The working principle of UREA Analyzer is based on a chromatographic separation, namely LC-OND (Liquid Chromatography – Organic Nitrogen Detection).
The mobile phase (salt buffer) is pre-cleaned by a specially designed oxidation reactor. A defined volume of aqueous sample is picked up by a loop and injected into the continuous stream of the mobile phase. The sample is then fed to a pump and a chromatographic column where urea is separated from other N-species, like nitrate and ammonium.
After leaving the chromatographic column, the solution is fed to a short-wave UV-oxidation lamp reactor where urea is converted to nitrate.
Nitrate is then selectively detected by a low-wave UV absorption detector (UVD).
All species elute according to their specific retention times. Retention time is used for identification, while peak area units are used for quantification.