Enantiomeric separation of 8 hydroxy, 10 carboxylic and 6 dansyl amino acids by mono(6-amino-6-deoxy)-β-cyclodextrin in capillary electrophoresis

The enantioseparation of a wide spectrum of anionic analytes was successfully performed by using mono(6-amino-6-deoxy)-β-cyclodextrin (β-CD-NH2). The effects of buffer pH and selector concentration on migration time and resolution of analytes were studied in detail. Good results were obtained for the chiral separations of hydroxy and carboxylic acids. A clear maximum in selectivity was found for most analytes. The introduced positive charge can greatly improve the chiral recognition ability of β-CD-NH2 towards anionic analytes. The binding constants of eight analytes with β-CD-NH2 were determined and suited well with the mobility difference model (by Wren). Moreover, a standard mixture of five acids was baseline separated within 23 min.