Effect of metal ions on enantioseparation of five amino acids by ligand exchange capillary zone electrophoresisEI北大核心CSCD

Enantioseparation of five amino acids was conducted by chiral ligand exchange capillary zone electrophoresis (CLE-CZE). L-His and different metal ions in a certain proportion were used to form chiral recognition complexes. The enantiomers were exchanged with L-His ligands in the complex. Then, the separation of enantiomers was obtained according to the different ligand exchange ability. Effects of the valence and the electron layers of metal ions on the resolution were investigated systemically. Baseline separation of D, L-Phe, D, L-Tyr and D, L-Trp was obtained within 12 min when 4 mmol/L Co(Ⅱ) and 8 mmol/L L-His were added to the phosphate buffer solution (20 mmol/L, pH 8.0). The resolutions of D, L-Phe, D, L-Tyr and D, L-Trp were 1.53, 2.04, and 1.58, respectively. Partial chiral separation of D, L-Ser and D, L-Val was achieved under the same conditions. When Co(II) was used as the central ion, the resolution was better than that of Cu(II) and Zn(II), although they had the same number of electron layers and valence. The resolution of amino acids with Ag(I) as the central ion was not as good as that of divalent metal ions. Metal ions with three electron layers had better separation results than that with four electron layers. © 2023, Youke Publishing Co.,Ltd. All rights reserved.