Thermodynamic study on the gas chromatographic separation of the enantiomers of aromatic alcohols using heptakis(2,3-di-O-methyl-6-O-tert- butyldimethylsilyl)-β-cyclodextrin as a stationary phase

Abstract

Gas chromatographic separation of the enantiomers of nineteen structurally related aromatic alcohols was investigated as a function of temperature using a heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-β-cyclodextrin- coated capillary column. Thermodynamic parameters were determined and compared with those obtained with the nonchiral, reference stationary phase, OV-1701. While the -ΔH and -ΔS values for the more retained enantiomers of all nineteen alcohols are comparable on the chiral stationary phase used, the -Δ(ΔH) and -Δ(ΔS) values are considerably different. Of all the solutes tested, enantiodiscrimination was the greatest for the 2,6-difluoro-α-methylbenzyl alcohol. © 2004 Elsevier B.V. All rights reserved.