Method and apparatus for automated determining of chemical oxygen demand of a liquid sample

US8236567B2 · kind B2 · utility

Assignee

• Endress+Hauser Conducta Gesellschaft fuer Mess- und Regeltechnik mbH + Co. KG · DE

Inventors

• Ulrich Kathe · Leonberg, DE
• Kristoff Kley · Stuttgart, DE
• Thomas Schipolowski · Stuttgart, DE
• Lydia Hoppe · Ditzingen, DE

Key dates

• Filing date: Jul 23, 2010
• Grant date: Aug 7, 2012
• Expiry date: Jul 23, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N33/1806
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and apparatus for automated determining of the chemical oxygen demand of a liquid sample, comprising steps as follows: mixing the liquid sample with sulfuric acid; introducing a carrier gas, especially air, into the liquid sample-sulfuric acid mixture; adding an oxidizing agent to the liquid sample-sulfuric acid mixture to form a reaction mixture; heating (especially under reflux conditions) the reaction mixture at the boiling temperature of the reaction mixture for a predetermined time period; photometrically determining consumption of an oxidizing agent in the reaction mixture; and ascertaining therefrom the chemical oxygen demand of the liquid sample, wherein all steps are automatedly performed in an analytical system with the assistance of an evaluating and control unit.