Self-sharpening effect

Constant Pattern, Self-Sharpening Effect, Shock-Layer Theory... 

Equation 10.115 has a considerable fundamental and practical importance. It combines parameters of fimdamentally different origins, the plate number at infinite dilution, N, which characterizes the intensity of axial dispersion taking place in the column and two parameters of thermod5mamic origin, the retention factor at infinite dilution, ICg, related to the initial slope of the isotherm, and the loading factor, proportional to the sample size and related to the saturation capacity of the isotherm. Accordingly, Eq. 10.115 indicates the extent to which the self-sharpening effect on the band profile due to the nonlinear thermodynamics is balanced by the dispersive effect of axial and eddy diffusion and of the mass transfer resistances. 

From the analytical point of view, the concentrating effect of isotachophoresis is of great significance, it allows to analyze minute amounts of ionic components in both electrolytic and non-electrolytic sample mixtures. "The self-sharpening effect causes that the isotachophoretic zone boundaries, having once been formed remain very sharp and do not change with time. This enables even very small amounts of the substances that form very narrow zones to be analyzed. 

Constant composition and constant volume of the zone during the isotachophoretic migration in the steady state permit-to select the time optimum for the given analysis so that the substances with small differences in their mobilities may well be separated from one another. This possibility, together with the self-sharpening effect of the boundary, ensures an efficient separation of the substances to be analyzed. 

CONSTANT PATTERN, SELF-SHARPENING EFFECT, SHOCK-LAYER THEORY... 

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