Abstract
Micellar electrokinetic chromatography(MEKC) is one of the separation modes of capillary electrophoresis(CE) with high resolution. MEKC is useful for enantioseparations of organic compounds within a short analysis time even though sample volumes are very low. It has been considered that the hydrophobic interaction between solute and micelles is very important for enantioseparation of compounds. However, it has not been clearly understood what parameters are closely related to the separation mechanism of the MEKC. In the present study, The GA-PLS method was applied to find important parameters for the enantioseparations of amino acids using the MEKC with bile acids. For that purpose, the technique was used to enantioseparate eleven amino acids. Four bile acids such as cholic acid(CA), taurocholic acid(TCA), chenodeoxycholic acid(CDCA) and deoxycholic acid(DA) were adopted to make micellars interacting with the amino acids. The resolution values were calculated from the experimental results. The value is an index for the ability of the MEKC to enantioseparate the amino acids. Experimental values and physical properties such as hydropathy index of amino acids and isoelectric points of amino acids were used as explanatory variables for the statistical method. It was confirmed that three or four variables are enough to expect the experimental Rs values for CDCA and DCA while it is impossible to explain those for CA and TCA. It was considered that the difference of the hydrophilic property of the bile acids is the key to understanding the enantioseparations observed.
