TY - JOUR
T1 - A Method to Suppress Isobaric and Polyatomic Interferences for Measurements of Highly Siderophile Elements in Desilicified Geological Samples
AU - Zhou, Xiaoyu
AU - Tanaka, Ryoji
AU - Yamanaka, Masahiro
AU - Sakaguchi, Chie
AU - Nakamura, Eizo
N1 - Funding Information:
We appreciate the editor T.C. Meisel for his valuable discussions about the reference materials and his heplful editorial comments on the manuscript. Two anonymous reviewers are thanked for their constructive comments which significantly improved the manuscript. We also thank A. Makishima, K. Kobayashi, T. Kunihiro, H. Kitagawa, T. Ota and K. Tait for discussions, and K. Tanaka for assistance in the laboratory. We are grateful to G. E. Bebout, C. Potiszil and M.-L. Avramescu for improving the initial manuscript. This study was funded by Ministry of Education, Culture, Sports, Science and Technology (MEXT, Japan) through the programme ?Establishment of the international research-education centre for pioneering planetary material science? and by the Grant-in-Aid for Scientific Research from Japan Society for the Promotion of Science (Grant Number 16K05578).
Publisher Copyright:
© 2019 The Authors. Geostandards and Geoanalytical Research © 2019 International Association of Geoanalysts
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Sample decomposition using inverse aqua regia at elevated temperatures and pressures (e.g., Carius tube or high-pressure asher) is the most common method used to extract highly siderophile elements (HSEs: Ru, Rh, Pd, Re, Os, Ir, Pt and Au) from geological samples. Recently, it has been recognised that additional HF desilicification is necessary to better recover HSEs, potentially contained within silicate or oxide minerals in mafic samples, which cannot be dissolved solely by inverse aqua regia. However, the abundance of interfering elements tends to increase in the eluent when conventional ion-exchange purification procedures are applied to desilicified samples. In this study, we developed an improved purification method to determine HSEs in desilicified samples. This method enables the reduction of the ratios of isobaric and polyatomic interferences, relative to the measured intensities of HSE isotope masses, to less than a few hundred parts per million. Furthermore, the total procedural blanks are either comparable to or lower than conventional methods. Thus, this method allows accurate and precise HSE measurements in mafic and ultramafic geological samples, without the need for interference corrections. Moreover, the problem of increased interfering elements, such as Zr for Pd and Cr for Ru, is circumvented for the desilicified samples.
AB - Sample decomposition using inverse aqua regia at elevated temperatures and pressures (e.g., Carius tube or high-pressure asher) is the most common method used to extract highly siderophile elements (HSEs: Ru, Rh, Pd, Re, Os, Ir, Pt and Au) from geological samples. Recently, it has been recognised that additional HF desilicification is necessary to better recover HSEs, potentially contained within silicate or oxide minerals in mafic samples, which cannot be dissolved solely by inverse aqua regia. However, the abundance of interfering elements tends to increase in the eluent when conventional ion-exchange purification procedures are applied to desilicified samples. In this study, we developed an improved purification method to determine HSEs in desilicified samples. This method enables the reduction of the ratios of isobaric and polyatomic interferences, relative to the measured intensities of HSE isotope masses, to less than a few hundred parts per million. Furthermore, the total procedural blanks are either comparable to or lower than conventional methods. Thus, this method allows accurate and precise HSE measurements in mafic and ultramafic geological samples, without the need for interference corrections. Moreover, the problem of increased interfering elements, such as Zr for Pd and Cr for Ru, is circumvented for the desilicified samples.
KW - N-TIMS
KW - desilicification
KW - high-resolution ICP-MS
KW - highly siderophile elements
KW - isotope dilution method
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U2 - 10.1111/ggr.12280
DO - 10.1111/ggr.12280
M3 - Article
AN - SCOPUS:85068677626
VL - 43
SP - 611
EP - 633
JO - Geostandards and Geoanalytical Research
JF - Geostandards and Geoanalytical Research
SN - 0150-5505
IS - 4
ER -