Isotachophoresis

Abstract

An interesting and specific variant of electrophoresis occurs when the electrophoretic space is filled with a solution of electrolytes which yield one or several common ions upon dissociation. A typical example is a solution of several salts of the same acid or the same base. Under certain conditions in an applied electric field the solution is divided into pure zones of individual ions, and the common ion (the so-called counterion) is present everywhere. In this case, in the stabilized regime the boundaries between zones are sufficiently clear and move at a constant velocity, which is the basis for the name of this method; and the electrolytes to be separated line up in decreasing order of transport rates. In the general case, the order according to transport rates does not coincide with the order according to mobilities (see also [95]).