Electrically driven capillary size exclusion chromatography

Electrically driven size exclusion chromatography (ED-SEC) of polystyrenes in packed capillaries using dimethylformamide as solvent is demonstrated. T he efficiency and retention behaviour of polystyrenes under pressure and el ectro drive were investigated. Under pressure drive the plate height (H) in creases steadily with increasing linear velocity (u) whereas under electro drive the H-u curves largely coincide and are very flat. At higher velociti es the plate heights are about 50 % smaller with electro drive than with pr essure drive. Calculations show that with increasing ionic strength, the fl ow through the particles may increase causing a clear diminishing of the el ution window.