The method applies to all types of water. Aromatic and heterocyclic nitrogen compounds are not fully determined. Inorganic nitrate and nitrite as well as some metals can interfere with the determination (see 7.4). Assuming a 500 ml analysis sample and a photometric determination after destruction and dis illation, a lower analysis limit of p(N) = 0.1 mg/l is feasible.
NEN 6481-1983 history
1983NEN 6481-1983 Water - Determination of the sum of ammoniacal and organically bound nitrogen according to Kjeldahl after mineralization with selenium