Authors: Dirk Arnold, Rasmus Andreasen, Oktay Cankur, Lucille Chambon, Marcus Christl, José Antonio Corcho Alvarado, Stefan Röllin f, Betül Ari Engin, Arunas Gudelis, Karin Hain, Violeta Hansen, Steffen Happel, Mihail-Razvan Ioan, Johanna Irrgeher, Simon Jerome, Béatrice Lalère, Valérie Lourenço, Dmitriy Malinovskiy, Monika Mazánová, Jelena Krneta Nikolić, Tea Zuliani
Abstract:
The European Green Deal's ambition for zero pollution requires development of highly sensitive techniques to detect ultra-low amounts of pollutants and isotope ratios, where mass spectrometry is a key method. The MetroPOEM project bridges the traceability gap between activity and mass-based measurements.
Low level radioactive standard solutions (90Sr, 237Np, 234U, 236U, natural uranium (Unat), 239Pu, 240Pu, 241Am, 239,240Pu) were distributed to 18 partner laboratories for measurement by mass spectrometric and decay counting techniques. The results and data analysis will be published separately.
SI-traceable high precision methods were developed for isotope ratio determination of Li, B, Cr, Cd, Ni, Sb, Pb and U in seawater. Method development addressed analyte separation from the matrix, evaluation of calibration approaches, isotope fractionation corrections and uncertainty estimation.
Seawater (250 L) was taken from the German North Sea exclusive economic zone (DE-EEZ) to develop two certified reference materials (CRMs). Part of this material was used to generate a CRM with SI traceability for isotope ratios of Li, B, Cr, Cd, Ni, Sb, Pb and U. The second part was used to generate a seawater CRM, spiked with Unat, 237Np, 239,240Pu and 241Am.
A solid silica-based CRM, spiked with Unat, 237Np, 239,240Pu and 241Am, was produced by sol-gel synthesis, with ∼10 kg of inactive material for method development.
These materials were characterised in accordance with ISO 17034 by interlaboratory studies between project partners, using techniques developed in the project.
Two Good Practice Guides, on (i) measurement of radioactivity by mass spectrometry, and (ii) sample treatment, uncertainties, and mass bias quantification, are in draft.
