The liquid junction potential

This work is aimed to give an electrochemical insight into the ionic transport phenomena in the cellular environment of organized brain tissue. The Nernst–Planck–Poisson (NPP) model is presented, and its applications in the description of electrodiffusion phenomena relevant in nanoscale neurophysiology are reviewed. These phenomena include: the signal propagation in neurons, the liquid junction potential in extracellular space, electrochemical transport in ion channels, the electrical potential distortions invisible to patch-clamp technique, and calcium transport through mitochondrial membrane. The limitations, as well as the extensions of the NPP model that allow us to overcome these limitations, are also discussed.

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Liquid Junction Potential in Potentiometric Titrations. 5. Deduction of the Potential Functions for E.M.F. Cells with Complex Formation and with Liquid Junctions of the Type AY|AY+ BYz(B) + HY + AyL.

Acta Chemica Scandinavica ◽

10.3891/acta.chem.scand.53-0314 ◽

1999 ◽

Vol 53 ◽

pp. 314-319 ◽

Cited By ~ 7

Author(s):

Erzsébet Néher-Neumann ◽

G. Voyiatzis ◽

T. Østvold ◽

Tapani A. Pakkanen ◽

Markku Ahlgrén ◽

...

Keyword(s):

Complex Formation ◽

Potential Functions ◽

Liquid Junction Potential ◽

Liquid Junction ◽

Potentiometric Titrations ◽

Junction Potential

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An Improved Equation for the Liquid Junction Potential at the Interface of Different Solvents

Australian Journal of Chemistry ◽

10.1071/ch9921633 ◽

1992 ◽

Vol 45 (10) ◽

pp. 1633 ◽

Cited By ~ 2

Author(s):

A Berne ◽

C Kahanda ◽

O Popovych

Keyword(s):

Mixed Solvent ◽

Electrolyte Solutions ◽

Transport Numbers ◽

Liquid Junction Potential ◽

Aqueous Methanol ◽

Liquid Junction ◽

Chemical Potentials ◽

Solvent Dependence ◽

New Equation ◽

Junction Potential

The component of the liquid-junction potential due to the diffusion of ions across an interface of electrolyte solutions in different solvents was formulated by taking into account the solvent dependence of the transport numbers, t, and of the chemical potentials of ions in the interphase region as determined from experimental data on their variation in the mixed-solvent compositions. The new equation was applied to NaCl/NaCl and HCl/HCl junctions between water and methanol-water solvents over the entire solvent range. Significant differences between the results obtained with the new equation and the old formulation, which treated the transport numbers as solvent-independent, were observed only for the HCl junctions involving 90-100 wt % aqueous methanol, where tH exhibits a sharp minimum as a function of the solvent composition.

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Ion-selective electrodes for sodium and potassium: a new problem of what is measured and what should be reported.

Clinical Chemistry ◽

10.1093/clinchem/31.3.482 ◽

1985 ◽

Vol 31 (3) ◽

pp. 482-485 ◽

Cited By ~ 58

Author(s):

A H Maas ◽

O Siggaard-Andersen ◽

H F Weisberg ◽

W G Zijlstra

Keyword(s):

Activity Coefficient ◽

Theoretical Calculations ◽

Pair Formation ◽

Ion Selective Electrodes ◽

Residual Liquid ◽

Liquid Junction Potential ◽

Liquid Junction ◽

Normal Plasma ◽

Sodium And Potassium ◽

Junction Potential

Abstract For clinical purposes the activities of Na+ and K+ obtained with ion-selective electrodes in undiluted whole blood or serum should be multiplied by an appropriate factor to obtain the same values as the substance concentrations obtained by flame photometry. The factor is primarily dependent on the mass concentration of water in normal plasma divided by the molal activity coefficient of Na+ (or K+) of normal plasma. We discuss the value of the molal activity coefficient of Na+ obtained by theoretical calculations and by direct measurement. The discrepancies between theory and measurement (gamma Na+ of 0.747 and 0.73, respectively) may be due to some binding of Na+ (protein binding or ion pair formation), a small and variable residual liquid-junction potential, or certainty about the appropriate value for the ionic strength of normal plasma (0.16 mol/kg or somewhat higher).

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