Hf and Lu isotopic reference values for the zircon standard 91500 by MC-ICP-MS
In: Chemical Geology. Elsevier: New York; London; Amsterdam. ISSN 0009-2541; e-ISSN 1872-6836, meer
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| Author keywords |
Hf isotopes; Zircon; MC-ICP-MS; Zircon standard 91500; Lu isotopes |
| Auteurs | | Top |
- Goolaerts, A.
- Mattielli, N., meer
- de Jong, J., meer
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| Abstract |
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. |
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