研究者詳細 - 牧嶋　昭夫

論文 - 牧嶋　昭夫

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CBコンドライトのMn-Cr年代

山下勝行, 山川茜, 丸山誠史, 牧嶋昭夫, 中村栄三

日本地球化学会年会要旨集 56 71 - 71 2009年

出版者・発行元：一般社団法人日本地球化学会

Mn-Cr年代測定法は初期太陽系物質の年代を精度良く求めることのできる手法として注目されている。しかしMn-Cr年代を絶対年代に置き換えるためには絶対年代と53Mn/55Mn初生比の両方が精度良く求められた「基準点（anchor）」が必要である。本研究では正確なU-Pb年代が報告されているCBコンドライトGujbaのコンドリュールとメタルスフェリュールのCr同位体分析を行ったのでその結果について報告する。

DOI： 10.14862/geochemproc.56.0.71.0

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同位体希釈法と内標準法を併用した、ICP質量分析法によるLi, Be, Rb, Sr, Y, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb, Th, Uの同時測定法の開発

牧嶋昭夫, 北川宙, 坂口千恵, 中村栄三

日本鉱物学会・学術講演会,日本岩石鉱物鉱床学会学術講演会講演要旨集 2004 237 - 237 2004年9月

Determination of lithium contents in silicates by isotope dilution ICP-MS and its evaluation by isotope dilution thermal ionisation mass spectrometry 査読

Takuya Moriguti, Akio Makishima, Eizo Nakamura

Geostandards and Geoanalytical Research 28 ( 3 ) 371 - 382 2004年

掲載種別：研究論文（学術雑誌）

A precise and simple method for the determination of lithium concentrations in small amounts of silicate sample was developed by applying isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS). Samples plus a Li spike were digested with HF-HClO4, dried and diluted with HNO3, and measured by ICP-MS. No matrix effects were observed for 7Li/6Li in rock solutions with a dilution factor (DF) of ≥ 97 at an ICP power of 1.7 kW. By this method, the determination of 0.5 μg g-1 Li in a silicate sample of 1 mg can be made with a blank correction of < 1%. Lithium contents of ultrabasic to acidic silicate reference materials (JP-1, JB-2, JB-3, JA-1, JA-2, JA-3, JR-1 and JR-2 from the Geological Survey of Japan, and PCC-1 from the US Geological Survey) and chondrites (three different Allende and one Murchison sample) of 8 to 81 mg were determined. The relative standard deviation (RSD) was typically < 1.7%. Lithium contents of these samples were further determined by isotope dilution-thermal ionisation mass spectrometry (ID-TIMS). The relative differences between ID-ICP-MS and ID-TIMS were typically < 2%, indicating the high accuracy of ID-ICP-MS developed in this study.

DOI： 10.1111/j.1751-908X.2004.tb00756.x

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Comment on "determination of total sulfur at microgram-per-gram levels in geological materials by oxidation of sulfur into sulfate with in situ generation of bromine using isotope dilution high resolution ICPMS" 招待

W. Robert Kelly, Robert D. Vocke, Jacqueline L. Mann, Akio Makishima, Eizo Nakamura

Analytical Chemistry 74 ( 24 ) 6430 - 6432 2002年12月

Determination of chromium, nickel, copper and zinc in milligram samples of geological materials using isotope dilution high resolution inductively coupled plasma-mass spectrometry 査読

