Patent ID: 8236567
Filing Date: 2012-08-07
Classification: G01N

Abstract:
1. A method for the automated determining of the chemical oxygen demand of a liquid sample, comprising the steps: mixing the liquid sample with sulfuric acid; introducing a carrier gas, especially air, into the liquid sample-sulfuric acid mixture and extracting the carrier gas from the liquid sample-sulfuric acid mixture; adding an oxidizing agent to the liquid sample-sulfuric acid mixture to form a reaction mixture; heating the reaction mixture at the boiling temperature of the reaction mixture for a predetermined time period; photometrically determining consumption of said oxidizing agent in the reaction mixture including: irradiating the reaction mixture with light of a light source passing along a measuring path through the reaction mixture to a light receiver; ascertaining from the corresponding light receiver signal an absorbance of the reaction mixture; and ascertaining therefrom the consumption of said oxidizing agent in the reaction mixture; and ascertaining the chemical oxygen demand of the liquid sample from the determined consumption of said oxidizing agent in the reaction mixture, wherein: all steps are automatedly performed in an analytical system with the assistance of an evaluating and control unit.