start-ver=1.4 cd-journal=joma no-vol=400 cd-vols= no-issue= article-no= start-page=51 end-page=71 dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=202507 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Lithium- and oxygen-isotope compositions of a Si-rich nebular reservoir determined from chondrule constituents in the Sahara 97103 EH3 chondrite en-subtitle= kn-subtitle= en-abstract= kn-abstract=Here we report the in situ ion-microprobe analyses of the Li- and O-isotope compositions of enstatite, FeO-rich pyroxene, olivine, glass, and cristobalite grains from six chondrule-related objects from the Sahara 97103 EH3 chondrite. The O-isotope composition of the enstatite grains scattered around the intersection between the terrestrial fractionation and primitive chondrule minerals lines. Whereas, that of olivine varied along the primitive chondrule minerals line. Based on the mineralogy, we found cristobalite formed as a result of Si saturation, instead of the reduction of FeO-rich silicates, consistent with Si-enrichment of whole rock enstatite chondrites. Based on the mineralogy and O-isotope compositions, we infer that olivines in some chondrules are relict grains. In chondrules that contained olivine, no abundant niningerite [(Mg,Fe,Mn)S] was observed. Thus, enstatite formation can be explained by the interaction of an olivine precursor with additional SiO2 (Mg2SiO4 + SiO2 ¨ Mg2Si2O6), instead of sulfidation (Mg2SiO4 + S ¨ 1/2 Mg2Si2O6 + MgS + 1/2 O2). Using the equation Mg2SiO4 + SiO2 ¨ Mg2Si2O6 and the O-isotope compositions of enstatite and olivine, the O-isotope composition of the additional SiO2 was estimated. Based on the O-isotope composition, we infer that there could be a Si-rich gas with an elevated ƒ’17O value similar to, or greater than the second trend line (ƒ’17O = 0.9 ρ) suggested by Weisberg et al. (2021), during chondrule formation. The variation in the Li-isotope compositions of enstatite and olivine grains from EH3 chondrules is smaller than that for the same phases from CV3 chondrules. The variation in the Li-isotope compositions of the enstatite and olivine grains from EH3 chondrules is also smaller than that of their O-isotope compositions. During the recycling of enstatite-chondrite chondrules, both Li- and O-isotope compositions were homogenized. Although enstatite is the major carrier of Li in EH3 chondrules, the Li-isotope composition (ƒΒ7Li) of enstatite is lower than that of whole rock EH3 chondrites, suggesting the existence of a phase with higher ƒΒ7Li. Meanwhile, the Li-isotope composition and concentration (ƒΒ7Li, [Li]) of enstatite is higher than that of olivine. The Li-isotope composition of the Si-rich gas was estimated to be ƒΒ7Li = 1 ρ, using a similar mass-balance calculation as applied for the O-isotope composition. The Li-isotope composition of the Si-rich gas from the enstatite-chondrite-chondrule forming-region, is consistent with that of whole rock EH3 chondrites, and differs significantly from that of the Si-rich gas from the carbonaceous-chondrite-chondrule forming-region (ƒΒ7Li = ?11 ρ) determined by a previous study. We speculate that the Si-rich gas in the carbonaceous-chondrite-chondrule forming-region maintained the Li-isotope heterogeneity inherited from light lithium synthesized by galactic cosmic-ray spallation in the interstellar medium. en-copyright= kn-copyright= en-aut-name=Douglas-SongTorii en-aut-sei=Douglas-Song en-aut-mei=Torii kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OtaTsutomu en-aut-sei=Ota en-aut-mei=Tsutomu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamanakaMasahiro en-aut-sei=Yamanaka en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KitagawaHiroshi en-aut-sei=Kitagawa en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TanakaRyoji en-aut-sei=Tanaka en-aut-mei=Ryoji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=PotiszilChristian en-aut-sei=Potiszil en-aut-mei=Christian kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KunihiroTak en-aut-sei=Kunihiro en-aut-mei=Tak kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= affil-num=1 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= affil-num=2 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= affil-num=3 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= affil-num=5 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= affil-num=6 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= affil-num=7 en-affil=The Pheasant Memorial Laboratory Institute for Planetary Materials, Okayama University kn-affil= en-keyword=Lithium kn-keyword=Lithium en-keyword=Oxygen kn-keyword=Oxygen en-keyword=Trace elements kn-keyword=Trace elements en-keyword=Chondrule kn-keyword=Chondrule en-keyword=Enstatite chondrite kn-keyword=Enstatite chondrite en-keyword=SIMS kn-keyword=SIMS