Electrochemical determination of heavy metals in water and apparatus therefor

US4146436A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Walter Kellermann · Eckental, DE
• Herbert Nischik
• Ferdinand V. Sturm · Erlangen, DE

Key dates

• Filing date: Mar 7, 1978
• Grant date: Mar 27, 1979
• Expiry date: Mar 7, 1998

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/48
• WIPO field: Measurement
• WIPO sector: Instruments

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.