Isotachophoresis description

One of the major advantages of CE as a separation technique is the wide variety of separation modes available. Analytes can be separated on the basis of charge, molecular size or shape, pi, or hydrophobicity. The same CE instrument can be used for zone electrophoresis, IEF, sieving separations, isotachophoresis, and chromatographic techniques such as MEKC and capillary electrokinetic chromatography. This section provides a brief description of each separation mode. Zone electrophoresis, IEF, and sieving are the primary modes used for protein separations, and these will be discussed in detail in the following sections. 

Moreover, such a description requires the definition of resolution in isotachophoresis and shows the result that can be expected from optimalization procedures. In electrophoresis the migration velocity, V, of a constituent, i, is given by the product of effective mobility, m, and the local field strength, E. 

The preceding solution of the electrolyte transport equations was derived for strong electrolytes. Solving these equations in an explicit form for weak electrolyte systems is practically impossible. However, for the description of the steady-state migration, even in such a case, an approach can be adopted successfully where the relationships valid for isotachophoresis are applied to elementary formulated equations of the mass balance, the density of electric current and the electroneutrality in isotachophoretic zones. 

The present state of the instrumentation used for analytical isotachophoresis can be characterized by the fact that both commercial devices " and fairly advanced home-made devices are being used for analytical and preparative purposes. (For a description see 2.53,61.69) ... 

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