Development of chiral ligand-exchange method using selector ligand and/or metal ion cocktails

Using a singular ligand and a dual central ion in a background electrolyte, a ligand exchange CE was investigated for the simultaneous enantioseparation of malic, tartaric and isocitric acids. Tartaric acid was enantioseparated by a ligand exchange CE with 100 mM D-quinic acid as a singular ligand and 10 mM Cu(II) ion as a singular central ion, but malic and isocitric acids were not enantioseparated. Addition of 1.8 mM Sc(III) ion to the background electrolyte with 10 mM Cu(II) ion to create a dual central metal ion system permitted the simultaneous determination of these alpha-hydroxy acid enantiomers and citric acid. The proposed ligand exchange CE was thus well suited for detecting adulteration of fruit juices.