Resolving Severe Elemental Isobaric Interferences with a Combined Atomic and Molecular Ionization Source–Orbitrap Mass Spectrometry Approach: The 87Sr and 87Rb Geochronology Pair

Autor:	Edward D. Hoegg, R. Kenneth Marcus, Ryszard Lobinski, Joanna Szpunar, David W. Koppenaal, Simon Godin
Rok vydání:	2021
Předmět:	Accuracy and precision Isotope law Chemistry Ionization Geochronology Analytical chemistry Isobaric process Degree of certainty Mass spectrometry Orbitrap Analytical Chemistry law.invention
Zdroj:	Analytical Chemistry. 93:11506-11514
ISSN:	1520-6882 0003-2700
Popis:	Many fields of basic and applied sciences, including geochronology, astronomy, metabolism, etc., rely on the ability of mass spectrometry to obtain isotope ratio measurements having a high degree of certainty. The inability to resolve difficult isobaric interferences plagues certain measurements. A combined atomic and molecular (CAM) ionization source has been interfaced to a high-field Orbitrap mass spectrometer to alleviate severe atomic, isobaric interferences. This work examines the geochronologically significant 87Sr and 87Rb isotope pair. The mass difference between 87Sr and 87Rb is approximately 0.3 mDa, requiring a minimum resolving power (R = m/Δm) of ∼290,000, a value ∼30× higher than available with sector-field elemental mass spectrometers. Under ultrahigh-resolution conditions, Sr isotope ratio accuracy and precision were evaluated using NIST Sr SRM 987, yielding precision values of 1.7M. At equal 87Sr and 87Rb intensities, 87Sr/86Sr was measured as 0.71294 (a relative error of only 0.37%) with a precision of 0.097% RSD, clearly reflecting the alleviation of the isobaric interference.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7cbd4a8bcb44a42c918e9e9fb6732719 https://doi.org/10.1021/acs.analchem.1c01795 Zobrazit plný text záznamu