Isotachophoresis superimposed on capillary zone electrophoresis

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