NF EN ISO 13162

<p>ISO 13162:2011 specifies the conditions for the determination of ¹⁴C activity concentration in samples of environmental water or of ¹⁴C-containing water using liquid scintillation counting.</p> <p>The method is applicable to the analysis of any organic molecule soluble in water that is well mixed with the scintillation cocktail. It does not apply to micelles or "large" particles (lipids, fulvic acid, humic acid, etc.) that are inadequately mixed with the scintillation cocktail and the water. Some beta energy is lost without any excitation of the scintillation cocktail and the results are underestimated. The method is not applicable to the analysis of organically bound ¹⁴C, whose determination requires additional chemical processing (such as chemical oxidation, combustion).</p> <p>It is possible to determine ¹⁴C activity concentrations below 10⁶ Bq l^-¹ without any sample dilution.</p>

<p>This document specifies a method for the measurement of ¹⁴C activity concentration in all types of water samples by liquid scintillation counting (LSC) either directly on the test sample or following a chemical separation.</p> <p>The 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.</p> <p>The detection limit depends on the sample volume, the instrument used, the sample counting time, the background count rate, the detection efficiency and the chemical recovery. The method described in this document, using currently available liquid scintillation counters and suitable technical conditions, has a detection limit as low as 1 Bq∙l⁻¹, which is lower than the WHO criteria for safe consumption of drinking water (100 Bq·l^-1). ¹⁴C activity concentrations can be measured up to 10⁶ Bq∙l^-1 without any sample dilution.</p> <p>It is the user’s responsibility to ensure the validity of this test method for the water samples tested.</p>