Enantioseparation of Hydrobenzoin and Structurally Related Compounds on β-Cyclodextrin and Hydroxypropyl-β-cyclodextrin Bonded Chiral Stationary Phases

A beta-cyclodextrin (beta-CD) and a hydroxypropyl-beta-cyclodextrin (HP-beta-CD) bonded chiral stationary phase (CSP) were prepared. Comparative evaluations of these two CSPs for the enantioseparation of hydrobenzoin, benzoin and alpha-phenethyl alcohol by reversed-phase liquid chromatography were presented. The effects of buffer composition in the mobile phase on the retention and enantioseparation were investigated. The borate buffer had a significant influence on the retention and enantioseparation of hydrobenzoin. Linear solvent strength retention model was used to fit the chromatographic data. Good linearity existed between the logarithm of retention factor (k) and the volume fraction of organic modifier (phi). Another retention model, stoichiometric displacement theory for retention, was also tried to fit the chromatographic data. The results showed that not only acetonitrile, but also water molecules participated in the displacing process of the solute.