Voltammetry of metal complex systems with different diffusion coefficients of the species involved

Anodic Stripping Voltammetry of Metal Ions in Mixtures of Ligands

“…Under such conditions, the model has a solution analogous to that for the case of labile complexation in the approach by de Jong et al [2][3][4]. Indeed, the Cottrell-like expression for the peak or limiting current I lim is formally identical…”

“…If such limiting current was totally controlled by diffusion, it would be proportional to the mean diffusion coefficient of the system to the power 1/2, as stated by the 'polarographic' model by de Jong et al [2][3][4]. In contrast, if the hydrodynamic conditions are controlled by laminar convection in a similar way as in the RDE, the peak current should be proportional to the mean diffusion coefficient to the power 2/3, by analogy to the Levich's equation [16].…”

“…Moreover, in recent years, the study of metal complexation by macromolecular ligands has received especial attention due to the great importance of such ligands in environmental analysis. Among the different partial approaches to the general case, the voltammetric model of de Jong, van Leeuwen and Holub [2][3][4] appears to be especially useful, although it is restricted to the case of a unique metal ion-macromolecule complex in the absence of electrodic adsorption. In the limiting case of labile complexation, the model has been applied successfully to different metal ion-macromolecule systems (synthetic macromolecules, humic and fulvic acids, polysaccharides, etc.)…”

Target transform fitting in a voltammetric study of metal complexation

“…It seems that a suitable hard-model chemometric method can be used for analyzing data matrices obtained from this type of complexation systems. Although hardmodel methods in different manners including modelization of chemical equilibrium only [7] or modelization of both chemical equilibrium and electrochemical processes [9][10][11][12] have been used in such systems, to the best of our knowledge this is the first time that target transform fitting (TTF) is used as a hard-model method to data analysis in electrochemistry. Application of TTF in this work consists of modelling both chemical equilibria and electrochemical process.…”

Solution Equilibria. A Unified Mathematical Treatment of Potentiometric and Polarographic Data in a Metal-Ligand Equilibrium Study at a Fixed Ligand to Metal Ratio and Various pH Values

“…Not surprisingly, there is not a general theory to date that would allow one to study any kind of metal complexes by voltammetry. Instead, several techniques were proposed that were focused either on fully labile [2][3][4], nonlabile [5][6], or inert [7][8][9] metal-ligand systems, simple inorganic ligands [10,11] or polyelectrolytes [7][8][9][12][13][14] etc. All these techniques were developed for the experimental conditions where experiment was performed at fixed pH and in the presence of an access of a ligand.…”