Full Description ADOPTED_FROM:EN ISO 22908:2020 This document specifies the determination of radium-226 (226Ra) and radium-228 (228Ra) activity concentrations in drinking water samples by chemical separation of radium and its measurement using liquid scintillation counting. Massic activity concentrations of 226Ra and 228Ra which can be measured by this test method utilizing currently available liquid scintillation counters go down to 0,01 Bq/kg for 226Ra and 0,06 Bq/kg for 228Ra for a 0,5 kg sample mass and a 1 h counting time in a low background liquid scintillation counter[8]. The test method can be used for the fast detection of contamination of drinking water by radium in emergency situations.