THEORY OF SOLITARY WAVES IN ELECTROPHORESIS

A theoretical study about the generation of solitary waves (SW) in ele ctrophoresis and capillary electrophoresis is performed. Two models th at use velocity terms in Fick's first law and absorption and decaying terms in Fick's second law are presented. These models give the time e volution of the band or zone shape in electrophoresis and capillary el ectrophoresis in the presence of electromagnetic radiation. In particu lar, the effect of electrophoretic mobility changes of the analytes du e to radiation excitation is included in the present models. The analy tes are represented either by three-level or four-level systems. It is shown that the resulting system of coupled nonlinear partial differen tial equations governing the spatial motion of these bands over time e xhibits SW solutions for some values of the equation parameters. We an alyze the conditions in which these SWs, which propagate with constant velocity, constant area, constant standard deviation, and without cha nge of form, are generated. The results of the present models are comp ared with those from a previous two-level model (Phys. Rev. Lett. 1995 , 75, 1210-1213). The velocities of these SWs are calculated analytica lly. The time evolution of their standard deviations is shown. The num erical integration of a two-component electrophoresis run shows higher resolutions under some conditions. The expected practical difficultie s which may be encountered when observing this phenomenon are discusse d. Some practical difficulties that are likely to limit its useful app lication in electrophoresis and capillary electrophoresis are mentione d.