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

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.