Andrzej Lewenstam | AGH University of Science and Technology (original) (raw)
Papers by Andrzej Lewenstam
Springer eBooks, 1990
Although there is no doubt that surface science is a discipline on its own, in practically orient... more Although there is no doubt that surface science is a discipline on its own, in practically oriented electroanalytical chemistry it is mostly an auxiliary force to establish the mechanism of electrode signal. A recent, rapid development of electroanalytical sensors provided the evidence that to get more incisive knowledge of surface-located signal forming processes it is necessary to set a new or to improve existing analytical procedures. Therefore the inspection of surface processes by suitable methods seems to be an indispensable feature of electroanalytical chemistry of today.
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Talanta, Sep 1, 1976
The diffusion-layer model for the chalcocite (Cu(2)S) membrane electrode is discussed. It is equi... more The diffusion-layer model for the chalcocite (Cu(2)S) membrane electrode is discussed. It is equivalent to a simpler model based on exchange reactions at the electrode surface. The chalcocite is sensitive to copper(I) and copper(II) ions and the theoretically predicted response is in good agreement with experimental data. The membrane is a conductor, but this does not significantly affect its function as an ion detector. The limitation of the electrode is the membrane solubility as shown when Cu(II) ions in contrast to copper(I) ions are strongly complexed.
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Defect and Diffusion Forum, Mar 1, 2009
Ionic concentrations and electric field space profiles in one dimensional membrane are described ... more Ionic concentrations and electric field space profiles in one dimensional membrane are described using Nernst-Planck-Poisson (NPP) equations. The usual assumptions for the steady state NPP problem requires knowledge of the boundary values of the concentrations and electrical potential difference. In analytical chemistry the potential difference may not be known and its theoretical prediction from the model is desirable. The effective methods of the solution to the NPP equations are presented. The Poisson equation is solved without widely used simplifications such as the constant field or the electroneutrality assumptions. The first method uses a steady state formulation of NPP problem. The original system of ODEs is turned into the system of non-linear algebraic equations with unknowns fluxes of the components and electrical potential difference. The second method uses the time-dependent form of the Nernst-Planck-Poisson equations. Steady-state solution has been obtained by starting from an initial profiles, and letting the numerical system evolve until a stationary solution is reached. The methods have been tested for different electrochemical systems: liquid junction and ion selective electrodes (ISEs). The results for the liquid junction case have been also verified with the approximate solutions leading to a good agreement. Comparison with the experimental results for ISEs has been carried out.
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Fresenius Journal of Analytical Chemistry, 1993
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Analytica Chimica Acta, 1990
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Analytical Proceedings, 1991
... Michael EG Lyons, Cormac H. Lyons, Declan E. McCormack," Thomas J. McCabe an... more ... Michael EG Lyons, Cormac H. Lyons, Declan E. McCormack," Thomas J. McCabe and William Breen* Physical Chemistry Laboratory, University of Dublin, Trinity College, Dublin 2, Ireland John F. Cassidy Chemistry Department, Dublin Institute of Technology, Kevin Street ...
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Analytica Chimica Acta, Feb 1, 1993
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Journal of Electroanalytical Chemistry, Nov 1, 2011
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Journal of Applied Electrochemistry, May 1, 1982
ABSTRACT
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Analytica Chimica Acta, Feb 1, 2000
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Talanta, 1977
On the basis of a diffusion-layer model the selectivity coefficients of solid-state electrodes ha... more On the basis of a diffusion-layer model the selectivity coefficients of solid-state electrodes have been interpreted. In the Nernst equation the concentration of the principal ion may be expressed in terms of the diffusion coefficients D(B), D(C) and the equilibrium constant K of the reaction AB + C right harpoon over left harpoon AC + B where AB represents the membrane material and C the interfering ion, in the form of an equation: [B](0)=KD (B)KD (B) + D (C)[B] + KD (C)KD (B) + D (C)[C] where the concentration with subscript "0" denotes the surface concentration directly influencing the electrode potential, and [B] and [C] are bulk concentrations of the species indicated. The differences between various literature data can be explained on the basis of this model.
