Improved Precision and Accuracy of Quantification of Rare Earth Element Abundances via Medium-Resolution LA-ICP-MS

Abstract

Laser ablation ICP-MS enables streamlined, high-sensitivity measurements of rare earth element (REE) abundances in geological materials. However, many REE isotope mass stations are plagued by isobaric interferences, particularly from diatomic oxides and argides. In this study, we compare REE abundances quantitated from mass spectra collected with low-resolution (m/Δm = 300 at 5% peak height) and medium-resolution (m/Δm = 2500) mass discrimination. A wide array of geological samples was analyzed, including USGS and NIST glasses ranging from mafic to felsic in composition, with NIST 610 employed as the bracketing calibrating reference material. The medium-resolution REE analyses are shown to be significantly more accurate and precise (at the 95% confidence level) than low-resolution analyses, particularly in samples characterized by low (<μg/g levels) REE abundances. A list of preferred mass stations that are least susceptible to isobaric interferences is reported. These findings impact the reliability of REE abundances derived from LA-ICP-MS methods, particularly those relying on mass analyzers that do not offer tuneable mass-resolution and/or collision cell technologies that can reduce oxide and/or argide formation.

Department(s)

Geosciences and Geological and Petroleum Engineering

Comments

Funding for this study was provided through the NASA Science Innovation Fund and Center for Research and Exploration in Space Science and Technology (CRESST).

Keywords and Phrases

Laser ablation; Magnetic sector LA-ICP-MS; Precision; Rare earth elements

International Standard Serial Number (ISSN)

1044-0305; 1879-1123

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2017 Springer Verlag, All rights reserved.

Publication Date

01 Nov 2017

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