Stripping voltammetric detection in high-precision titrimetry

Anodic stripping voltammetry is used to detect the equivalence point in compleximetric titration. The sensitivity of detection thus provided enables the attainable precision to be markedly improved. Theoretical treatment of the electrochemical deposition of a metal from media containing a complexing agent such as EDTA in large excess is based on the model of reversible reduction of the complex formed, as worst case. It is shown that anodic stripping voltammetry can be applied if the conditional stability constant of the complex is appropriate. Semi-automatic techniques are outlined for improving the speed and ease of operation. Indium, cadmium, and bismuth can be titrated with EDTA, with a relative standard deviation of less than 0.01%.