ISO 13166:2014 specifies the conditions for the determination of uranium isotope activity concentration in samples of environmental water (including sea waters) using alpha-spectrometry and ²³²U as a yield tracer. A chemical separation is required to separate and purify uranium from a test portion of the sample.

Plutonium isotopes can interfere, if present, with detectable activities in the sample.

The detection limit for measurement of a test portion of about 500 ml is approximately 5 mBq · l⁻¹ with a counting time of about 200 000 s.