Method for monitoring concentration of water borne substance in an aqueous medium

A method for monitoring the concentration of a water borne substance in an aqueous medium, comprising the steps of:

• introducing a defined amount of the aqueous medium into a gas circulatory system of an analytical apparatus comprising a high temperature reaction chamber and a measuring chamber comprises, wherein the gas circulatory system extends through the high temperature reaction chamber and the measuring chamber, and wherein the introducing of the aqueous medium occurs upstream of the high temperature reaction chamber or into it;
• evaporating the aqueous medium in the high temperature reaction chamber;
• reacting the water borne substance with at least one reaction partner in the high temperature reaction chamber to a gaseous reaction product;
• registering the current value of a measured variable, which is a function of the concentration of the chemical species of the reaction product in the gas circulatory system, wherein the concentration of the chemical species of the reaction product in the gas circulatory system depends, on the one hand, on a time-dependent state of the gas circulatory system and, on the other hand, on the concentration of the substance in the aqueous medium;
• and
• ascertaining the concentration of the substance in the aqueous medium by applying the current value of the measured variable, wherein:
• in the ascertaining of the concentration of the substance in the aqueous medium, the contribution to the concentration of the chemical species of the reaction product in the gas circulatory system by the state of the gas circulatory system is ascertained on the basis of a model of the state, and a correction of the concentration of the chemical species of the reaction product in the gas circulatory system occurs on the basis of this contribution.