PERFORMANCE OF ZWITTERIONIC AND CATIONIC FLUOROSURFACTANTS AS BUFFER ADDITIVES FOR CAPILLARY ELECTROPHORESIS OF PROTEINS

In this work, a study has been made of the performance of a zwitterionic fluorosurfactant and mixtures of a zwitterionic and a cationic fluorosurfactant, when-used as buffer additives in capillary electrophoresis. Thus, it showed to be possible to change the direction of the electroosmotic flow by changing the pH of the buffer solution. Possible mechanisms for the behaviour of the electroosmotic flow at different pH and when using different surfactant combinations are suggested. High efficiency separations of some model proteins can be obtained, when a mixture of a cationic and a zwitterionic fluorosurfactant is added to the running buffer solution. By changing concentration proportions between the surfactants, a change in separation selectivity is obtained. This procedure provides an alternative way for selectivity tuning in protein separations by capillary electrophoresis.