Simulation and fitting of anodic stripping voltammetry data for determination of the metal complexing capacity

The determination of the metal complexing capacity (MCC) was done by anodic stripping voltammetry for 1: 1 complex formations in the presence of one, two or three different ligands. Simulation and fitting were performed after addition of noise and application of the linearization of the Ružić-Van den Berg equation. The evaluation of the results of fitting led to the criteria that must be fulfilled in order to ascertain a simulated model with sufficient accuracy. Taking into account the state-of-the-art of the available measuring systems, the product of the ligand concentration and the stability constant with the metal should be larger than 1, in order to recognize its existence; if there are two ligands, their stability constant ratio should be at least 10, for their accurate distinction. Generally, it appears that 1. (i) MCC can be determined with higher accuracy than stability constants, that 2. (ii) in the case of more ligands, the total MCC can be well determined, while partitioning among them as well as the values for the stability constants were less accurate, and 3. (iii) that not more than two different groups of ligands can be used in the evaluation of one set of experimental data points.