ISO 13168:2023

This document specifies a method for the simultaneous measurement of 3H and 14C in water samples by liquid scintillation counting of a source obtained by mixing the water sample with a hydrophilic scintillation cocktail.
The method presented in this document is considered a screening method because of the potential presence of interfering radionuclides in the test sample. However, if the sample is known to be free of interfering radionuclides then 3H and 14C can be measured quantitatively.
The method can be used for any type of environmental study or monitoring.
This method is applicable to test samples of supply/drinking water, rainwater, surface and ground water, marine water, as well as cooling water, industrial water, domestic, and industrial wastewater having an activity concentration ranging from 5 Bq∙l-1 to 106 Bq∙l-1 (upper limit of the liquid scintillation counters for direct counting). For higher activity concentrations, the sample can be diluted to obtain a test sample within this range.