Enantiomer separation by capillary electrochromatography on a cyclodextrin-modified monolith

✍ Scribed by Dorothee Wistuba; Volker Schurig

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 157 KB
• Volume: 21
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/1522-2683(20000901)21:15<3152::aid-elps3152>3.0.co;2-l

✦ Synopsis

Enantiomer separation by capillary electrochromatography on a cyclodextrinmodified monolith

A chiral monolithic stationary phase was prepared by packing a capillary with bare porous silica and sintering the silica bed at high temperature. The resulting silica monolith was polymer-coated with Chirasil-Dex, a permethylated b-cyclodextrin covalently linked via an octamethylene spacer to dimethylpolysiloxane. Subsequently, Chirasil-Dex was thermally immobilized on the silica support and a chiral monolith of very high stability (30 kV, more than 400 bar pressure) was obtained. The enantiomer separation of various chiral compounds by monolithic (rod) capillary electrochromatography (rod-CEC) was feasible. This method was compared with capillary liquid chromatography (LC) in a single-column mode using unified equipment. About two to three times higher efficiency was found in the rod-CEC mode as compared to rod-LC. The influence of pressure-driven flow support on efficiency, resolution, elution time and baseline stability was investigated. The amount and nature of organic modifier strongly influences efficiency and resolution.