Investigations of Micelle Formation Using Capillary Electrophoresis

Abstract

The formation of sodium dodecyl sulfate (SDS) and chlorpromazine hydrochloride (CPZ) micelles was studied using capillary electrophoresis (CE). The elution time of a neutral marker was used to determine when the surfactant had changed from its monomer to micelle form. The marker's interactions with the surfactant changed as the monomer formed micelles, and caused the marker's elution time to change as well. The elution times of a range of surfactant concentrations were graphed, and from this data the critical micelle concentration (CMC) was determined. This method worked well for SDS using 2-naphthalenemethanol as the marker; the CMC was calculated to be 3.4 mM. This method, however, did not work as well for CPZ because of CPZ?s absorbance of ultraviolet and visible light. This characteristic caused a poor baseline for the electropherogram, and made finding a suitable marker difficult.