[The effect of organic modifier on the capacity factor of the solute in the micellar electrokinetic capillary...

In this paper the mass action law has been used to study the relationship of solute, organic modifier and micelle in the micellar electrokinetic capillary chromatography. A series of equations were given showing the relationship of capacity factor(k) of the solute, equivalent constant, concentration of solute and migration speed under the condition of using only one organic modifier. The results showed that the organic modifier can, to some extent, be dissolved in micelles. It has almost no effect on micellar actual migration speed, but, the organic modifier influences the CMC of surfactants and the distribution of solutes between two phases and results in the change of the capacity factors of the solutes. No simple equations like those in HPLC can be used to show the effect of organic modifier and surfactants on k. At the first approximation, they have the following equation, lnk approximately a + bCB + clnCB where, CB is the total concentration of organic modifier, a, b and c are constants.