Application of ionic liquids for permanent silica surface modification in capillary electrophoresis

I&EC 124

Mihkel Koel, vmihkel@chemnet.ee, Maria Borissova, and Mihkel Kaljurand. Institute of Chemistry, Tallinn University of Technology, Akadeemia tee 15, Tallinn, 12618, Estonia
The immobilization of Room Temperature Ionic Liquids on the solid materials as surface coating successfully are employed in capillary electrophoresis. The modified capillary has remarkable benefits: the analyte – silica wall interactions are significantly decreased and the direction of electroosmotic flow can be manipulated by appropriate modifying reagent. Moreover, EOF in coated capillary is more stable and allows higher reproducibility in separation. In the present study imidazole-based ionic liquid has been permanently bounded to capillary wall. The coated capillaries examined for the use with aqueous as well as with non-aqueous electrolytes. The effectiveness of the coating has been investigated by separation of the mixture of phenolic compounds in non-aqueous media and organic acids in aqueous media. Ionic liquids also have been used as components of running electrolyte. The reproducibility of coated capillary in terms of migration time of neutral marker has been evaluated for run-to-run and for day-to-day runs.