Akio Makishima, Katsura Kobayashi, Eizo Nakamura

Geostandards Newsletter 26 ( 1 ) 41 - 51 2002年

担当区分：筆頭著者掲載種別：研究論文（学術雑誌）

A simple and accurate method for the determination of Cr, Ni, Cu and Zn at μg g-1 levels in milligram-sized bulk silicate materials is reported using isotope dilution high-resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) with a flow injection system. Silicate samples with Cr, Ni, Cu and Zn spikes were digested with HF-HBr and Br2, and subsequently decomposed at 518 K in a Teflon bomb. In this procedure, all sulfides and chromite, major hosts of these elements, were completely decomposed, thus allowing for isotope equilibration between the sample and spike. Magnesium and Al fluorides formed after the digestion of the sample were removed by centrifugation, and the supernatant was directly aspirated into a HR-ICP-MS at a mass resolution of 7500, where interfering oxide ions, ArO +, CaO+, TiO+, CrO+ and VO +, were separated from Cr+, Ni+, Cu+ and Zn+. No matrix effects were observed down to a dilution factor of 50. Detection limits for these elements in silicate samples were < 0.04 μg g-1. The effectiveness of the technique was demonstrated by the analysis of 13 to 40 mg test portions of USGS and GSJ silicate reference materials with a major element composition ranging from andesite to peridotite, in addition to 8-23 mg of the Smithsonian reference Allende. Both the reproducibility and the deviation from the reference value for most reference materials of various rock types were < 9%, and thus confirm that the method gives accurate analytical results for small sample sizes over a wide range of Cr, Ni, Cu and Zn contents. This method is, therefore, suitable for analysing small and/or precious bulk samples, such as meteorites, mantle peridotites and mineral separates, and for the characterisation of silicate and sulfide minerals for use as calibration samples in secondary ion mass spectrometry or laser ablation ICP-MS.

DOI： 10.1111/j.1751-908X.2002.tb00622.x

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Formation and suppression of AlF<inf>3</inf> during HF digestion of rock samples in Teflon bomb for precise trace element analyses by ICP-MS and ID-TIMS 査読

Hiroyuki Takei, Tetsuya Yokoyama, Akio Makishima, Eizo Nakamura

Proceedings of the Japan Academy Series B: Physical and Biological Sciences 77 ( 1 ) 13 - 17 2001年1月

掲載種別：研究論文（学術雑誌）

An aluminum fluoride, AlF3, forms during HF digestion of felsic rock samples, for trace element and isotope geochemistry, which use a Teflon bomb at high temperature and pressure. The AlF3 incorporates trace elements (Rb, Sr, Y, Cs, Ba, REE, Pb, Th, and U), and can not be decomposed by conventional methods such as evaporation with HClO4. The production of this AlF3 results in lower yields and poor accuracy in analyses of these trace elements by ICP-MS. The formation of AlF3 is controlled by the chemical composition of the rock samples, in particular, AlF3 does not form during decomposition of mafic samples with relatively high (Mg+Ca)/Al ratios. We have developed a new method to suppress the AlF3 formation, in which excess Mg is added to the sample prior to acid digestion in the bomb. This new method makes it possible to accurately determine the trace element compositions of higher-Al rock samples with lower concentrations of Mg and Ca (e.g. rhyolite and granite). In the trace element analyses by TIMS with isotope dilution techniques (ID-TIMS), AlF3 formation hinders the achievement of isotope equilibrium, resulting in erroneous results. However, the Mg-addition method removed this problem by suppression of AlF3 formation.

DOI： 10.2183/pjab.77.13

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Determination of titanium at μg g^-1 levels in milligram amounts of silicate materials by isotope dilution high resolution inductively coupled plasma mass spectrometry with flow injection 査読

Akio Makishima, Eizo Nakamura

Journal of analytical atomic spectrometry 15 ( 3 ) 263 - 267 2000年

担当区分：筆頭著者掲載種別：研究論文（学術雑誌）

An accurate method for the determination of Ti at μg g-1 levels in milligram amounts of silicate materials with isotope dilution high-resolution inductively coupled plasma mass spectrometry equipped with flow injection system (ID-FI-HR-ICP-MS) is presented. The chemical procedure requires HF digestion of the sample with the Ti spike, subsequent evaporation and dissolution of Ti with HF in order to separate from Mg and Ca fluorides formed after the digestion of the sample. A 10 mg silicate sample containing 0.002% TiO2 was measured with a blank correction of <5%. To demonstrate the applicability of this method, peridotite reference materials, PCC-1 and DTS-1, from the US Geological Survey (USGS) and JP-1 from the Geological Survey of Japan (GSJ) were analyzed (12-33 mg), to determine TiO2 content. The reproducibility was 3% for these peridotites with TiO2 contents of 0.003-0.004%. This method also gave TiO2 contents in BCR-1, BHVO-1 and AGV-1 from USGS and JB-1, -2, -3, JA-1, -2, and -3 from GSJ with reproducibility of 1-5% using test portions of 6-18 mg.

