Substituting Chromium – Thermometric Titration Method to Streamline Monitoring of Anodizing Baths
Replacing chromium by less hazardous substitutes such as sulfuric and tartaric acid helps reduce the environmental impact of anodizing metal substrates for corrosion protection. Potentiometric titration is the standard method used to monitor the levels of these acids. This method, however, requires two titrations to be performed with different electrodes and requiring different solvents.
Thermometric titration, on the other hand, allows monitoring sulfuric and tartaric acid using the same sensor in the same matrix. This sensor, a highly sensitive, fast responding thermometer, determines the endpoint of the reaction when no change in the temperature of the sample solution (reaction enthalpy) is registered any more.