DIN EN ISO 13161:2016-01

This International Standard describes a method for determining the activity concentration of polonium-210 in natural waters using alpha spectrometry. Polonium-210 is a naturally occurring alpha-emitting radionuclide with a half-life of 138 days. It occurs in the natural decay chain of uranium-238. It is a long-lived decay product of radon-222 through lead-210. This International Standard specifies a method for determining the activity concentration of polonium-210 by alpha spectrometry in all types of naturally occurring water. The detection limit of this method depends on the volume of the sample, the counting time, the background count rate and the detection efficiency. In the case of drinking water, the analysis is usually carried out on the raw sample, without filtration or other pretreatment. If suspended material has to be removed or analysed, filtration at 0,45 µm is recommended. The analysis of the insoluble fraction requires a mineralization step that is not covered in this International Standard (see NF M 60-790-4). In this case, the measurement is made on the different phases obtained. The final activity is the sum of all the measured activity concentrations. The text of ISO 13161:2011 has been prepared by Technical Committee ISO/TC 147 "Water quality" of the International Organization for Standardization (ISO) and adopted as EN ISO 13161:2015 by Technical Committee CEN/TC 147 "Water quality", the secretariat of which is held by DIN. The responsible German committee is Working Committee NA 119-01-03 AA "Wasseruntersuchung" ("Water examination") at DIN Standards Committee Water Practice (NAW).