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Analytica Chimica Acta, 1990
ABSTRACT Basic observations leading to the successful application of magnesium ion-selective elec... more ABSTRACT Basic observations leading to the successful application of magnesium ion-selective electrodes for the automated determination of ionized magnesium in undiluted serum are discussed. The principles of the method are described and the first numerical results are reported.
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Analytical Chemistry, Oct 1, 2004
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Analyst, 1976
ABSTRACT
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Analytica Chimica Acta, Apr 1, 1996
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Electroanalysis, Nov 19, 2012
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Scandinavian Journal of Clinical & Laboratory Investigation, 1994
Design of ion-selective electrodes (ISEs) currently used in clinical analysis is presented. The t... more Design of ion-selective electrodes (ISEs) currently used in clinical analysis is presented. The theory of these sensors is outlined. Problems specific for the application of ISEs in clinical analysis are discussed.
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Analytica Chimica Acta, Jul 1, 2007
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Electroanalysis, Nov 2, 2016
Properties of membranes based on quaternary ammonium salts as an ion‐exchanger were investigated.... more Properties of membranes based on quaternary ammonium salts as an ion‐exchanger were investigated. The analytical performance of electrodes was studied by potentiometric measurements. All developed electrodes showed a near‐Nernstian response. However, the best analytical properties were observed for the electrode with DOS plasticizer. The influence of sample matrix components was estimated by Plackett‐Burman experimental design. The effect of five different potential interferents – concentration of anions, which usually exist in mineral water – was examined. The proposed potentiometric sensor was successfully applied for the determination of hydrogen carbonate (bicarbonate) in mineral water samples.
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Talanta, Dec 1, 2011
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Springer eBooks, 1990
Although there is no doubt that surface science is a discipline on its own, in practically orient... more Although there is no doubt that surface science is a discipline on its own, in practically oriented electroanalytical chemistry it is mostly an auxiliary force to establish the mechanism of electrode signal. A recent, rapid development of electroanalytical sensors provided the evidence that to get more incisive knowledge of surface-located signal forming processes it is necessary to set a new or to improve existing analytical procedures. Therefore the inspection of surface processes by suitable methods seems to be an indispensable feature of electroanalytical chemistry of today.
Bookmarks Related papers MentionsView impact
Talanta, Sep 1, 1976
The diffusion-layer model for the chalcocite (Cu(2)S) membrane electrode is discussed. It is equi... more The diffusion-layer model for the chalcocite (Cu(2)S) membrane electrode is discussed. It is equivalent to a simpler model based on exchange reactions at the electrode surface. The chalcocite is sensitive to copper(I) and copper(II) ions and the theoretically predicted response is in good agreement with experimental data. The membrane is a conductor, but this does not significantly affect its function as an ion detector. The limitation of the electrode is the membrane solubility as shown when Cu(II) ions in contrast to copper(I) ions are strongly complexed.
Bookmarks Related papers MentionsView impact
Defect and Diffusion Forum, Mar 1, 2009
Ionic concentrations and electric field space profiles in one dimensional membrane are described ... more Ionic concentrations and electric field space profiles in one dimensional membrane are described using Nernst-Planck-Poisson (NPP) equations. The usual assumptions for the steady state NPP problem requires knowledge of the boundary values of the concentrations and electrical potential difference. In analytical chemistry the potential difference may not be known and its theoretical prediction from the model is desirable. The effective methods of the solution to the NPP equations are presented. The Poisson equation is solved without widely used simplifications such as the constant field or the electroneutrality assumptions. The first method uses a steady state formulation of NPP problem. The original system of ODEs is turned into the system of non-linear algebraic equations with unknowns fluxes of the components and electrical potential difference. The second method uses the time-dependent form of the Nernst-Planck-Poisson equations. Steady-state solution has been obtained by starting from an initial profiles, and letting the numerical system evolve until a stationary solution is reached. The methods have been tested for different electrochemical systems: liquid junction and ion selective electrodes (ISEs). The results for the liquid junction case have been also verified with the approximate solutions leading to a good agreement. Comparison with the experimental results for ISEs has been carried out.
