The standard applies to all types of water. Starting from a 40 ml analysis sample and using cuvettes with a light path of 40 mm, a lower analysis limit of p{N) — 0.01 mg/l is achievable. Notes 1. Some amines are also determined as ammonium, even after dis illation. 2. Dis illation is necessary if the sample for analysis is strongly colored and/or cloudy, or if cloudiness occurs during color development.
NEN 6472-1983 history
1983NEN 6472-1983 Water - Photometric determination of ammonium content