The dynamics of band (peak) shape development in capillary zone electrophoresis in the case of two co‐migrating analytes: The displacement and the tag‐along effects

Abstract

The dynamics of band (peak) shape development in capillary zone electrophoresis in the case of two co-migrating analytes: The displacement and the tag-along effects Peak shapes in electrophoresis are often distorted from the ideal Gaussian shape due to disturbing phenomena, of which the most important is electromigration dispersion. For fully dissociated analytes, there is a tight analogy between nonlinear models describing a separation process in chromatography and electrophoresis. When the velocity of the separated analyte depends on the concentration of the co-analyte, the consequence is a mutual influence of the analytes couples, which distorts both analyte zones. In this paper, we introduce a nonlinear model of electromigration for the analysis of two co-migrating fully dissociated analytes. In the initial stages of separation, they influence each other, which causes much more complicated peak shapes. The analysis has revealed that the two most important phenomena-the displacement and the tag-along effects-are common both for nonlinear chromatography and electrophoresis, though their description is partly based on rather different phenomena. The comparison between the nonlinear model of electromigration we describe and the numerical computer solution of the original continuity equations has proven an almost perfect agreement. The predicted features in peak shapes in initial stages of separation have been fully confirmed by the experiments.

Dynamic computer simulations of electrophoresis: 2010–2020

“…Comparison of simulation and experimental data of ITP systems provided the insight that the EOF can be estimated with an ionic strength‐dependent model similar to that previously used to describe EOF in fused‐silica capillaries dynamically double coated with Polybrene and poly(vinylsulfonate) [ 133 ]. SIMUL5 was employed to provide a comparison of peak shapes predicted by simulation with those of a new nonlinear model of electromigration for the analysis of two co‐migrating fully dissociated analytes [ 134 ]. For the systems studied, an almost perfect agreement was obtained.…”

System eigenmobilities in zone electrophoresis: A general moving‐boundary approach

“…Systems of this kind allow considerable simplifications of the model and are used to describe properties of electrophoretic systems since the beginnings of electrophoresis, including the fundamental works by Kohlrausch [21] and Weber [22]. Although it could seem that properties of systems containing only strong electrolytes represent a rather academic problem as they appear very scarcely in practice, the benefits of this level of simplification are so significant that they remain being used as the base of various theoretical models up to modern times (e.g., [15,[23][24][25]).…”