Bookmarks Related papers MentionsView impact
Fresenius Journal of Analytical Chemistry, 1993
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Analytica Chimica Acta, 1990
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Analytical Proceedings, 1991
... Michael EG Lyons, Cormac H. Lyons, Declan E. McCormack," Thomas J. McCabe an... more ... Michael EG Lyons, Cormac H. Lyons, Declan E. McCormack," Thomas J. McCabe and William Breen* Physical Chemistry Laboratory, University of Dublin, Trinity College, Dublin 2, Ireland John F. Cassidy Chemistry Department, Dublin Institute of Technology, Kevin Street ...
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Analytica Chimica Acta, Feb 1, 1993
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Journal of Electroanalytical Chemistry, Nov 1, 2011
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Journal of Applied Electrochemistry, May 1, 1982
ABSTRACT
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Analytica Chimica Acta, Feb 1, 2000
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Talanta, 1977
On the basis of a diffusion-layer model the selectivity coefficients of solid-state electrodes ha... more On the basis of a diffusion-layer model the selectivity coefficients of solid-state electrodes have been interpreted. In the Nernst equation the concentration of the principal ion may be expressed in terms of the diffusion coefficients D(B), D(C) and the equilibrium constant K of the reaction AB + C right harpoon over left harpoon AC + B where AB represents the membrane material and C the interfering ion, in the form of an equation: [B](0)=KD (B)KD (B) + D (C)[B] + KD (C)KD (B) + D (C)[C] where the concentration with subscript "0" denotes the surface concentration directly influencing the electrode potential, and [B] and [C] are bulk concentrations of the species indicated. The differences between various literature data can be explained on the basis of this model.
Bookmarks Related papers MentionsView impact
Analytica Chimica Acta, 1990
ABSTRACT Basic observations leading to the successful application of magnesium ion-selective elec... more ABSTRACT Basic observations leading to the successful application of magnesium ion-selective electrodes for the automated determination of ionized magnesium in undiluted serum are discussed. The principles of the method are described and the first numerical results are reported.
Bookmarks Related papers MentionsView impact
Analytical Chemistry, Oct 1, 2004
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Analyst, 1976
ABSTRACT
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Analytica Chimica Acta, Apr 1, 1996
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Electroanalysis, Nov 19, 2012
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Scandinavian Journal of Clinical & Laboratory Investigation, 1994
Design of ion-selective electrodes (ISEs) currently used in clinical analysis is presented. The t... more Design of ion-selective electrodes (ISEs) currently used in clinical analysis is presented. The theory of these sensors is outlined. Problems specific for the application of ISEs in clinical analysis are discussed.
Bookmarks Related papers MentionsView impact
Analytica Chimica Acta, Jul 1, 2007
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Electroanalysis, Nov 2, 2016
Properties of membranes based on quaternary ammonium salts as an ion‐exchanger were investigated.... more Properties of membranes based on quaternary ammonium salts as an ion‐exchanger were investigated. The analytical performance of electrodes was studied by potentiometric measurements. All developed electrodes showed a near‐Nernstian response. However, the best analytical properties were observed for the electrode with DOS plasticizer. The influence of sample matrix components was estimated by Plackett‐Burman experimental design. The effect of five different potential interferents – concentration of anions, which usually exist in mineral water – was examined. The proposed potentiometric sensor was successfully applied for the determination of hydrogen carbonate (bicarbonate) in mineral water samples.
Bookmarks Related papers MentionsView impact
Talanta, Dec 1, 2011
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