DOI： 10.1039/a909020g

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Determination of molybdenum, antimony and tungsten at sub μg g ^-1 levels in geological materials by ID-FI-ICP-MS 査読

Akio Makishima, Eizo Nakamura

Geostandards Newsletter 23 ( 2 ) 137 - 148 1999年

担当区分：筆頭著者掲載種別：研究論文（学術雑誌）

We have developed a rapid and accurate method for the determination of Mo, Sb and W in geological samples using isotope dilution inductively coupled plasma-mass spectrometry with a flow injection system (ID-FI-ICP-MS). The chemical procedure requires HF digestion of the sample with a Mo-Sb-W mixed spike, subsequent evaporation and dissolution of Mo, Sb and W from Mg and Ca fluorides with HF. Recovery yields of Mo, Sb and W in the extraction were > 94% for samples of peridotite, basalt and andesite composition, with the exception of W in samples of peridotite composition for which recovery was 81%. No matrix effects were observed in the determination of the isotope ratios of Mo, Sb and W in solutions prepared from peridotite, basalt and andesite samples down to a dilution factor of 100. Detection limits of Mo, Sb and W in silicate materials were at the several ng g-1 level. Analysis of the silicate reference materials PCC-1, DTS-1, BCR-1, BHVO-1, AGV-1 from the US Geological Survey and JP-1, JB-1, -2, -3, JA-1, -2, and -3 from the Geological Survey of Japan as well as the Smithsonian reference Allende powder yielded reliable Mo, Sb and W concentrations. The repeatability in the analysis of basalts and andesites was < 9%. This technique requires only 0.2 ml sample solution, and is therefore suitable for analyzing small and/or precious samples such as meteorites, mantle peridotites and their mineral separates.

DOI： 10.1111/j.1751-908X.1999.tb00569.x

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Separation of thorium and uranium from silicate rock samples using two commercial extraction chromatographic resins 査読

Tetsuya Yokoyama, Akio Makishima, Eizo Nakamura

Analytical Chemistry 71 ( 1 ) 135 - 141 1999年

掲載種別：研究論文（学術雑誌）

A new chemical separation technique to isolate Th and U from silicate rocks was established by using two kinds of commercial extraction Chromatographic resins. In the first column procedure, with U/TEVA·spec resin, almost all elements except Th and U were eluted by 4 M HNO3. Th was then separated by using 5 M HC1, and U was finally isolated by successive addition of 0.1 M HNO3. A significant amount of Zr still remained in the Th fraction, which was then further purified in the second column stage using TEVA·spec resin. In the second procedure, Zr was eluted first by using 2 M HNO3, and then Th was collected by 0.1 M HNO3. Both the Th and U fractions obtained by these procedures were sufficiently pure for thermal ionization mass spectrometric (TIMS) analysis. Recovery yields of Th and U exceeded 90%, and total blanks were <19 pg for Th and <10 pg for U. Our method has advantages over previous methods in terms of matrix effects, tailing problems, and degree of isolation. Since Th and U are effectively separated without suffering any matrix interference from coexisting cations and anions, this technique can be used not only for the analysis of igneous rock samples but also for the analysis of soils, marine sediments, carbonates, phosphates and seawater, groundwater, and surface water. © 1998 American Chemical Society.

DOI： 10.1021/ac9805807

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Sr, Nd and Pb isotope systematics of Akagi volcano, Northeast Japan: Implications for interaction between island arc magma and lower crust 査読

Katsura Kobayashi, Eizo Nakamura, Tomoyuki Shibata, Akio Makishima

Proceedings of the Japan Academy Series B: Physical and Biological Sciences 73 ( 5 ) 69 - 73 1997年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

