The standard applies to all types of water. The detection limit depends on the device used; In general, manganese levels can be determined from 0.01 mg/l. For levels lower than 0.05 mg/l, use of graphite oven technology is recommended, see NEN 6466.
NEN 6461-1981 history
1981NEN 6461-1981 Water - Determination of manganese content by atomic absorption spectrometry (flame technique)