ISO 4722-1:2023

This document specifies the method and the conditions for the determination of 232Th activity concentration in samples of environmental water (including sea waters) and waste waters before release to the environment using alpha spectrometry and 229Th as a recovery tracer. A chemical separation allows to separate and purify thorium from a test portion of the sample.
The general principles outlined in this document can be applied for the analysis of other alpha-emitting thorium isotopes such as 228Th and 230Th in aqueous samples.