What is ISO 22125‑1 - LSC for 99Tc in water about?
ISO 22125‑1 is the first part of the ISO 22125 series on water quality. ISO 22125‑1 specifies a method for the measurement of Technetium-99 (99Tc) in all types of waters by liquid scintillation counting (LSC). ISO 22125‑1 provides a method that is applicable to test samples of supply/drinking water, rainwater, surface, and groundwater, as well as cooling water, industrial water, domestic, and industrial wastewater after proper sampling and handling and test sample preparation. Filtration of the test sample is necessary.
The detection limit depends on the sample volume and the instrument used. The method described in ISO 22125‑1 is using currently available LSC instruments that have a detection limit of approximately 5 Bq·kg−1 to 20 Bq·kg−1, which is lower than the WHO criteria for safe consumption of drinking water (100 Bq l−1). These values can be achieved with a counting time of 30 min for a sample volume varying between 14 ml to 40 ml.
Note: The method presented in ISO 22125‑1 is not intended for the determination of an ultra-trace amount of 99Tc.
Who is ISO 22125‑1 - LSC for 99Tc in water for?
ISO 22125‑1 on LSC for 99 Tc in water is useful for:
- Government laboratories / test laboratories
- Industries that release wastewater in natural water bodies
- Geological scientists
- Nuclear power plants
- Public water supply systems
Why should you use ISO 22125‑1- LSC for 99Tc in water?
Radioactivity from several naturally occurring and anthropogenic sources is present throughout the environment. Thus, water bodies (such as surface waters, groundwaters, sea waters) can contain radionuclides of natural, human-made, or both origins. ISO 22125‑1 is one of a set of International Standards on test methods dealing with the measurement of the activity concentration of radionuclides in water samples.
ISO 22125‑1 provides a test method that is adapted so that the character limits, decision threshold, detection limit, and uncertainties ensure that the radionuclide activity concentrations test results can be verified to be below the guidance levels required by a national authority for either planned/existing situations or for an emergency situation. ISO 22125‑1 has been developed to answer the need of test laboratories carrying out these measurements, which are sometimes required by national authorities, as they may have to obtain a specific accreditation to test for radionuclide measurement in drinking water samples.