scope:

This document specifies methods used to determine Strontium-90 (⁹⁰Sr) by inductively coupled plasma mass spectrometry (ICP-MS). The mass concentrations obtained can be converted into an activity concentration.

The method is applicable to test samples of supply/drinking water, rainwater, surface and ground water, as well as cooling water, industrial water, domestic, and industrial wastewater after proper sampling and handling, and test sample preparation.

The detection limit depends on the sample volume, the instrument used, the background count rate, the detection efficiency, the counting time, and the chemical yield. The detection limit of the method described in this document, using currently available apparatus and chemical pre-concentration, is approximately 5 Bq·l⁻¹, which is lower than the WHO criteria for safe consumption of drinking water (10 Bq·l⁻¹)^[4].

This method covers the measurement of ⁹⁰Sr in water at activity concentrations up to 1 000 Bq·l⁻¹. Samples with higher concentrations than 1 000 Bq·l⁻¹ can be measured if a dilution is performed.

The method described in this document is applicable in the event of an emergency situation.

Filtration of the test sample is necessary. The analysis of ⁹⁰Sr adsorbed to suspended matter is not covered by this method. If suspended material has to be removed or analysed, filtration through a 0,45 μm filter is recommended. The analysis of the insoluble fraction requires a mineralization step that is not covered by this document. In this case, the measurement is made on the different phases obtained.

It is the user's responsibility to ensure the validity of this test method for the water samples tested.