The standard applies to all types of water with cyanide levels from 1 /ig/l, expressed as cyanide ions. Some volatile organic compounds, including formaldehyde, may interfere with the determination. The interference caused by sulfides can be eliminated by adding a cadmium salt.
NEN 6489-1982 history
1982NEN 6489-1982 Water - Photometric determination of total cyanide content