This document specifies the determination of radium-226 (226Ra) activity concentration in non-saline
water samples by extraction of its daughter radon-222 (222Rn) and its measurement using liquid
scintillation analysis.
The test method described in this document, using currently available scintillation counters, has a
detection limit of approximately 50 mBq·l−1. This method is not applicable to the measurement of other
radium isotopes.