MULTICHANNEL FLOW ELECTROPHORESIS IN AN ALTERNATING ELECTRIC-FIELD

Investigation on the mass transfer behavior of multichannel flow elect rophoresis (MFE) has confirmed the existence of concentration polariza tion in the separation process, which is characterized by a reduction of the relative protein migration flux corresponding to an increase in the protein concentration in the feed. The mobility of bovine serum a lbumin (BSA) in a gel membrane, as interpreted from its elution curve, was about one-sixth of its mobility in solution as determined by high capillary electrophoresis. This indicates that accumulation of charge d protein onto the membrane surface occurs in MFE. An alternating elec tric field was applied instead of the steady one in MFE. The negative part of the alternating electric field reduced the polarization layer periodically. The effectiveness of this method was demonstrated by an over 40% increase of BSA migration flux at pH 6.9 in an optimized alte rnating electric field. The separation outputs of BSA and hemoglobin b ovine blood conducted in an optimized alternating electric field at pH 6.0 were about 26 and 32% higher than their respective outputs obtain ed in a steady electric field. Because of its proven efficiency for re ducing concentration polarization and its ease of operation, the use o f an alternating electric field is a promising application in other me mbrane separation processes.