Evaluation of the Use of Various Surfactants in Micellar Electrokinetic Capillary Chromatography

Abstract

Two common anionic surfactants, sodium decyl sulfate (STS) and sodium dodecyi sulfate (SDS), and two common cationic surfactants, dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium chloride (CTAC), are investigated as “pseudo-stationary phases” in micellar electrokinetic capillary chromatography. A group of twelve test solutes chosen to highlight specific solute-micelle interactions are used to explore the retention properties of these surfactant systems at various applied voltages. These studies indicate that the SDS system can be used analogously to the ODS stationary phase in HPLC. It is very consistent in its retention characteristics and suitable for a fairly wide range of solutes. The CTAC system is useful for moderately large molecular weight solutes where solubilization in the aqueous mobile phase is limited.