A new rapid protocol for $^{226}$Ra separation and preconcentration in natural water samples using molecular recognition technology for ICP-MS analysis

Marine Verlinde (1) , J. Gorny (1) , Gilles F Montavon (2) , S. Khalfallah (2) , B. Boulet (3) , C. Augeray (4) , D. Lariviere (5) , C. Dalencourt , Alkiviadis Gourgiotis (1)

1 IRSN/PSE-ENV/SEDRE/LELI - Laboratoire de recherche sur le devenir des pollutions de sites radioactifs
2 SUBATECH - Laboratoire de physique subatomique et des technologies associées
3 IRSN/PSE-ENV/SAME/LMRE - Laboratoire de métrologie de la radioactivité dans l'environnement
4 IRSN/PSE-ENV/SAME/LERCA - Laboratoire d'expertise, de radiochimie et de chimie analytique
5 TPCIM - Département Technologie des Polymères et Composites & Ingénierie Mécanique

A new rapid protocol for 226Ra separation and preconcentration in natural water samples was developed before its determination by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). For this purpose, the commercially available Ra specific resin AnaLig® Ra-01 was used. This resin shows a high selectivity for radium in a large range of acid concentrations and no affinity or possible elution of 226Ra interfering elements. The distribution coefficients of Ra and other elements over a wide range of acid (HCl and HNO3) concentrations were obtained. Due to the high radium selectivity, the new developed protocol uses only 50 mg of dry resin and its performance was evaluated using 100 mL of three natural waters with different ionic strengths, spiked with a known quantity of 226Ra. Radium was successfully separated and preconcentrated-yielding recoveries ranging between 72% and 86%. In parallel with the characterisation of the resin sorption properties, a detailed study of polyatomic interferences was carried out in our ICP-MS allowing to identify the prominent elements favouring interferences at m/z = 226. Furthermore, a 226Ra sensitivity comparison between different ICP-MS instruments and configurations was done in order to determine high sensitivity conditions for radium analysis.

Domaines: Radiochimie; Sciences de l'environnement

Marine Verlinde, J. Gorny, Gilles F Montavon, S. Khalfallah, B. Boulet, et al.. A new rapid protocol for $^{226}$Ra separation and preconcentration in natural water samples using molecular recognition technology for ICP-MS analysis. Journal of Environmental Radioactivity, 2019, 202, pp.1-7. ⟨10.1016/j.jenvrad.2019.02.003⟩. ⟨hal-02391116⟩