capillary isotachophoesis (CITP)

The main feature of CITP is that it is performed in a discontinuous buffer system. Sample components condense between leading and terminating constituents, producing a steady-state migrating configuration composed of conservative sample zones. This mode of operation is therefore different from other modes of capillary electrophoresis, eg CZE, which are normally carried out in a uniform carrier buffer and is characterized by sample zones which continuously change shape and relative position. In the case of a typical CZE separation, the electropherogram obtained contains sample peaks similar to those obtained in chromatographic separations, whereas in the case of CITP, the isotachopherogram obtained contains a series of steps, with each step representing an analyte zone. Unlike in other CE modes, where the amount of sample present can be determined from the area under the peaks as in chromatography, quantitation in CITP is mainly based on the measured zone length which is proportional to the amount of sample present.