Re-evaluation of interferences of doubly charged ions of heavy rare earth elements on Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry

• Published in: Spectrochimica acta. Part B: Atomic spectroscopy Vol. 97; pp. 118 - 123
• Main Authors: Yang, Yue-Heng, Wu, Fu-Yuan, Xie, Lie-Wen, Chu, Zhu-Yin, Yang, Jin-Hui
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2014
• Subjects: Charging; Doubly charged ion; Erbium; Heavy rare earth interference; Interference; MC-ICP-MS isobaric interference; Rare earth elements; Reference materials; Rock; Sr isotope; Strontium; Sr isotope; MC-ICP-MS isobaric interference; Heavy rare earth interference; Doubly charged ion
• ISSN: 0584-8547; 1873-3565
• DOI: 10.1016/j.sab.2014.05.006

We re-evaluate the interference of doubly charged heavy rare earth elements during Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). A series of mixed solutions of standard reference material SRM 987, rare earth elements, and Sr separated from rock reference materials are measured to assess the influence of isobaric interferences on the MC-ICP-MS analysis of Sr isotopes. After sample dissolution, conventional cation-exchange chromatography is employed for Sr purification of rock reference materials prior to MC-ICP-MS measurement. It has been demonstrated that if the natural abundances of Er and Yb are used to correct for doubly charged ion interferences on Sr, an overcorrection results. In contrast, the use of measured doubly charged ion ratios results in an accurate and precise correction of isobaric interference. This finding is confirmed by analytical results for several certified reference materials from mafic (basaltic) to felsic (granitic) silicate rocks. It is noteworthy that, because Er is more prone to doubly charged ion formation, it dominates over Yb doubly charged ions as an interference source. •We re-investigated interference of doubly charged HREE ion on Sr isotope.•Natural abundance of Er and Yb to correct the interference leads to an overcorrection.•Er is more prone to doubly charged ion formation than Yb.