Enantioseparation of o-phthaldiadehyde derivatized amino acids using beta-CD-modified micellar electrokinetic chromatography in the mixed aqueousorganic media

A method for the enantioseparation of amino acids derivatized with o-phthaldiadehyde (OPA) and N-acylated cysteine (AC) using beta-cyclodextrin (beta-CD)-modified micellar electrokinetic chromatography (MEKC) in the presence of organic modifier was developed. The effects of separation parameters, such as the pH value of the buffer, the concentration of the buffer, beta-CD, bile salt and organic modifiers, on the migration times and resolutions of chiral amino acids were investigated and the optimum experimental conditions were 40mmoll1 borax (pH 9.0), 60mmoll-1 sodium taurocholate (STC), 30mmoll-1 beta-CD and 15% (v/v) of isopropanol (IPA). Using the proposed method, 11 pairs of OPA/AC-DL-amino acids were separated simultaneously with the resolution ranging from 1.038 to 3.367 in less than 19min.