ISOTACHOPHORESIS SUPERIMPOSED ON CAPILLARY ZONE ELECTROPHORESIS

Applying isotachophoresis (ITP) superimposed on capillary zone electrophoresis (CZE), which will be denoted the ITP/CZE mode, components migrate in an ITP way on top of a background electrolyte. In such an ITP/CZE system the leading electrolyte consists of a mixture of an ionic species L1 with a high mobility (the leading ion of the ITP system), an ionic species L2 with low mobility (the co-ions of the ZE system) and buffering counter ions, whereas the terminating solution contains only the ionic species L2 and the buffering counter ions. The zones of the components migrating in the ITP/CZE mode are very sharp owing to the self-correcting effect and the concentrations of the components are adapted to the concentration of the L1 ions of the system. Calculated mobility windows are given, indicating which components can migrate in the ITP/CZE mode and features and possibilities of ITP/CZE are discussed on the basis of several electropherograms.