en-keyword=Sulfidation kn-keyword=Sulfidation en-keyword=Silicification kn-keyword=Silicification END start-ver=1.4 cd-journal=joma no-vol=653 cd-vols= no-issue= article-no= start-page=119205 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=202503 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Meteoritic and asteroidal amino acid heterogeneity: Implications for planetesimal alteration conditions and sample return missions en-subtitle= kn-subtitle= en-abstract= kn-abstract=Carbonaceous chondrites (CC) and asteroid return samples contain amino acids (AA), which are essential for an origin of life on the early Earth and can provide important information concerning planetesimal alteration processes. While many studies have investigated AA from CC, separate studies have often found differing abundances for the same meteorite. Accordingly, analytical bias, differing terrestrial contamination levels and intrinsic sample heterogeneity have been proposed as potential reasons. However, current analytical techniques allow for the analysis of several mg-sized samples and can thus enable an investigation of AA heterogeneity within single meteorite specimens. Here, such an analytical technique is applied to characterise the AA in triplicate aliquots of three CCs. The results indicate that CCs are heterogenous in terms of their AA at the mm-scale. Furthermore, the results help to further constrain the effects of planetesimal alteration on organic matter and the requirements of future sample return missions that aim to obtain organic-bearing extraterrestrial materials. en-copyright= kn-copyright= en-aut-name=PotiszilChristian en-aut-sei=Potiszil en-aut-mei=Christian kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OtaTsutomu en-aut-sei=Ota en-aut-mei=Tsutomu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamanakaMasahiro en-aut-sei=Yamanaka en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KobayashiKatsura en-aut-sei=Kobayashi en-aut-mei=Katsura kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TanakaRyoji en-aut-sei=Tanaka en-aut-mei=Ryoji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NakamuraEizo en-aut-sei=Nakamura en-aut-mei=Eizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=2 en-affil=Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=3 en-affil=Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=5 en-affil=Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=6 en-affil=Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= en-keyword=Carbonaceous chondrite kn-keyword=Carbonaceous chondrite en-keyword=Heterogeneity kn-keyword=Heterogeneity en-keyword=Planetesimal kn-keyword=Planetesimal en-keyword=Aqueous alteration kn-keyword=Aqueous alteration en-keyword=Amino acid and meteorite kn-keyword=Amino acid and meteorite END start-ver=1.4 cd-journal=joma no-vol=965 cd-vols= no-issue=1 article-no= start-page=52 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240404 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Unraveling the Cr Isotopes of Ryugu: An Accurate Aqueous Alteration Age and the Least Thermally Processed Solar System Material en-subtitle= kn-subtitle= en-abstract= kn-abstract=The analysis of samples returned from the C-type asteroid Ryugu has drastically advanced our knowledge of the evolution of early solar system materials. However, no consensus has been obtained on the chronological data, which is important for understanding the evolution of the asteroid Ryugu. Here, the aqueous alteration age of Ryugu particles was determined by the Mn?Cr method using bulk samples, yielding an age of 4.13 + 0.62/?0.55 Myr after the formation of Ca?Al-rich inclusions (CAI). The age corresponds to 4563.17 + 0.60/?0.67 Myr ago. The higher 55Mn/52Cr, ƒΓ54Cr, and initial ƒΓ53Cr values of the Ryugu samples relative to any carbonaceous chondrite samples implies that its progenitor body formed from the least thermally processed precursors in the outermost region of the protoplanetary disk. Despite accreting at different distances from the Sun, the hydrous asteroids (Ryugu and the parent bodies of CI, CM, CR, and ungrouped C2 meteorites) underwent aqueous alteration during a period of limited duration (3.8 } 1.8 Myr after CAI). These ages are identical to the crystallization age of the carbonaceous achondirtes NWA 6704/6693 within the error. The ƒΓ54Cr and initial ƒΓ53Cr values of Ryugu and NWA 6704/6693 are also identical, while they show distinct ƒ’'17O values. This suggests that the precursors that formed the progenitor bodies of Ryugu and NWA 6703/6693 were formed in close proximity and experienced a similar degree of thermal processing in the protosolar nebula. However, the progenitor body of Ryugu was formed by a higher ice/dust ratio, than NWA6703/6693, in the outer region of the protoplanetary disk. en-copyright= kn-copyright= en-aut-name=TanakaRyoji en-aut-sei=Tanaka en-aut-mei=Ryoji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=RatnayakeDilan M. en-aut-sei=Ratnayake en-aut-mei=Dilan M. