Measurement of 87 Sr/ 86 Sr in limestones after acid leaching and direct injection in a liquid chromatograph coupled to a multicollector ICP-MS

B. Puente-Berdasco (1) , J. Rodríguez (2) , D. Ballesteros (3, 4) , A. Painchault (5) , C. Nehme (3) , D. Mouralis (3) , J. Gil-Ibarguchi (2) , A. Martín-Izard (1) , J. Garcia Alonso (1)

1 Universidad de Oviedo [Oviedo]
2 UPV / EHU - University of the Basque Country = Euskal Herriko Unibertsitatea
3 IDEES - Identité et Différenciation de l’Espace, de l’Environnement et des Sociétés
4 UGR - Universidad de Granada = University of Granada
5 GRHis - Groupe de Recherche d'Histoire

A procedure for the measurement of 87Sr/86Sr in carbonates without off-line strontium separation was developed, validated and applied to Normandy chalkstones. The method is based on the injection of the dissolved/leached sample into a high-performance liquid chromatography (HPLC) system directly coupled to a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). Matrix and spectral (Ca, Rb) interferences were removed by an on-line separation procedure based on cation exchange chromatography using 1 M nitric acid as an eluent in the presence of 3.8 mM 18-crown-6. The main polyatomic interferent was identified as NO2Ca+, affecting mass 86 of strontium. Isotope ratios were calculated by multiple linear regression from the measured chromatographic peaks. The method was evaluated using a NIST 987 Sr isotope reference material and subsequently validated employing a JCp-1 coral reference material in comparison with the traditional off-line separation procedure. Finally, the method was applied to ten Normandy limestones (chalkstones) with results in agreement with the expected values based on geological, geochemical, and stratigraphic studies

Domaines: Géographie; Chimie

B. Puente-Berdasco, J. Rodríguez, D. Ballesteros, A. Painchault, C. Nehme, et al.. Measurement of 87 Sr/ 86 Sr in limestones after acid leaching and direct injection in a liquid chromatograph coupled to a multicollector ICP-MS. Journal of Analytical Atomic Spectrometry, 2022, 37 (1), pp.194-202. ⟨10.1039/D1JA00340B⟩. ⟨halshs-03513240⟩