The standard applies to all types of water with the exception of seawater. In the described manner, depending on the quantity used, contents of 2 µg/l As and higher can be determined in drinking and surface water, while in waste water the lower limit is 5 µg/l As. Antimony in concentrations greater than several times the arsenic content interferes with the determination because antimony hydrogen also develops a red color with the reagent. This color shows an absorption maximum at 510 nm.
NEN 6669-1981 history
1981NEN 6669-1981 Water - Photometric determination of arsenic