TKN determination in water and waste water using potentiometric titration

An easy, reliable and high troughpout method for the determination of Total Kjeldahl Nitrogen (TKN) in water and waste water, according to ISO 5663, DIN EN 25 663 and the methods listed in 40 CFR part 136.3, is presented. In this study, the Limit of Detection and Limit of Quantification, which are a benchmark for the method’s sensitivity, were determined for water samples. To test the system’s performance, the nitrogen recovery of different concentrations of a urea reference sample was tested.  The samples were digested mercury and selenium free using the KjelDigester K-449. The distillation and potentiometric boric acid titration were performed with the KjelMaster K-375 with KjelSampler K-376.