Liping Zhao, Juan Qiao, Ke Zhang, Dan Li, Hongyi Zhang,* and Li Qi*
Abstract: A chiral ligand exchange capillary electrochromatography (CLE-CEC) protocol was designed andimplemented for d,l-amino acids enantioseparation with poly(maleic anhydride-styrene-methacryloyl-l-arginine methyl ester) as the coating. The block copolymer was synthesized through the reversibleaddition fragmentation chain transfer reaction. In the constructed CLE-CEC system, poly (methacryloyl-l-arginine methyl ester) moiety of the block copolymer played the role as the immobilized chiral ligandand Zn (II) was used as the central ion. Key factors, including pH of buffer solution, ratio of Zn (II) toligands, the mass ratio of monomers in the block copolymer, which affect the enantioresolution wereinvestigated. Comparing with the bare capillary, the CLE-CEC enantioresolution was enhanced greatlywith the coating one. 5 Pairs of d,l-amino acids enantiomers obtained baseline separation with 5 pairspartly separated. The mechanism of enhancement enantioresolution of the developed CLE-CEC systemwas explored briefly. Further, good linearities were achieved in the range of 25.0 M–5.0 mM for quanti-tative analysis of d-glutamine (r2= 0.997) and l-glutamine (r2= 0.991). Moreover, the proposed CLE-CECassay was successfully applied in the kinetics study of glutaminase by using l-glutamine as the substrate.
