Improvement of Separation in Non-Aqueous Capillary Electrophoresis using Surfactants and Calixarenes as Additives

In this study the effect of the presence of some different additives on non-aqueous capillary electrophoresis (NACE) separations of some structurally related compounds belonging to beta-blockers, antidepressants or neuroleptics were examined. Presence of surfactant was found to have a strong effect on separations. The anionic surfactant sodium dodecyl sulfate (SDS) enhanced separation of neuroleptics and beta-blockers. Upon combination between SDS and toctyl-calixarene-tetra-ethylester (TOCXTEE) separation of beta-blockers could be optimized. Use of cyanomethylcalixarene (CMCX) with buffer including SDS for separation of neuroleptics elongated the separation time and had some positive and negative effects on separation. The cationic surfactant tetrabutylammonium-bromide (TBAB) was found to be better than that of SDS for the separation of antidepressants. Structure of analytes and calixarenes played an effective role in separation.