Authors: S. Krishnamoorthy, J.J. Feng and V.B. Makhijani
Affilation: CFD Research Corporation, United States
Pages: 206 - 209
Keywords: electrophoresis, ionization, microfluidics, CFD-ACE+, stacking
An implicit finite-volume numerical scheme has been developed to solve the three-dimensional transport equations along with fully-coupled ionization equilibria in acid/base systems. The scheme solves conservation equations for mass and momentum while satisfying the electroneutrality condition in a sequential fashion until convergence is achieved. The electric field is computed based on current conservation formulation. We employ this computational analysis/design tool to study the time evolution of a sample containing several analytes in a capillary electrophoresis microchip. The phenomena of sample stacking and tailing due to conductivity differences and the effect of degree of ionization are analyzed and compared with experimental data of Ermakov and Righetti .