When van Deemter Goes Upside Down in Chiral Chromatography

The occurrence of convex-upward van Deemter curves is rare but not unusual in chiral liquid chromatography (LC). In this article, this behaviour, experimentally observed for the more retained enantiomer of a chiral sulfoxide on a polysaccharide-based chiral stationary phase (CSP), has been investigated from an experimental viewpoint, finding that this species is characterized by a very strong, localized adsorption on the CSP. The observation of the behaviour of other chiral sulfoxides with different chemical structures has suggested correlations between molecular properties and specific interactions on the CSP.