Improving Precision and Accuracy of Isotope Ratios from Short Transient Laser Ablation-Multicollector-Inductively Coupled Plasma Mass Spectrometry Signals: Application to Micrometer-Size Uranium Particles

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• 作者：Fanny Claverie ; Amélie Hubert ; Sylvain Berail ; Ariane Donard ; Fabien Pointurier ; Christophe Pécheyran
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：April 19, 2016
• 年：2016
• 卷：88
• 期：8
• 页码：4375-4382
• 全文大小：384K
• 年卷期：0
• ISSN：1520-6882

文摘

The isotope drift encountered on short transient signals measured by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) is related to differences in detector time responses. Faraday to Faraday and Faraday to ion counter time lags were determined and corrected using VBA data processing based on the synchronization of the isotope signals. The coefficient of determination of the linear fit between the two isotopes was selected as the best criterion to obtain accurate detector time lag. The procedure was applied to the analysis by laser ablation-MC-ICPMS of micrometer sized uranium particles (1–3.5 μm). Linear regression slope (LRS) (one isotope plotted over the other), point-by-point, and integration methods were tested to calculate the ²³⁵U/²³⁸U and ²³⁴U/²³⁸U ratios. Relative internal precisions of 0.86 to 1.7% and 1.2 to 2.4% were obtained for ²³⁵U/²³⁸U and ²³⁴U/²³⁸U, respectively, using LRS calculation, time lag, and mass bias corrections. A relative external precision of 2.1% was obtained for ²³⁵U/²³⁸U ratios with good accuracy (relative difference with respect to the reference value below 1%).