Dynamic control to improve the separation performance in capillary electrophoresis

Dynamic control in capillary electrophoresis (CE) is able to provide better resolution, shorter separation time, reduced band broadening and better reproducibility for the separations of organic and inorganic ions and large molecules such as proteins and DNA. This article provides an overview of dynamic control in CE by several techniques: pH, temperature, external electric field, and field amplification. These techniques take advantage of the changes in electroosmotic flow coefficient, electrophoretic mobilities of the analytes due to changes in equilibrium, viscosity of the buffer solution, and/or electric field strength. The basic theories and applications to the improvement of the separation performance for standard samples in CE by using these dynamic control techniques are presented. Finally, the advantages and shortcomings of these techniques and the future trends of dynamic control for the separations of real samples are discussed.