Isotopic compositions of Sr, Nd and Pb and REE concentrations have been determined for samples from "isotopically anomalous" Akagi volcano locating on the volcanic front of Northeast Japan Arc. The Sr isotopic compositions show a large variation with highly enriched isotope character (87Sr/86Sr=0.7060 to 0.7088) compared to those from other volcanoes on the front. The Nd isotopic compositions, ranging from εNd = -0.40 to -8.6, have a negative correlation with the Sr isotopic compositions. The Pb isotopic data along with Sr and Nd isotope systematics clearly indicate that the isotopic variations of Akagi volcano were caused by a two-component mixing between an end member isotopically similar to the primary magma on the volcanic front of Northeast Japan Arc and a lower crustal component. Chondrite-normalized REE patterns of Akagi samples show U-shaped, HREE-depleted pattern with positive Eu anomaly. Such REE features may have been developed by fractionation of amphibole formed by the reaction between a fluid-rich magma and clinopyroxene in granulitic lower crust. The fluid-rich magma could be originated from a highly metasomatized mantle wedge caused by the dehydration of oceanic slabs of the Pacific plate and the overlapping Philippine Sea Plate. Such a unique tectonic setting could result in higher water supply to the source region of magma than normal circumstances and thereby generating fluid-rich magma which could enhance assimilation of lower crust beneath Akagi volcano.

DOI： 10.2183/pjab.73.69

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Suppression of matrix effects in ICP-MS by high power operation of ICP: Application to precise determination of Rb, Sr, Y, Cs, Ba, REE, Pb, Th and U at ng g^-1 levels in milligram silicate samples 査読

Akio Makishima, Eizo Nakamura

Geostandards Newsletter 21 ( 2 ) 307 - 319 1997年

担当区分：筆頭著者掲載種別：研究論文（学術雑誌）

We found that the suppression of signals for 88Sr, 140Ce and 238U in rock solution caused by rock matrix in ICP-MS (matrix effects) was reduced at high power operation (1.7 kW) of the ICP. To make the signal suppression by the matrix negligible, minimum dilution factors (DF) of the rock solution for Sr, Ce and U were 600, 400 and 113 at 1.1, 1.4 and 1.7 kW, respectively. Based on these findings, a rapid and precise determination method for Rb, Sr, Y, Cs, Ba, REE, Pb, Th and U using Fl (flow injection)-ICP-MS was developed. The amount of the sample solution required for FI-ICP-MS was 0.2 ml, so that 1.8 mg sample was sufficient for analysis with a detection limit of several ng g-1. Using this method, we determined the trace element concentrations in the USGS rock reference materials, DTS-1, PCC-1, BCR-1 and AGV-1, and the GSJ rock reference materials, JP-1, JB-1, -2, -3, JA-1, -2 and -3. The reproducibilities (RSD%) in replicate analyses (n=5) of BCR-1, AGV-1, JB-1, -2, -3, JA-1, -2, and -3 were < 6%, and typically 2.5%. The difference between the average concentrations of this study for BCR-1 and those of the reference values were < 2%. Therefore, it was concluded that the method can give reliable data for trace elements in silicate rocks.

DOI： 10.1111/j.1751-908X.1997.tb00678.x

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インコンパティブル元素の挙動の解明へ向けた，新しい実験的・実証的手法の開発招待査読

牧嶋昭夫

地球化学 31 27 - 34 1997年

同位体地球化学から見たアイスランド I. アイスランドホットスポットの同位体地球化学的特徴査読

牧嶋昭夫

岩鉱 : 岩石鉱物鉱床学会誌 : journal of mineralogy, petrology and economic geology 90 ( 11 ) 379 - 387 1995年11月

