Measurements of association constants between enantiomers and chiral selectors by capillary gas chromatography. Theoretical and practical considerations

作者：Lebed Pablo J; Keunchkarian Sonia; Osorio Grisales Jaiver; Castells Cecilia B^*

来源：Journal of Chromatography A, 2014, 1324: 198-206.

DOI：10.1016/j.chroma.2013.11.007

• Chiral gas-liquid chromatography
• Association constants
• Capillary columns
• Octakis(3-O-butanoyl-2,6-di-O-pentyl)-gamma-cyclodextrin

The association constants of several volatile enantiomers with octakis(3-O-butanoyl-2,6-di-O-pentyl)-gamma-cyclodextrin at temperatures between 50 and 100 degrees C were measured by gas-liquid chromatography using capillary columns coated with different amounts of chiral selector dissolved in polysiloxane OV-1701 and prepared with a precisely determined phase ratio. Simple expressions were deduced to estimate the apparent distribution constants from accurate hold-up and retention times along with that known phase ratio at each temperature. The enantiomer-chiral selector association constants were then calculated from the linear regression of the apparent constants as a function of the chiral selector concentration. One aim of this study consisted in discussing all the experimental uncertainties inherent in the determination of enantiomer/selector association constants with chiral analytes, and how these fundamental measurements can be performed precisely without resorting to the use of reference solutes.

• 出版日期2014-1-10