Bumgarner J G, Khaledi M G
Department of Chemistry, North Carolina State University, Raleigh 27695-8204, USA.
J Chromatogr A. 1996 Jul 12;738(2):275-83. doi: 10.1016/0021-9673(96)00081-7.
The separation of a complex mixture of 17 corticosteroids was investigated by mixed micellar electrokinetic chromatography (MMEKC) employing various bile salts and/or alkylsulfonates. In this study, influence of individual surfactants and mixed micelles of hydrocarbon-bile salt surfactants on retention behavior, selectivity and the size of the elution window is investigated. Retention behavior of corticosteroids in SDS and bile salt micelles is examined using linear solvation energy relationships (LSER). In addition, the effects of type of bile salt surfactant on elution patterns were investigated. It was found that separation patterns are mostly influenced by the number of hydroxyl functional groups on the steroidal backbone of the bile salts, while the type of ionic head group has little, if any, effect on the steroids separation. Comparisons between mixed micellar techniques and the inclusion of conventional modifiers to various single and binary surfactant systems were made. The addition of modifiers such as acetonitrile, urea and beta-cyclodextrin to SDS surfactant systems, as well as mixed bile salt systems of sodium taurocholate and sodium glycodeoxycholate, did not improve the separation of the steroids. On the other hand, the addition of the short-chain alkylsulfonate sodium butanesulfonate to the mixture of taurocholate and glycodeoxycholate greatly improved the separation of the 17 corticosteroids and provided a baseline separation of all solutes. The effects of carbon chain length and concentration of alkylsulfonate on capacity factor, selectivity, efficiency and the size of the elution window were investigated.
采用各种胆盐和/或烷基磺酸盐，通过混合胶束电动色谱法（MMEKC）研究了17种皮质类固醇的复杂混合物的分离。在本研究中，研究了单个表面活性剂以及烃-胆盐表面活性剂的混合胶束对保留行为、选择性和洗脱窗口大小的影响。使用线性溶剂化能关系（LSER）研究了皮质类固醇在SDS和胆盐胶束中的保留行为。此外，还研究了胆盐表面活性剂类型对洗脱模式的影响。结果发现，分离模式主要受胆盐甾体主链上羟基官能团数量的影响，而离子头基的类型对类固醇分离的影响很小（如果有影响的话）。对混合胶束技术与在各种单一和二元表面活性剂体系中加入传统改性剂进行了比较。向SDS表面活性剂体系以及牛磺胆酸钠和甘氨脱氧胆酸钠的混合胆盐体系中添加乙腈、尿素和β-环糊精等改性剂，并未改善类固醇的分离效果。另一方面，向牛磺胆酸盐和甘氨脱氧胆酸盐的混合物中添加短链烷基磺酸钠丁磺酸钠，极大地改善了17种皮质类固醇的分离效果，并实现了所有溶质的基线分离。研究了烷基磺酸盐的碳链长度和浓度对容量因子、选择性、效率和洗脱窗口大小的影响。
