A phenylcarbamate derivative of 2-hydroxypropyl-β-CD bonded stationary phase was prepared by a previously described method. Its enantiomeric recognition abilities were evaluated as chiral stationary phase (CSP) in normal, polar organic and RP conditions by HPLC. The relevant structural features of the prepared stationary phase which make it an effective chiral selector are discussed. This material seems to have an excellent enantioselectivity for a variety of racemic analytes in the three modes. Hence it can be considered a highly effective multimodal column. Retention factor (k), selectivity (α) and resolution (Rs) were the chosen parameters to describe the column performance. Optimization of these separations was discussed in terms of mobile phase composition, flow rate and structural patterns of the injected analytes.

Preparation and chromatographic properties of a multimodal chiral stationary phase based on phenyl‐carbamate‐propyl‐β‐CD for HPLC

Two chiral stationary phases for high-performance liquid chromatography (HPLC) have been synthesized by grafting native and 2-hydroxypropyl-β-cyclodextrin onto silica gel by a previously described method. They were tested under reversed-phase conditions. These two materials enable separation of the enantiomers of a variety of drugs (benzodiazepine anxiolytics, arylpropionic acids, anti-inflammatory and anticoagulant agents) and herbicides (aryloxyphenoxypropionic esters). Both chiral stationary phases enabled good chiral recognition in reversed-phase mode. The effects of the nature and composition of the mobile phase, of compound structure (mechanisms of chiral discrimination), and of flow-rate were studied.

Application of Native and Hydroxypropyl-Substituted β-Cyclodextrin Bonded Silica Gel as Stationary Phases for High Performance Liquid Chromatography

Preparation and chromatographic evaluation of a chiral stationary phase based on carboxymethyl-β-cyclodextrin for high-performance liquid chromatography

Cyclodextrins (CDs) and CD derivatives are versatile chiral selectors. They have played a fundamental role in almost every enantiomeric separation and characterization method. In this chapter, an overview of CD-mediated enantiomeric separation methods will be provided, with an emphasis on high-performance liquid chromatography (HPLC), gas chromatography (GC), and capillary electrophoresis (CE), which are the three most important analytical techniques for the separation of enantiomers. A general introduction to CDs and their properties will be presented. In the following section, binding chemistries, categories of CD-bonded stationary phases for HPLC, and their general separation mechanisms will be discussed. In the third part on GC, the main types of CD-based chiral selectors, their separation mechanism in the gas phase, and their applications will be discussed. The last section is focused on CD-mediated enantiomeric separation in CE. An introduction to the four main classes of CDs that are used as chiral additives, as well as their use, effectiveness, and limitations is provided.

8.10 Chromatographic Separations and Analysis: Cyclodextrin Mediated HPLC, GC and CE Enantiomeric Separations

Enantiomeric Separation of Chiral Pesticides by Permethylated β-Cyclodextrin Stationary Phase in Reversed Phase Liquid Chromatography.

The direct HPLC resolution of four structurally related compounds, the Wieland‐Miescher ketone, its C(5) homologue, and their C(1) dioxolane derivatives, was studied on commercially available polysaccharide‐based chiral stationary phases (CSPs) cellulose tris‐(3,5‐dimethylphenylcarbamate) (Chiralcel OD‐H), native β‐cyclodextrin (Cyclobond I), and acetylated, carboxymethylated and permethylated β‐cyclodextrins. The retention, resolution, and elution sequence of the enantiomeric couples were compared using different mobile phases. Baseline enantioseparation of all examined compounds was achieved only on the carboxymethyl‐derivatized β‐cyclodextrin stationary phase that appeared the most effective chiral selector for this class of compounds. Native, acetylated‐, and permethylated‐β‐cyclodextrin CSPs exhibited specific selectivity providing, in general, partial resolution of the compounds under investigation. On Chiralcel OD‐H, only two enantiomeric couples were fully separated. Elution orders depend...

Massimo Sinibaldi

Papers

Chiral HPLC Resolution of the Wieland–Miescher Ketone and Derivatives