High performance liquid chromatography on the chiral stationary phase (R,R)‐DACH‐DNB using carbon dioxide‐based eluents

Abstract

SummaryFast and efficient separations of chiral stereolabile compounds were obtained at very low temperature on a n-acid chiral stationary phase (R,R-DACH-DNB) using carbon dioxide-based mobile phases containing alcoholic polar modifiers.Furthermore, efficient separations of the newly discovered spherical carbon cluster buckminsterfullerene (c60) and the related higher fullerenes (C70, etc.) have been performed on the same stationary phase using eluents based on either n-hexane or carbon dioxide.

The Road to Unified Chromatography: The Importance of Phase Behavior Knowledge in Supercritical Fluid Chromatography and Related Techniques, and a Look at Unification

“…In addition to being able to perform conventional LC with familiar mobile phases, packed-column SFC instruments can easily pump highly volatile liquids (like CO 2 and 1,1,1,2-tetrafluoroethane) while preventing them from boiling, allowing the use of subambient temperatures where stationary phases may provide different selectivities. This has been particularly successful with chiral stationary phases, where temperature as low as Ϫ50°C have been used successfully with CO 2 (10,11). It is thought that such temperatures improve chiral selectivity by increasing order in the stationary phase and also improve separations of enantiomers by slowing the rate of interconversion.…”

Twenty years of research on silica‐based chiral stationary phases

“…Efficient separations of the buckminsterfullerene C 60 and the related higher fullerene C 70 were performed using eluents based on either n-hexane or carbon dioxide [29].…”