The standard applies to all types of water. The detection limit depends on the device used; In general, chromium contents can be determined from 0.02 mg/l. For chromium contents lower than 0.10 mg/l, use of graphite furnace technology is recommended, see NEN 6444.
NEN 6448-1981 history
1981NEN 6448-1981 Water - Determination of chromium content by atomic absorption spectrometry (flame technique)