Kinetic Capillary Electrophoresis

In sSweepCE, a short plug of T is injected into the capillary prefilled with L. Both inlet and outlet reservoirs contain the run buffer. T moves through L during electrophoresis causing both association of T and L and dissociation of resulting C to occur. The concentration profiles of T and C are peaklike, while that of L is a smooth function.

In SweepCE, the capillary is filled with L, while the inlet reservoir contains T and the outlet reservoir contains a run buffer. During electrophoresis, T continuously moves through L, causing continuous binding of T to L. Although binding is a prevalent process in SweepCE, dissociation of C can also contribute to the resulting concentration profiles, which contain a single peak of C and plateaus of T and L.

In ppKCE, the plugs of L and T are injected into the capillary prefilled with the run buffer. The inlet and outlet reservoirs contain the run buffer as well. During electrophoresis T moves through L causing the formation of L. When the zone of T passes L, C starts to dissociate. ppKCE can be considered as a functional hybrid of NECEEM and sSweepCE. The resulting concentration profiles resemble those of NECEEM with a smaller peak of C and “smears” of T and L.

In NECEEM, a short plug of the equilibrium mixture is injected into the inlet of the capillary, which is prefilled with the run buffer. Separation is carried out with both inlet and outletreservoirs containing the run buffer only. C continuously dissociates during electrophoresis. If separation is efficient, reassociation of T and L can be neglected. The resulting concentration profiles (time dependencies of concentrations for a fixed x) contain three peaks of T, C, and L and two exponential “smears” of L and T, which occur from the dissociation of C.

Reference Petrov, A.; Okhonin, V.; Berezovski, M.; Krylov, S.N. Kinetic capillary electrophoresis (KCE): a conceptual platform for kinetic homogeneous affinity methods. Journal of the American Chemical Society 2005, 127, 17104-17110. (PDF file)