Micellar electrokinetic capillary chromatography of three natural vitamin A derivatives.

Micellar electrokinetic chromatography (MEKC) using bile salts has been employed to separate retinoids differing in structure and charge; bile salts in MEKC allows the separation of liposoluble molecules but, to the best of our knowledge, there are only few data on the above-mentioned technique for the separation of highly hydrophobic compounds. The three natural vitamin A derivatives, retinal, retinol and retinoic acid, were successfully separated by MEKC using sodium cholate within a relatively short time (ca. 25 min), whereas the separation of these compounds was not successful using sodium dodecyl sulfate or sodium deoxycholate. Several parameters (pH and organic modifiers, in addition to bile salts concentration) have been tested to provide a system that can be extended to synthetic retinoids, which are often used in treating several diseases, including cancer prevention and therapy.