Electrically driven capillary size exclusion chromatography

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