同位体地球化学から見たアイスランド. II. アイスランドのフェルシックな火山岩の成因. 査読

牧嶋昭夫

岩鉱 90 413 - 413 1995年

p-核種の生成とその同位体比異常査読

牧嶋昭夫, 其魯, 増田彰正

地球化学 26 ( 1 ) 41 - 50 1992年

担当区分：筆頭著者記述言語：日本語出版者・発行元：日本地球化学会

The origin of p-isotopes (proton rich isotopes) and their isotopic anomalies are reviewed in this article. The p-isotopes (⁸⁴Sr,¹²⁴Xe, ¹³⁰Ba, ¹⁴⁴Sm, ¹⁹⁶Hg, etc.) are heavy isotopes (A≧74) which cannot be synthesized by s-process or r-process. The p-isotopes are considered to be produced by the transmutation of heavy elements into lighter p-isotopes via a series of (γ, n), (γ, p) and (γ, α) reactions in supernovae. We can constrain the site and the condition of nucleosynthesis in supernovae from abundances of the p-isotopes. The isotopic anomalies of the p-isotopes of Xe, Cd and Sn are found in acid residues of the Allende carbonaceous chondrite. The anomalies of ⁸⁴Sr and ¹⁴⁴Sm are also found in the Allende FUN inclusions. They are considered to be presolar origin. The anomalies of ¹⁹⁶Hg are found, however, their origin still remains enigmatic. The anomaly of Mo isotopic abundances is found in the Sikhote-Alin iron meteorite. The anomaly can be explained by (γ, n) reaction chains of Mo. The further study of the Mo anomaly will give us interesting informations not only about the p-process, but also about the r-process effect on ⁹³Nb, the double β^--decay of ⁹⁶Zr, and the (γ, n) reaction chain of ⁹⁹Tc.

DOI： 10.14934/chikyukagaku.26.41

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Calibration of Faraday cup efficiency in a multicollector mass spectrometer 査読

Akio Makishima, Eizo Nakamura

Chemical Geology 94 ( 2 ) 105 - 110 1991年

担当区分：筆頭著者掲載種別：研究論文（学術雑誌）

Faraday cup efficiencies (FCE's) in the multicollector mass spectrometer were examined with a static multicollcction technique. The relative Faraday cup efficiency (RFCE) was estimated by measurement of Nd-isotopc ratios with five different cup configurations. The application of RFCE correction to the static multicollection technique will increase the reliability of analytical results by eliminating the errors caused by differences in FCE's, and will also enable us to distinguish which Faraday cups are damaged and should be renewed. © 1991, All rights reserved.

DOI： 10.1016/S0009-2541(10)80022-1

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ランタンーセリウム法の地球化学査読

牧嶋昭夫, 中村栄三, 増田彰正

火山 36 161 - 175 1991年

Determination of gallium in pure aluminum by isotope dilution analysis with solvent extraction using inductively coupled plasma mass spectrometry 査読

Akio Makishima, Isamu Inamoto, Koichi Chiba

Applied Spectroscopy 44 ( 1 ) 91 - 95 1990年

担当区分：筆頭著者掲載種別：研究論文（学術雑誌）

Isotope dilution analysis with inductively coupled plasma mass spectrometry (ICP-MS) was applied to the determination of gallium in pure aluminum. Furthermore, a solvent extraction procedure was combined with isotope dilution analysis as a preconcentration technique in order to determine ultra-trace levels of gallium with high precision. The accuracy and the precision of isotope dilution analysis using ICP-MS were compared with those of conventional standard addition analysis using ICP-MS. Isotope dilution analysis gave more accurate and precise results than did standard addition analysis. Isotope dilution analysis with solvent extraction made it possible to measure 0.029 μg/g gallium in 99.999% aluminum with analytical errors at less than 3%.

DOI： 10.1366/0003702904085840

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セリウム同位体比測定と年代学への応用における諸問題査読

牧嶋昭夫

Journal of the Mass Spectrometry Society of Japan 38 ( 4 ) 165 - 173 1990年

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）出版者・発行元：The Mass Spectrometry Society of Japan

Tanaka and Masuda¹⁾ first applied lanthanum-cerium isotope systematics to geochronology in 1982, using β-decay of ¹³⁸La. In this systematics, it is necessary to measure cerium isotope ratio (ex. ¹³⁸Ce/¹⁴²Ce) with precision better than 0.01% because of long half life and low abundance of ¹³⁸La. Many studies have been done to improve the precision and accuracy of the Ce isotope analysis. But there are some problems in the analysis, such as long data acquisition time and requirement of large amount of cerium. When the La-Ce systematics is used as a geochemical tracer or in geochronology, β-decay constant of ¹³⁸La is a very important factor. However, the decay constant is still in controversy so that age dating results using the La-Ce isotope systematics are less convinced compared with those of Sm-Nd and Rb-Sr systematics.<br>In this paper, precise measurements of cerium isotope ratios and geochronological applications are reviewed and their problems are pointed out.

DOI： 10.5702/massspec.38.165

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