The effect of electric fields on mobile phase migration velocity and on the retention of chromatographed solutes has been investigated for so-called horizontal electric fields with sample applied at the anode and cathode ends of the plates. An electric field can also affect the surfaces of stationary phases. These investigations were performed in a so-called vertical electric field at a gradient voltage 12 kV cm
. The effect of the electric field on the apolar component of the surface free energy was determined for six popular stationary phases; for silica and aluminum oxide it was possible to determine the acidic and basic components of the surface free energy. The effect of electric fields on the zeta potential of silica-methanol and aluminum oxide-water systems was also demonstrated.
, Biochem. J.