Interaction of Electroosmotic Flow on Isotachophoretic Transport of Ions
A numerical study on the influence of electroosmotic flow on analyte preconcentration by isotachophoresis ( ITP) is made. We consider that the double layer induced electroosmotic flow ( EOF) counterbalance the electrophoretic velocity and a stationary ITP stacked zones results. We solve the Navier-Stokes equations coupled with the Nernst-Planck equations to determine the local convective velocity and the preconcentration dynamics of ions. Our numerical algorithm is based on a finite volume method along with a secondorder upwind scheme. The present numerical algorithm can capture the the sharp boundaries of step-changes ( plateau mode) or zones of steep gradients ( peak mode) accurately. The convection of ions due to EOF reduces the resolution of the ITP transition zones and produces a dispersion in analyte zones. The role of the electrokinetic parameters which induces dispersion is analyzed. A one-dimensional model for the area-averaged concentrations based on the Taylor-Aristype effective diffusivity is found to be in good agreement with the computed solutions.
[1] Kohlrausch, F., Ueber Concentrations-Verschiebungen durch Electrolyse
im Inneren von L¨osungen und L¨osungsgemischen, Ann. Physik 62,
209(1897).
[2] Chen, L., Prest, J. E., Fielden, P. R., Goddard, N. J., Manz, A., and Day,
P. J. R., Miniaturized isotacophoresis analysis, Lab-on-a-Chip, 6(2006),
474-487.
[3] Gebauer, P., Mal'a, Z., and Boˇcek, P., Recent progress in analytical
capillary isotachophoresis, Electrophoresis, 32, 83(2011).
[4] Garcia-Schwarz, G., Bercovici, M., Marshall, L. A., and Santiago, J.
G., Sample dispersion in isotachophoresis, Journal of Fluid Mechanics
2011, 679, 455-475.
[5] Bercovici, M., Lelea, S.K., Santiago, J. G., Compact adaptive-grid
scheme for high numerical resolution simulations of isotachophoresis,
Journal of Chromatography A, 1217, 588-599(2010).
[6] Hruska, V., Jaros, M., Gas, B., Simul 5 Free dynamic simulator of
electrophoresis, Electrophoresis 27, 984-991(2006).
[7] Yu, J. W., Chou, Y., Yang, R. J., High-resolution modeling of isotachophoresis
and zone electrophoresis, Electrophoresis, 29, 1048-
1057(2008).
[8] Chou, Y., Yang, R. J., Numerical solutions for isoelectric focusing and
isotachophoresis problems, Journal of Chromatography A, 1217, 394-
404(2010).
[9] Bercovici, M., Lelea, S.K., Santiago, J. G., Open source simulation
tool for electrophoretic stacking, focusing, and separation, Journal of
Chromatography A, 1216, 1008-1018 (2009).
[10] Thormann, W., Breadmore, M.C., Caslavska, J., and Mosher, R.A.,
Dynamic Computer Simulations of Electrophoresis: A versatile Research
and Teaching Tool, Electrophoresis, 31, 726-754 (2010).
[11] Khurana, T. K., and Santiago, J. G., Preconcentration, Separation,
and Indirect Detection of Nonfluorescent Analytes Using Fluorescent
Mobility Markers, Anal. Chem. 80 (2008) 279-286.
[12] Shim, J., Dutta, P. and Ivory, C. F., Finite-volume methods for Isotachophoretic
seperation in microchannels Numerical Heat Transfer, Part
A: Applications, 52, 441-461(2007).
[13] Choi, H., Jeon, Y., Cho, M., Lee D., and Shim, J., Effects of crosssectional
change on the isotachophoresis process for protein-seperation
chip design, Microsyst Technol 16, 1931-1938(2010).
[14] D. A. Saville, The effects of electroosmosis on the structure of isota
chophoresis boundaries, Electrophoresis 11, 899-902(1990.
[15] F. Sch¨onfeld, G. Goet, T. Baier,and S. Hardt, Transition zone dynamics
in combined isotachophoretic and electro-osmotic transport, Physics of
Fluids 21, 092002(2009).
[16] Baier, T., Sch¨onfeld, F., and Hardt, S., Analytical approximations to the
flow field induced by electroosmosis during isotachophoretic transport
through a channel, J. Fluid Mech. 682, 101-119(2011).
[17] Fletcher, C. A. J., Computation Technique for Fluid Dynamics. (1998)
vol 2. Springer, Berlin.
[18] Goet, G., Baier, T., and Hardt, S., Transport and separation of micron
sized particles at isotachophoretic transition zones, Biomicrofluidics, 5
(2011) 014109.
[19] D. A. MacInnes and L. G. Longsworth, Transference Numbers by the
Method of Moving Boundaries, Chem. Rev. 11(1932) 171-230.
[1] Kohlrausch, F., Ueber Concentrations-Verschiebungen durch Electrolyse
im Inneren von L¨osungen und L¨osungsgemischen, Ann. Physik 62,
209(1897).
