Measurement uncertainty arising from sampling of environmental samples

Denis Glavič-Cindro; Eyakifama Hazou; Matjaž Korun; Romana Krištof; Petra Osterman; Toni Petrovič; Branko Vodenik; Benjamin Zorko

doi:10.1016/j.apradiso.2019.108978

Measurement uncertainty arising from sampling of environmental samples

Appl Radiat Isot. 2020 Feb:156:108978. doi: 10.1016/j.apradiso.2019.108978. Epub 2019 Nov 9.

Authors

Denis Glavič-Cindro¹, Eyakifama Hazou², Matjaž Korun³, Romana Krištof⁴, Petra Osterman³, Toni Petrovič³, Branko Vodenik³, Benjamin Zorko³

Affiliations

¹ Jožef Stefan Institute, Jamova cesta 39, SI-1000, Ljubljana, Slovenia. Electronic address: denis.cindro@ijs.si.
² University of Lome, P.O. Box: 1515, Lome, Togo.
³ Jožef Stefan Institute, Jamova cesta 39, SI-1000, Ljubljana, Slovenia.
⁴ Faculty of Health Sciences, Zdravstvena pot 5, Ljubljana, Slovenia.

PMID: 31770713
DOI: 10.1016/j.apradiso.2019.108978

Abstract

In 2017, a new revision of the ISO/IEC 17025 standard was issued. One of the important changes is that the uncertainty arising from sampling has to be evaluated. Based on this new requirement, we evaluated the contribution of the sampling procedure to the total uncertainty budget of the high-resolution gamma-ray spectrometry of environmental soil, tap water and aerosol filter samples. We performed statistical analyses of measurements of sets of samples taken from the same target in the same general time period. The determination of sampling uncertainty was based on the evaluation of the standard deviation of the set of measurement results and the combined uncertainty budget of sample preparation and analysis. When the spatial and temporal heterogeneities are low, the sampling uncertainty is estimated to be around 5% (k = 1) for soil samples and 30-40% (k = 1) for air samples. For single tap water samples collected consecutively, sampling uncertainty does not have a significant contribution to the complete uncertainty budget.

Keywords: Environmental samples; High resolution gamma-ray spectrometry; ISO/IEC 17025:2017; Radioactivity; Radionuclides; Sampling; Sampling uncertainty; Uncertainty; Uncertainty budget.