Voltammetry of heterogeneous labile metal-macromolecular systems for any ligand-to-metal ratio.: Part III. Rigorous computation of the binding curve from the normalised limiting currents

A self consistent procedure which uses the limiting currents of a titration experiment for the rigorous computation of the binding curve of the labile complexes formed with a metal and a heterogeneous ligand is presented. The homogeneous complexation model corresponding to the mean stability constant of all the affinity spectra is used as a first trial complexation model to compute the fractions of bound or free metal in bulk conditions along the titration. Afterwards, the binding curve so obtained is used in an iterative procedure to improve the computation of the fraction of free metal in bulk conditions at each metal-to-ligand ratio up to convergence. The resulting numerical process constitutes a rigorous way to obtain the binding curve. Its application to some cases with discrete or continuous affinity spectra is presented.