Liquid and subcritical CO 2 separations of enantiomers on a broadly applicable polysiloxane chiral stationary phase

Abstract

Incorporation of chiral selector 1 into a polysiloxane which is then immobilized on silica affords chiral stationary phase (CSP 1) capable of resolving a broad array of enantiomers by either high-performance liquid chromatography or supercritical fluid chromatography (SFC). Like its brush-type analog, the commercial version of which is known as the Whelk-O 1, CSP 1, the “polyWhelk-O”, is stable to normal and reversed-phase conditions and to a wide range of temperatures, mobile phases and additives. In most cases, the polyWhelk-O affords greater enantioselectivity and less retention than does the brush-type Whelk-O 1 under the same conditions. An extensive collection of separations of the enantiomers of a variety of types of compounds is presented to illustrate the scope and level of performance typically afforded by the polyWhelk-O columns.