Abstract: A method for electrochemically determining the concentration of heavy metals in water by precipitating the metals at a solid electrode under the influence of a constant negative d-c voltage and subsequently dissolving them by anodic oxidation, in which the metals are precipitated at a platinum metal electrode; the water is then replaced by an electrolytic solution and the precipitated metals are dissolved again by suddenly changing the negative d-c voltage into a constant positive d-c voltage, while the electric charge required for the dissolution is determined and the concentration is determined therefrom; the time of application and the magnitude of the d-c voltage are always kept constant during the precipitation as well as during the dissolution of the metals.

Abstract: A method for determining the concentration of carbon monoxide in the air along with a measuring electrode for carrying out the method in which the degree of inhibition of an electrochemical reaction caused by the carbon monoxide, in particular the inhibition of a cathodic oxygen reduction, is determined. Preferably the measurement is made with the electric potential held constant and the change in current taking place during inhibition used as a measure of concentration.