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=OtaTsutomu en-aut-sei=Ota en-aut-mei=Tsutomu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MiklusicakNoah en-aut-sei=Miklusicak en-aut-mei=Noah kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KunihiroTak en-aut-sei=Kunihiro en-aut-mei=Tak kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=PotiszilChristian en-aut-sei=Potiszil en-aut-mei=Christian kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=SakaguchiChie en-aut-sei=Sakaguchi en-aut-mei=Chie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=KobayashiKatsura en-aut-sei=Kobayashi en-aut-mei=Katsura kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=KitagawaHiroshi en-aut-sei=Kitagawa en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=YamanakaMasahiro en-aut-sei=Yamanaka en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=AbeMasanao en-aut-sei=Abe en-aut-mei=Masanao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=MiyazakiAkiko en-aut-sei=Miyazaki en-aut-mei=Akiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=NakatoAiko en-aut-sei=Nakato en-aut-mei=Aiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=NakazawaSatoru en-aut-sei=Nakazawa en-aut-mei=Satoru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=NishimuraMasahiro en-aut-sei=Nishimura en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=OkadaTatsuaki en-aut-sei=Okada en-aut-mei=Tatsuaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= en-aut-name=SaikiTakanao en-aut-sei=Saiki en-aut-mei=Takanao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=17 ORCID= en-aut-name=TanakaSatoshi en-aut-sei=Tanaka en-aut-mei=Satoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=18 ORCID= en-aut-name=TeruiFuyuto en-aut-sei=Terui en-aut-mei=Fuyuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=19 ORCID= en-aut-name=TsudaYuichi en-aut-sei=Tsuda en-aut-mei=Yuichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=20 ORCID= en-aut-name=UsuiTomohiro en-aut-sei=Usui en-aut-mei=Tomohiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=21 ORCID= en-aut-name=WatanabeSei-ichiro en-aut-sei=Watanabe en-aut-mei=Sei-ichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=22 ORCID= en-aut-name=YadaToru en-aut-sei=Yada en-aut-mei=Toru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=23 ORCID= en-aut-name=YogataKasumi en-aut-sei=Yogata en-aut-mei=Kasumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=24 ORCID= en-aut-name=YoshikawaMakoto en-aut-sei=Yoshikawa en-aut-mei=Makoto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=25 ORCID= en-aut-name=NakamuraEizo en-aut-sei=Nakamura en-aut-mei=Eizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=26 ORCID= affil-num=1 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=2 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=3 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=5 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=6 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=7 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=8 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=9 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=10 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=11 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=12 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=13 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=14 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=15 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=16 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=17 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=18 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=19 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=20 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=21 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=22 en-affil=Department of Earth and Planetary Sciences, Nagoya University kn-affil= affil-num=23 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=24 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=25 en-affil=Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency kn-affil= affil-num=26 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210517 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Element concentrations of chondrule constituents, supplement to: Tak Kunihiro et al. (2021): The trace element composition of chondrule constituents: Implications for sample return methodologies and the chondrule silicate reservoir. Meteorit Planet Sci en-subtitle= kn-subtitle= en-abstract= kn-abstract= en-copyright= kn-copyright= en-aut-name=KunihiroTak en-aut-sei=Kunihiro