Sodium maleopimaric acid as pseudostationary phase for chiral separations of amino acid derivatives by capillary micellar electrokinetic chromatography

A new type of chiral surfactant, sodium maleopimaric acid (SMA), was synthesized, and employed for the enantioselective micellar electrokinetic chromatographic (MEKC) separation of amino acid enantiomers derivatized with naphthalene-2,3-dicarboxaldehyde (NDA-D/L-AAs). The effect of the surfactant concentration, type and concentration of the BGE, and buffer pH on the resolution was studied, and optimized conditions were used to evaluate the ability of this new surfactant to perform chiral separations toward NDA-D/L-AAs by MEKC. Enantiomeric separations of NDA-D/L-AAs were achieved with a running buffer consisting of 100 mM borate (pH 9.5) and 20 mM SMA in a 58.5 cm length x 50 gin id capillary. Under the conditions selected, two pairs of tested amino acid enantiomers including NDA-D/L-trptophan (Trp) and NDA-D/L-kynurenine (Kyn) were resolved.