Electromigration of ionic micelles by the use of an isotachophoretic apparatus

Electromigration experiments of ionic surfactants were performed by using a capillary tube isotachophoretic apparatus. The zone of the migrated surfactant was collected after separation, and the surfactant concentration of the migrated zone was determined by HPLC analysis. The surfactant concentration of the migrated zone was increased with an increase in electrolyte concentration, and was in accord with the prediction of the Kohlrausch equation. When the electrolyte concentration further increased, the surfactant molecules began to migrate as a micellar state. Moreover, the mixed systems of ionic-non ionic and ionic-ionic surfactants were also examined and revealed the migration as mixed micelle.