Electromigration dispersion in Capillary Electrophoresis

TL;DR

This paper extends the mathematical modeling of solute concentration evolution in capillary electrophoresis to include weak electrolytes, deriving an approximate formula for peak variance that aligns with experimental data.

Contribution

It demonstrates that the nonlinear wave equation also applies to buffers with weak acids or bases, broadening the theoretical framework.

Findings

Derived an approximate formula for peak variance.

Validated the formula against experimental data.

Extended the model to weak electrolytes.

Abstract

In a previous paper (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol. 72, pg. 2047) it was shown that the evolution of the solute concentration in capillary electrophoresis is described by a nonlinear wave equation that reduced to Burger's equation if the nonlinearity was weak. It was assumed that only strong electrolytes (fully dissociated) were present. In the present paper it is shown that the same governing equation also describes the situation where the electrolytic buffer consists of a single weak acid (or base). A simple approximate formula is derived for the dimensionless peak variance which is shown to agree well with published experimental data.