en-aut-mei=Tak kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OtaTsutomu en-aut-sei=Ota en-aut-mei=Tsutomu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamanakaMasahiro en-aut-sei=Yamanaka en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NakamuraEizo en-aut-sei=Nakamura en-aut-mei=Eizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=2 en-affil=The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=3 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=43 cd-vols= no-issue=1 article-no= start-page=147 end-page=161 dt-received= dt-revised= dt-accepted= dt-pub-year=2018 dt-pub=20181025 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Determination of Abundances of Fifty-Two Elements in Natural Waters by ICP-MS with Freeze-Drying Pre-concentration en-subtitle= kn-subtitle= en-abstract= kn-abstract= To precisely determine the abundances of fifty-two elements found within natural water samples, with mass fractions down to fg g(-1) level, we have developed a method which combines freeze-drying pre-concentration (FDC) and isotope dilution internal standardisation (ID-IS). By sublimation of H2O, the sample solution was reduced to < 1/50 of the original volume. To determine element abundance with accuracy better than 10%, we found that for solutions being analysed by mass spectrometry the HNO3 concentration should be > 0.3 mol l(-1) to avoid hydrolysis. Matrix-affected signal suppression was not significant for the solutions with NaCl concentrations lower than 0.2 and 0.1 cg g(-1) for quadrupole ICP-MS and sector field ICP-MS, respectively. The recovery yields of elements after FDC were 97-105%. The detection limits for the sample solutions prepared by FDC were <= 10 pg g(-1), except for Na, K and Ca. Blanks prepared using FDC were at pg-levels, except for eleven elements (Na, Mg, Al, P, Ca, Mn, Fe, Co, Ni, Cu and Zn). The abundances of fifty-two elements in bottled drinking water were determined from five different geological sources with mass fractions ranging from the fg g(-1) to mu g g(-1) level with high accuracy. en-copyright= kn-copyright= en-aut-name=HoangQue D. en-aut-sei=Hoang en-aut-mei=Que D. kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KunihiroTak en-aut-sei=Kunihiro en-aut-mei=Tak kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SakaguchiChie en-aut-sei=Sakaguchi en-aut-mei=Chie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YamanakaMasahiro en-aut-sei=Yamanaka en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KitagawaHiroshi en-aut-sei=Kitagawa en-aut-mei=Hiroshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NakamuraEizo en-aut-sei=Nakamura en-aut-mei=Eizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=2 en-affil=The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= affil-num=3 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=5 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=6 en-affil=The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University kn-affil= en-keyword=pre-concentration kn-keyword=pre-concentration en-keyword=freeze-drying kn-keyword=freeze-drying en-keyword=ID-IS kn-keyword=ID-IS en-keyword=natural water kn-keyword=natural water en-keyword=drinking water kn-keyword=drinking water END start-ver=1.4 cd-journal=joma no-vol=43 cd-vols= no-issue=4 article-no= start-page=611 end-page=633 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190320 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Method to Suppress Isobaric and Polyatomic Interferences for Measurements of Highly Siderophile Elements in Desilicified Geological Samples en-subtitle= kn-subtitle= en-abstract= kn-abstract= 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. en-copyright= kn-copyright= en-aut-name=ZhouXiaoyu en-aut-sei=Zhou en-aut-mei=Xiaoyu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=TanakaRyoji en-aut-sei=Tanaka en-aut-mei=Ryoji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamanakaMasahiro en-aut-sei=Yamanaka en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SakaguchiChie en-aut-sei=Sakaguchi en-aut-mei=Chie kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=NakamuraEizo en-aut-sei=Nakamura en-aut-mei=Eizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=2 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=3 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=4 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= affil-num=5 en-affil=The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University kn-affil= en-keyword=highly siderophile elements kn-keyword=highly siderophile elements en-keyword=desilicification kn-keyword=desilicification en-keyword=isotope dilution method kn-keyword=isotope dilution method en-keyword=high resolution ICP-MS kn-keyword=high resolution ICP-MS en-keyword=N-TIMS kn-keyword=N-TIMS END