The degree of substitution affects the enantioselectivity of sulfobutylether-beta-cyclodextrin chiral stationary phases
Abstract
Three chiral stationary phases were prepared by dynamic coating of sulfobutylether-beta-cyclodextrin (SBE-beta-CD) with different degrees of substitution, onto strong anion-exchange stationary phases. The enantioselective potential and stability of newly prepared chiral stationary phases were examined using a set of structurally different chiral analytes.
Measurements were performed in RP-HPLC. Mobile phases consisted of methanol/formic acid, pH 2.10, and methanol/10 mM ammonium acetate buffer, pH 4.00, in various volume ratios.
SBE-beta-CDs with degrees of substitution (DS) 4, 6.3, and 10 proved suitable for the enantioseparation of 14, 11, and 8 analytes, respectively. The SBE-beta-CD DS 4 based chiral stationary phase enabled the enantioseparation of the nearly all basic and neutral compounds.
Chiral stationary phases with higher sulfobutylether-beta-cyclodextrin substitution (especially DS 10) yielded higher enantioresolution values for acidic compounds.