胶束溶液体系对毛细管电动色谱酸性化合物分离的影响

以阴离子表面活性剂十二烷基硫酸钠（SDS）、非离子表面活性剂吐温20（ Tween 20）及两者组成的混合胶束体系作为毛细管胶束电动色谱（MECC）的分离介 质，进行4种结构相似的酸性化合物的MECC分离研究，考察了胶束的类型、表面活 性剂的浓度、缓冲溶液的pH值及有机改性剂乙醇对分离的影响。结果表明各因素对 酸性药物的MECC分离有不同的影响规律。SDS胶束体系对溶质的保留值最大， Tween 20体系的保留值最小，二者的分离选择性正好相反，混合胶束体系的分离行 为则介于两者之间；在SDS和Tween 20体系中，表面活性剂浓度增加，溶质的保留 时间均随之递增，混合胶束体系中，总浓度一定，随Tween 20配比的增加，溶质的 保留时间先减少后增加；缓冲溶液的pH值增大，使溶质的分离效果均能变差；有机 改性剂乙醇的加入对容量因子的影响主要与溶质的疏水性有关，并对分离作用机理 进行了探讨。在SDS和Tween 20 MECC体系下，分别进行了实样测定，取得了满意的 结果。

Effect of Micellar Solution Systems on Acidic Compound Separation by Electrokinetic Chromatography

Pseudo-stationary phases with sodium dodecyl sulfate (SDS) as an anionic surfactant, Tween 20 as a nonionic surfactant or SDS-Tween 20 mixed micelles were examined to control the separation and migration behavior of four acidic compounds similar in structure, including ketoprofen, naproxen, sulindac and indometacin in micellar electrokinetic capillary chromatography (MECC). Various parameters such as type of micelles, surfactant concentration, buffer pH and ethanol as organic modifier that affect the separation were studied. Complete separations of these acidic drugs were respectively achieved in SDS, Tween 20 or mixed micelle system. The retention time of solutes was the longest in SDS system and the shortest in Tween 20 system, and the elution order was reversed each other. The retention time of analytes increased with increasing surfactant concentration in the SDS or Tween 20 system. In the mixed micelle system, the total surfactant concentration was kept constant and large differences in selectivity were achieved by changing the micellar mole fractions. The resolution of analytes became worse as the buffer pH increased from 6.2 to 7.6. The addition of ethanol exerted a strong effect not only on flowing phase but also on micellar phase, so the capacity factors of the analytes changed differently with the increase of the ethanol concentration. The hydrophobicity of analytes played a significant role in the influence on the separation behaviors in the MECC systems. At last, in the two systems of SDS-MECC and Tween 20-MECC, the contents of sulindac and indometacin in tablets were determined and satisfactory results were obtained.