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  • Journal of Fluid Mechanics, Volume 679
  • July 2011, pp. 455-475

Sample dispersion in isotachophoresis

  • G. GARCIA-SCHWARZ (a1), M. BERCOVICI (a2), L. A. MARSHALL (a3) and J. G. SANTIAGO (a1)
  • DOI:
  • Published online: 12 May 2011

We present an analytical, numerical and experimental study of advective dispersion in isotachophoresis (ITP). We analyse the dynamics of the concentration field of a focused analyte in peak mode ITP. The analyte distribution is subject to electromigration, diffusion and advective dispersion. Advective dispersion results from strong internal pressure gradients caused by non-uniform electro-osmotic flow (EOF). Analyte dispersion strongly affects the sensitivity and resolution of ITP-based assays. We perform axisymmetric time-dependent numerical simulations of fluid flow, diffusion and electromigration. We find that analyte properties contribute greatly to dispersion in ITP. Analytes with mobility values near those of the trailing (TE) or leading electrolyte (LE) show greater penetration into the TE or LE, respectively. Local pressure gradients in the TE and LE then locally disperse these zones of analyte penetration. Based on these observations, we develop a one-dimensional analytical model of the focused sample zone. We treat the LE, TE and LE–TE interface regions separately and, in each, assume a local Taylor–Aris-type effective dispersion coefficient. We also performed well-controlled experiments in circular capillaries, which we use to validate our simulations and analytical model. Our model allows for fast and accurate prediction of the area-averaged sample distribution based on known parameters including species mobilities, EO mobility, applied current density and channel dimensions. This model elucidates the fundamental mechanisms underlying analyte advective dispersion in ITP and can be used to optimize detector placement in detection-based assays.

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R. A. Alberty 1950 Moving boundary systems formed by weak electrolytes. Theory of simple systems formed by weak acids and bases. J. Am. Chem. Soc. 72 (6), 23612367.

J. L. Anderson & W. K. Idol 1985 Electroosmosis through pores with nonuniformly charged walls. Chem. Engng Commun. 38 (3), 93.

R. Aris 1956 On the dispersion of a solute in a fluid flowing through a tube. Proc. R. Soc. Lond. A 235 (1200), 6777.

S. S. Bahga , M. Bercovici & J. G. Santiago 2010 Ionic strength effects on electrophoretic focusing and separations. Electrophoresis 31 (5), 910919.

C.-H. Chen , H. Lin , S. K. Lele & J. G. Santiago 2005 Convective and absolute electrokinetic instability with conductivity gradients. J. Fluid Mech. 524, 263303.

P. Gebauer , Z. Malá & P. Boček 2007 Recent progress in capillary ITP. Electrophoresis 28 (1–2), 2632.

S. Ghosal 2002 Band broadening in a microcapillary with a stepwise change in the zeta-potential. Anal. Chem. 74 (16), 41984203.

A. E. Herr , J. I. Molho , J. G. Santiago , M. G. Mungal , T. W. Kenny & M. G. Garguilo 2000 Electroosmotic capillary flow with nonuniform zeta potential. Anal. Chem. 72 (5), 10531057.

T. Hirokawa , M. Nishino , N. Aoki , Y. Kiso , Y. Sawamoto , T. Yagi & J. I Akiyama 1983 Table of isotachophoretic indices. I. Simulated qualitative and quantitative indices of 287 anionic substances in the range pH 3–10. J. Chromatogr. A 271 (2), D1D106.

M. Jaroš , V. Hruška , M. Štědrỳ , I. Zusková & B. Gaš 2004 Eigenmobilities in background electrolytes for capillary zone electrophoresis. IV. Computer program peakmaster. Electrophoresis 25 (18–19), 30803085.

T. M. Jovin 1973 Multiphasic zone electrophoresis. I. Steady-state moving-boundary systems formed by different electrolyte combinations. Biochemistry 12 (5), 871879.

T. K. Khurana & J. G. Santiago 2008 Sample zone dynamics in peak mode isotachophoresis. Anal. Chem. 80 (16), 63006307.

T. K Khurana & J. G. Santiago 2009 Effects of carbon dioxide on peak mode isotachophoresis: simultaneous preconcentration and separation. Lab Chip 9 (10), 13771384.

B. J. Kirby & E. F. Hasselbrink 2004 Zeta potential of microfluidic substrates. 1. Theory, experimental techniques, and effects on separations. Electrophoresis 25 (2), 187202.

F. Kohlrausch 1897 Über concentrations-verschiebungen durch electrolyse im inneren von lösungen und lösungsgemischen. Ann. Phys. 298 (10), 209239.

H. Lin , B. D. Storey , M. H. Oddy , C.-H. Chen & J. G. Santiago 2004 Instability of electrokinetic microchannel flows with conductivity gradients. Phys. Fluids 16 (6), 1922.

D. A. MacInnes & L. G. Longsworth 1932 Transference numbers by the method of moving boundaries. Chem. Rev. 11 (2), 171230.

A. J. P. Martin & F. M. Everaerts 1970 Displacement electrophoresis. Proc. R. Soc. Lond. A 316 (1527), 493514.

M. M. Martin & L. Lindqvist 1975 The pH dependence of fluorescein fluorescence. J. Lumin. 10 (6), 381390.

N. O. Mchedlov-Petrossyan , V. I. Kukhtik & V. I. Alekseeva 1994 Ionization and tautomerism of fluorescein, rhodamine b, n, n-diethylrhodol and related dyes in mixed and nonaqueous solvents. Dyes Pigment. 24 (1), 1135.

A. Persat & J. G. Santiago 2009 Electrokinetic control of sample splitting at a channel bifurcation using isotachophoresis. New J. Phys. 11 (7), 075026.

R. F. Probstein 1994 Physicochemical Hydrodynamics: An Introduction. Wiley-Interscience.

J. G. Santiago 2001 Electroosmotic flows in microchannels with finite inertial and pressure forces. Anal. Chem. 73 (10), 23532365.

J. J. Santos & B. D. Storey 2008 Instability of electro-osmotic channel flow with streamwise conductivity gradients. Phys. Rev. E 78 (4), 46316.

D. A. Saville 1990 The effects of electroosmosis on the structure of isotachophoresis boundaries. Electrophoresis 11 (11), 899902.

D. A. Saville & O. A. Palusinski 1986 Theory of electrophoretic separations. Part I. Formulation of a mathematical model. AIChE J. 32 (2), 207214.

F. Schönfeld , G. Goet , T. Baier & S. Hardt 2009 Transition zone dynamics in combined isotachophoretic and electro-osmotic transport. Phys. Fluids 21 (9), 092002.

Y. Shakalisava , M. Poitevin , J. L. Viovy & S. Descroix 2009 Versatile method for electroosmotic flow measurements in microchip electrophoresis. J. Chromatogr. A 1216 (6), 10301033.

T. L. Sounart & J. C. Baygents 2007 Lubrication theory for electro-osmotic flow in a non-uniform electrolyte. J. Fluid Mech. 576, 139172.

G. Taylor 1953 Dispersion of soluble matter in solvent flowing slowly through a tube. Proc. R. Soc. Lond. A 219 (1137), 186203.

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