Hf and Lu isotopic reference values for the zircon standard 91500 by MC-ICP-MS

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• 作者：Goolaerts ; Arnaud ; Mattielli ; Nadine ; de Jong ; Jeroen ; Weis ; Dominique ; Scoates ; James S.
• 关键词：Hf isotopes ; Zircon ; MC-ICP-MS ; Zircon standard 91500 ; Lu isotopes
• 刊名：Chemical Geology
• 出版年：2004
• 出版时间：May 28, 2004
• 年：2004
• 卷：206
• 期：1-2
• 页码：1-9
• 全文大小：236 K

文摘

The Hf and Lu isotopic ratios of the zircon standard 91500 have been redefined by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The chemical protocol consists of a high-pressure and high-temperature acid dissolution of zircon followed by optimized two-step ion-exchange chromatography with an overall recovery better than 94 % . Instrumental calibration involved an extensive characterization of standard solutions for Hf [JMC-475 250 ppb: ¹⁷⁶Hf/¹⁷⁷Hf=0.282161±16 (2 S.D.)] and Lu [JMC standard 50 ppb: ¹⁷⁵Lu/¹⁷⁶Lu=37.72±2 (2 S.D.)]. A total of 59 Hf isotopic measurements on the zircon standard 91500, including four independent dissolutions and purifications, were carried out on two Nu Plasma MC-ICP-MS instruments. The average ¹⁷⁶Hf/¹⁷⁷Hf is 0.282302±8 (2 S.D.) and the two MC-ICP-MS instruments give overlapping results within error. These high precision data [external error: 27 ppm (2 S.D.) for 59 measurements and 10 ppm for a single day; internal error: 10 ppm (2 S.D.)] are reproducible between duplicates and underscore the stability of the analytical protocol. The Lu isotopic composition of the zircon standard 91500 has also been redefined: ¹⁷⁵Lu/¹⁷⁶Lu=37.74±8 (2 S.D.). With the growing use of in situ measurement techniques using MC-ICP-MS technology, such precise reference values will be important for the calibration of laser ablation analyses in the future.