Description of project


Capillary electrochromatography (CEC) represents a separation technique which combines features of chromatography and electrophoresis in a unique way. Like in chromatography analytes are resolved based on the interaction with a stationary phase; yet, the mobile phase is transported through the system not by pressure but by the electroosmotic flow, one of the principles of electrophoresis. This signature combination of two separation modes results in many theoretical advantages in terms of separation efficiency and selectivity. The principles of CEC were described more than 30 years ago, and studies regarding the underlying separation mechanisms and the preparation of suitable stationary phases conducted. Even so, up to now CEC is not really relevant in routine analysis because of two reasons; first, only a few convincing applications have been reported, and second, possibly because of that CEC-capillaries are hardly commercially available.

This research proposal intends to bridge this apparent discrepancy between many desired features of CEC and the (assumed) limited practical relevance of this technique. The last few years brought advancement particularly regarding the fabrication of novel stationary phases (e.g. use of polymermonoliths, surface modifications by nanoparticles, innovative monomers like silsesquioxanes), materials which either haven’t left developmental stage or whose practical relevance never has been evaluated. Accordingly, in this project these innovative stationary phases will be utilized and optimized for the analysis of complex matrices by CEC. The latter comprises the determination of natural products (e.g. flavonoids, alkaloids or phenolic acids) in plant extracts, truly challenging samples for any separation technique. By such a targeted approach the dormant potential of CEC, an extremely powerful and versatile analytical technique will hopefully be recognized at last.