Yanbei Zhu
Giovanni Mongelli
Rosa Sinisi
Yong-Hyeon Yim- 1National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
- 2Department of Sciences, University of Basilicata, Potenza, Italy
- 3National Research Council of Italy, Institute of Methodologies for Environmental Analysis (CNR-IMAA), Tito Scalo, Potenza, Italy
- 4Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
Editorial on the Research Topic
Analytical chemistry of rare earth elements (REEs)
Rare earth elements (REEs)—including Y, Sc, and lanthanides—are a group of elements attracting interests from various research fields due to general similarities and some variation in physical and chemical properties. On the one hand, REEs are treated as a set of elements tracing the chemical processes in geochemistry, marine chemistry, and environmental chemistry. On the other hand, individual REEs, with their unique physical properties, are indispensable materials in modern industry, especially for the semiconductor industry. There are multiple Research Topic published since 2020 treating REEs as functional materials (Bunzli et al., 2020; Economou-Eliopoulos et al., 2020; Li, 2020; Zhang H.J. and Zhang H., 2022) and resources (Han, 2021; Kynicky et al., 2021; Tshentu and Parajuli, 2022). The present Research Topic aims to highlight the analytical chemistry of REEs, which contributes to the development and the application of REEs in other research fields.
Four original works on analytical chemistry of REEs are collected in this Research Topic, covering high lateral resolution secondary ion mass spectrometry (NanoSIMS), inductively coupled plasma tandem quadrupole mass spectrometry (ICP-QMS/QMS), gravimetric analysis, and multi-collector inductively coupled mass spectrometry (MC-ICP-MS).
Shi et al. reported a method to analyze all REEs in silicate glasses and zircon minerals by NanoSIMS. A crater with a diameter of 7–8 μm was obtained on the sample. Separation of heavy REE from oxide of light REE was achieved at a high mass resolving power of 9,400at 10% peak height. The results of REEs in NIST SRM610 glass showed sensitivities from 3 cps/ppm/nA of Lu to 13 cps/ppm/nA of Eu. The method was applied to the determination of REEs in AS3, QGNG, and Torihama zircons, providing satisfied results in comparison to glass standard and reported data. Partition coefficients of REEs between silicate melt and zircon were obtained by combination of Torihama REE data with the whole rock data.
Zhu investigated nitrous oxide (N2O) as the reaction gas for measuring REEs by ICP-QMS/QMS. It was found that the yields of mM16O+ for Eu and Yb were apparently improved by using N2O as the reaction gas. Taking advantage of this improvement, high sensitivity measurement of the whole set of REEs including Eu and Yb was achieved, with a typical sensitivity for mono-isotopic REEs at 300,000 CPS mL/ng. The use of N2O as the reaction gas was also effective to suppress Ba related spectral interferences with the measurement of Eu, resulting in free-of-mathematic-correction measurement of Eu in natural sample.
Miura and Wada applied gravimetric analysis to evaluate the purity of high-purity La2O3 by stepwise conversions of the weighing forms, where La in the sample was respectively converted to weighing forms of La oxalate, La2O3, and La2(SO4)3, which were used to evaluate the stoichiometry for accurate gravimetric determination. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine the losses of La during the filtration process. The observed La2(SO4)3 was consistent with the theoretical composition based on the observed mass ratio of La2(SO4)3/La2O3. The purity value for the original La2O3 sample was 99.977% ± .057%, which combined the gravimetric analysis using the precipitation from the homogeneous solution and verification of the weighing forms for La compounds. Impurities in the high-purity La2O3 were determined by ICP-QMS/QMS.
By using 2-hydroxyisobutyric acid (HIBA) for group separation REEs prior to their measurements by MC-ICP-MS, Lee and Ko developed a method for accurate and precise determination of REEs (particularly, heavy REEs) concentrations in geological materials including natural waters. By using a cation exchange column (AG50W-X8 200–400 mesh) with HIBA, REEs were separated to three groups, i.e. light REEs (LREE, La-Ce-Pr-Nd), middle REEs (MREE, Sm-Eu-Gd-Tb) and heavy REEs (HREE, Dy- Ho-Er-Tm-Yb-Lu). Recovery rates of most REEs in natural water sample and rock sample exceeded 98% and 95%, respectively. This method permits free-of-spectral-interference measurement of the whole set of REEs (particularly, HREE) in geological materials, contributing to correct interpretation of geochemical implications of REEs in geological system.
Author contributions
All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.
Acknowledgments
The authors greatly appreciate Ms. Shannon Lee for her kind supports on managing of this Research Topic. We also appreciate the reviewers for their contribution to this Research Topic.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Publisher’s note
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References
Bunzli, J. C. G., Wang, X. J., and Chen, X. Y. (2020). Preface to the special issue of rare earth luminescent materials. J. Rare Earths 38, i. doi:10.1016/j.jre.2020.03.010
Economou-Eliopoulos, M., Zaccarini, F., and Garuti, G. (2020). Editorial for the special issue innovative and applied research on platinum-group and rare earth elements. Minerals 10, 493. doi:10.3390/min10060493
Han, K. N. (2021). Editorial for special issue leaching of rare earth elements from various sources. Minerals 11, 164. doi:10.3390/min11020164
Kynicky, J., Smith, M., and Salvi, S. (2021). Editorial for special issue rare earth deposits and challenges of world REE demand for high-tech and green-tech at the beginning of the 3rd millennium. Minerals 11, 378. doi:10.3390/min11040378
Li, W. (2020). Editorial for the special issue on rare earth permanent magnets. Eng 6, 101. doi:10.1016/j.eng.2019.12.010
Tshentu, Z. R., and Parajuli, D. (2022). Editorial for the special issue on recovery of precious metals, rare earth elements and special metals from spent secondary products. Minerals 12, 481. doi:10.3390/min12040481
Keywords: rare earth elements, analysis, SIMS, ICP-MS, gravimetric analysis
Citation: Zhu Y, Mongelli G, Sinisi R and Yim Y-H (2023) Editorial: Analytical chemistry of rare earth elements (REEs). Front. Chem. 10:1127842. doi: 10.3389/fchem.2022.1127842
Received: 20 December 2022; Accepted: 27 December 2022;
Published: 10 January 2023.
Edited and reviewed by:
Yuqing Miao, University of Shanghai for Science and Technology, ChinaCopyright © 2023 Zhu, Mongelli, Sinisi and Yim. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Yanbei Zhu, yb-zhu@aist.go.jp; Giovanni Mongelli, giovanni.mongelli@unibas.it; Rosa Sinisi, rosa.sinisi@imaa.cnr.it; Yong-Hyeon Yim, yhyim@kriss.re.kr