相同间隔基的两种大环固定相的类似制备过程。系统研究了两种大环固定相对甾体的色谱行为和保留机理，并与氯丙基键合硅胶和十八烷基硅烷键合硅胶（ODS）的色谱行为和保留机理进行了比较。研究了流动相变量，如甲醇含量、缓冲液pH值、离子强度和缓冲液组成对色谱行为的影响。结果表明，四种固定相对甾体的保留机理明显不同，由于固定相的结构和性质，在β-环糊精键合硅胶固定相（β-CD-BS）上实现了优异的分离。在β-CD-BS上的保留过程表现为包合络合、氢键作用和弱疏水相互作用，而对于对叔丁基杯[8]芳烃键合硅胶固定相（CBS），除疏水相互作用外，π-π相互作用和氢键作用也起重要作用。
