Further study on the use of uncharged ?-cyclodextrin polymer in capillary electrophoresis: Enantiomeric separation of some ?-hydroxy acids

Uncharged ?-cyclodextrin polymer was used as chiral selector for the enantiomeric separation of some ?-hydroxy acids by capillary electrophoresis. Complexation and enantiomeric resolution of mandelic acid, m-hydroxy and p-hydroxymandelic acid, 3,4-dihydroxymandelic acid, as well as 2- and 3-phenyllactic acid were studied, changing the concentration of the ?-cyclodextrin polymer added to the background electrolyte at different pH in the range of 4.5-7. Furthermore, the effects of the concentration of the background electrolyte, column temperature, and applied voltage on chiral resolution were also examined. The best enantiomeric separations were obtained using a background electrolyte at pH 6 containing 100 mg/mL of ?-cyclodextrin polymer