Separation of enantiomers by micellae electrokinetic chromatography with chiral surfactant

Several synthetic chiral surfactants such as N-dodecanoyl- or N-tetradecano yl-L-amino acids were used as the chiral selector respectively. The neutral , acidic and basic enantiomers such as a-chloropropionanilide, 2-amino-3-(4 -nitrophenyl)-1, 2-propanediol and warfarin were separated by MEKC. The eff ects of the type and concentration of chiral surfactants, pH of buffer solu tion on the enantiomeric separation were investigated. The results showed t hat the side group of amino acid and the chain length of hydrophobic alkyl group in chiral surfactant molecule had a significant influence on the sepa ration. The concentration of chiral surfactant was an important factor infl uencing the enantiomeric separation. Both retention time and resolution inc reased with increasing the concentration of chiral surfactant. The optimum concentration was in the range from 100 to 150 mmol/L for the test samples. The pH of buffer solution had a dramatic effect on separation Of the weak basic or acidic enantiomers, but little effect on neutral enantiomer. Under the selected condition, several test enantiomers were successfully separat ed. The separation efficiency was more than 1x10(5) theoretical plates per meter.