[Separation model of small molecules with SEC columns and micellar mobile phase]

Small alkanol molecules were successfully separated with SEC method in combination with a micellar mobile phase. The separation model has been given in this system. The separation is based on the differential migration of the micelle and the surrounding water and the differential distribution of the solute between the micelle and aqueous phase, therefore, the separation mechanism is very similar to that of micella electrokinetic chromatography (MEKC). The retention volume of solute is related to the micellar concentration by theoretical treatment, through which the solute distribution coefficient between micelle and aqueous phase could be obtained. Two different SEC columns were employed for separation of some alkanols and the theoretical model is supported by the experimental results. The distribution coefficients obtained were in good agreement for these two columns.