ISO 13168:2015 describes a test method for the simultaneous measurement of tritium and carbon-14 in water samples by liquid scintillation counting of a source obtained by mixing the water sample with a hydrophilic scintillation cocktail.
This is considered a screening method because of the potential presence of interfering nuclides in the test sample.
The method can be used for any type of environmental study or monitoring.
ISO 13168:2015 is applicable to all types of waters having an activity concentration ranging from 5 Bq/l to 106 Bq/l (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.