Texas Christian University, Fort Worth, TX, 76129, USA.
NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA.
J Am Soc Mass Spectrom. 2017 Nov;28(11):2344-2351. doi: 10.1007/s13361-017-1745-5. Epub 2017 Jul 10.
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. Graphical Abstract ᅟ.
激光烧蚀电感耦合等离子体质谱（LA-ICP-MS）能够简化和提高地质材料中稀土元素（REE）丰度的高灵敏度测量。然而，许多 REE 同位素质量通道受到同量异位素干扰的困扰，特别是双原子氧化物和氩化物。在这项研究中，我们比较了使用低分辨率（5%峰高处的 m/Δm = 300）和中分辨率（m/Δm = 2500）质量分辨收集的质谱中定量的 REE 丰度。分析了广泛的地质样品，包括从基性到酸性组成的 USGS 和 NIST 玻璃，其中 NIST 610 用作内标校准参考物质。结果表明，中分辨率 REE 分析的准确性和精密度（在 95%置信水平下）明显优于低分辨率分析，特别是在 REE 丰度较低（μg/g 水平以下）的样品中。报告了受同量异位素干扰最小的首选质量通道列表。这些发现影响了从 LA-ICP-MS 方法得出的 REE 丰度的可靠性，特别是那些依赖于不提供可调谐质量分辨率和/或碰撞池技术的质量分析仪的方法，这些技术可以减少氧化物和/或氩化物的形成。图摘要 ᅟ。
