Artículos de revistas
Measurements of association constants between enantiomers and chiral selectors by capillary gas chromatography. Theoretical and practical considerations
Fecha
2014-01Registro en:
Lebed, Pablo Jorge; Keunchkarian, Sonia; Osorio Grisales, Jaiver; Castells, Cecilia Beatriz Marta; Measurements of association constants between enantiomers and chiral selectors by capillary gas chromatography. Theoretical and practical considerations; Elsevier Science; Journal Of Chromatography - A; 1324; 1-2014; 198-206
0021-9673
Autor
Lebed, Pablo Jorge
Keunchkarian, Sonia
Osorio Grisales, Jaiver
Castells, Cecilia Beatriz Marta
Resumen
The association constants of several volatile enantiomers with octakis(3-O-butanoyl-2,6-di-O-pentyl)-γ-cyclodextrin at temperatures between 50 and 100 °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.