[2] Chen, L., Prest, J. E., Fielden, P. R., Goddard, N. J., Manz, A., and Day,
P. J. R., Miniaturized isotacophoresis analysis, Lab-on-a-Chip, 6(2006),
474-487.
[3] Gebauer, P., Mal'a, Z., and Boˇcek, P., Recent progress in analytical
capillary isotachophoresis, Electrophoresis, 32, 83(2011).
[4] Garcia-Schwarz, G., Bercovici, M., Marshall, L. A., and Santiago, J.
G., Sample dispersion in isotachophoresis, Journal of Fluid Mechanics
2011, 679, 455-475.
[5] Bercovici, M., Lelea, S.K., Santiago, J. G., Compact adaptive-grid
scheme for high numerical resolution simulations of isotachophoresis,
Journal of Chromatography A, 1217, 588-599(2010).
[6] Hruska, V., Jaros, M., Gas, B., Simul 5 Free dynamic simulator of
electrophoresis, Electrophoresis 27, 984-991(2006).
[7] Yu, J. W., Chou, Y., Yang, R. J., High-resolution modeling of isotachophoresis
and zone electrophoresis, Electrophoresis, 29, 1048-
1057(2008).
[8] Chou, Y., Yang, R. J., Numerical solutions for isoelectric focusing and
isotachophoresis problems, Journal of Chromatography A, 1217, 394-
404(2010).
[9] Bercovici, M., Lelea, S.K., Santiago, J. G., Open source simulation
tool for electrophoretic stacking, focusing, and separation, Journal of
Chromatography A, 1216, 1008-1018 (2009).
[10] Thormann, W., Breadmore, M.C., Caslavska, J., and Mosher, R.A.,
Dynamic Computer Simulations of Electrophoresis: A versatile Research
and Teaching Tool, Electrophoresis, 31, 726-754 (2010).
[11] Khurana, T. K., and Santiago, J. G., Preconcentration, Separation,
and Indirect Detection of Nonfluorescent Analytes Using Fluorescent
Mobility Markers, Anal. Chem. 80 (2008) 279-286.
[12] Shim, J., Dutta, P. and Ivory, C. F., Finite-volume methods for Isotachophoretic
seperation in microchannels Numerical Heat Transfer, Part
A: Applications, 52, 441-461(2007).
[13] Choi, H., Jeon, Y., Cho, M., Lee D., and Shim, J., Effects of crosssectional
change on the isotachophoresis process for protein-seperation
chip design, Microsyst Technol 16, 1931-1938(2010).
[14] D. A. Saville, The effects of electroosmosis on the structure of isota
chophoresis boundaries, Electrophoresis 11, 899-902(1990.
[15] F. Sch¨onfeld, G. Goet, T. Baier,and S. Hardt, Transition zone dynamics
in combined isotachophoretic and electro-osmotic transport, Physics of
Fluids 21, 092002(2009).
[16] Baier, T., Sch¨onfeld, F., and Hardt, S., Analytical approximations to the
flow field induced by electroosmosis during isotachophoretic transport
through a channel, J. Fluid Mech. 682, 101-119(2011).
[17] Fletcher, C. A. J., Computation Technique for Fluid Dynamics. (1998)
vol 2. Springer, Berlin.
[18] Goet, G., Baier, T., and Hardt, S., Transport and separation of micron
sized particles at isotachophoretic transition zones, Biomicrofluidics, 5
(2011) 014109.
[19] D. A. MacInnes and L. G. Longsworth, Transference Numbers by the
Method of Moving Boundaries, Chem. Rev. 11(1932) 171-230.
@article{"International Journal of Engineering, Mathematical and Physical Sciences:51872", author = "S. Bhattacharyya and Partha P. Gopmandal", title = "Interaction of Electroosmotic Flow on Isotachophoretic Transport of Ions", abstract = "A numerical study on the influence of electroosmotic flow on analyte preconcentration by isotachophoresis ( ITP) is made. We consider that the double layer induced electroosmotic flow ( EOF) counterbalance the electrophoretic velocity and a stationary ITP stacked zones results. We solve the Navier-Stokes equations coupled with the Nernst-Planck equations to determine the local convective velocity and the preconcentration dynamics of ions. Our numerical algorithm is based on a finite volume method along with a secondorder upwind scheme. The present numerical algorithm can capture the the sharp boundaries of step-changes ( plateau mode) or zones of steep gradients ( peak mode) accurately. The convection of ions due to EOF reduces the resolution of the ITP transition zones and produces a dispersion in analyte zones. The role of the electrokinetic parameters which induces dispersion is analyzed. A one-dimensional model for the area-averaged concentrations based on the Taylor-Aristype effective diffusivity is found to be in good agreement with the computed solutions.
", keywords = "Interfaces, Electroosmotic flow, QUICK Scheme,
Dispersion, Effective Diffusivity.", volume = "6", number = "9", pages = "1253-7", }
