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: The invention relates to an implantable dosing device for the continuous, controllable release of medication in the human or animal body, comprising a medicine reservoir of variable volume and a liquid chamber which is tensionally connected to the medicine reservoir and the volume of which can be varied by liquid which is transported through an ion exchange diaphragm by electro-osmosis due to an electric field between two electrodes. According to the invention, the electrodes in such an implantable dosing device are hydrogen electrodes which are connected to each other by a line for hydrogen, and means are further provided for compensating hydrogen losses.