Application of multivariate curve resolution to the voltammetric data Factor analysis ambiguities in the study of weak consecutive complexation of metal ion with ligand

Interactions between copper and organic macromolecules: determination of conditional complexation constants

“…In recent studies on the complexation of copper with organic molecules, experimental designs appear to be largely used (e.g. [11,12]). The first step was to identify all the parameters which were likely to have an influence on the response Cu*(copper in the filtrate).…”

Voltammetric Soft Modelling Approach for Systems with Both Electrochemically Labile and Inert Complexes: the Zn-Glycine Case

“…Factor analysis (soft modelling) enable the identification of a model from the data set instead of fitting an a priori assumed model [12][13][14][15][16][17][18]. The different steps of the application of this approach in the present work are shown in the flowchart of Figure 1.…”

“…This is due to the fact that the majority of soft modelling approaches assume a linear contribution of each species to the measured signal, which is not always true in electroanalytical data. Although this intrinsic limitation, the applicability of some soft modelling approaches to these data has been shown satisfactory, as the results obtained by our research group can demonstrate [12][13][14][15][16][17][18], and it appears to be an indispensable tool in the cases where hard modelling techniques are not applicable [13,14,16]. Those previous works have shown that in cases of inert complexation where the contribution of each species to the measured signal is linear, the applicability of soft modelling is strictly correct [13][14][15].…”

“…Those previous works have shown that in cases of inert complexation where the contribution of each species to the measured signal is linear, the applicability of soft modelling is strictly correct [13][14][15]. However, when those soft modelling techniques have been applied to systems with purely labile complexation [12,17,18], still quite good results have been obtained although hypothesis of linearity is in this case not totally fulfilled. It must be taken into account that, from an electroanalytical point of view, inert complexes are those which practically do not dissociate within the time-scale of the voltammetric measurement, and labile complexes are those whose associationdissociation kinetics are much faster than the voltammetric measurement.…”

“…It must be taken into account that, from an electroanalytical point of view, inert complexes are those which practically do not dissociate within the time-scale of the voltammetric measurement, and labile complexes are those whose associationdissociation kinetics are much faster than the voltammetric measurement. The formation of 1:1 (metal:ligand) [12] and successive 1:n [17,18] purely labile complexes has been considered in previous works. Complexation of Cd and Pb by glycine [18] has been recently investigated using the here described soft modelling multivariate curve resolution approach and using the classical hard modelling DeFord-Hume method [19].…”