Chromatography Techniques

Biography

Biography: David Sýkora,

Abstract

The column, the ‘heart’ of the HPLC system, has changed greatly with the development of liquid chromatography. The stationary phases packed in the columns have been improved to provide greater separation speed and efficiency, as well as increased stability and reproducibility. Many new sorbents have been introduced for the extension of HPLC/UHPLC to a wider range of sample types or for better separation of compounds, which have in the past proved problematic. However, there exists still vital interest in new stationary phases possessing different separation selectivity or providing an improved separation with respect to commercially available columns. In addition, new techniques of stationary phase synthesis are continuously searched and proposed for their potential to provide novel stationary phases more easily or with some other benefit. In our work, eight different stationary phases based on two aminopropyl silicas of different brands suitable for multimodal chromatography applications have been prepared by a four-component Ugi reaction. Our intention was to synthesize stationary phases significantly differing in their properties, thereby demonstrating flexibility of the Ugi synthetic protocol. Diverse functional groups including a nonpolar long aliphatic chain, a phenyl moiety, a cholic acid scaffold, phenylboronic and monosaccharide units, charged betaine, and arginine moieties were immobilized on a silica surface. The novel sorbents were extensively characterized by a wide variety of analytical techniques, including elemental analysis, Raman spectroscopy, and chromatography. Considering the anchored chemical structures covalently bonded to the silica surface, reversed-phase, hydrophilic, and ion-exchange separation modes were expected. The chromatographic evaluation was performed to map the potential of the individual columns specifically in the mentioned chromatographic modes.