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1.
Takuya Moriguti Akio Makishima Eizo Nakamura 《Geostandards and Geoanalytical Research》2004,28(3):371-382
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 7 Li/6 Li 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. 相似文献
2.
Ingrid Raczek Brigitte Stoll Albrecht W. Hofmann Klaus Peter Jochum 《Geostandards and Geoanalytical Research》2001,25(1):77-86
Different batches of the new US Geological Survey (USGS) reference materials (RMs) BCR-2, BHVO-2, AGV-2, DTS-2 and GSP-2 and the original USGS RMs BCR-1, BHVO-1, AGV-1, DTS-1 and GSP-1 have been analysed by isotope dilution using thermal ionisation mass spectrometry (ID-TIMS) and by multi-ion counting spark source mass spectrometry (MIC-SSMS). The concentrations of K, Rb, Sr, Ba and the rare earth elements were determined with overall analytical uncertainties of better than 1% (ID-TIMS) and 3% (MIC-SSMS). The analyses of different aliquots and batches of BCR-2, BHVO-2, AGV-2 and GSP-2, respectively, agree within 1%, i.e. approximately the analytical uncertainties of the data. This indicates an homogeneous distribution of the trace elements in these RMs. Differences in element concentrations of up to 17% in different aliquots of the depleted RM DTS-2 are outside the analytical uncertainty of our data. They may be attributed to a slightly heterogeneous distribution of trace elements in this dunite sample. Our trace element data for BCR-2, BHVO-2, AGV-2 and GSP-2 agree within about 3% with preliminary reference values published by the USGS. They also agree within 1-6% with those of the original RMs BCR-1, BHVO-1, AGV-1 and GSP-1. Large compositional differences are found between DTS-2 and DTS-1, where the concentrations of K, Rb, Sr and the light REE differ by factors of 2 to 24. 相似文献
3.
The sulfur concentration has been determined in five bauxite and two sediment NIST Standard Reference Materials (SRM) by isotope dilution thermal ionization mass spectrometry (ID-TIMS). Two outside laboratories had indicated that the original certified values in the bauxites SRMs were too high by as much as 93 percent. The ID-TIMS determinations reported here confirm that the certified values on all bauxites contained a positive bias. The sulfur concentrations obtained in this study are the following (in μgS/g, dry weight basis): SRM 69b - 2208 ± 25, SRM 696 - 601 ± 8, SRM 697 - 308 ± 7, SRM 698 - 575 ± 16 and SRM 600 - 622 ± 24. The values for the sediment samples are the following (in weight percent sulfur dry weight basis): SRM 2704 - 0.3970 ± 0.0039 and SRM 1941 - 1.717 ± 0.016. 相似文献
4.
Molybdenum concentrations in USGS reference materials and marine sediments have been measured using ICP-AES following dissolution of samples in HF-HNO3 -HCl with final aliquots made in 1 mol l−1 HCl. The concentrations determined at one of the recommended wavelengths, 281.615 nm, are found to be severely affected by a spectral interference from Al, leading to inaccurate analytical results. At an alternative wavelength, 202.030 nm, the Mo emission signal is attenuated in the window size 0.094 nm due to the presence of an Fe line (202.074 nm), thus affecting the analytical sensitivity of measurements. The attenuation of the emission signal at 202.030 nm could severely limit the determination of Mo in geological samples. 相似文献
5.
We present a new method that determines precisely and accurately rare earth elements (REE) at the sub-ng g-1 level in ultramafic rocks based on acid dissolution and quadrupole ICP-MS with systematic interference corrections on each sample. The method is demonstrated by analyses of the international geochemical reference materials, PCC-1 (peridotite), DTS-1 (dunite) and DTS-2 (dunite) provided by the United States Geological Survey (USGS), and JP-1 (peridotite) issued by the Geological Survey of Japan (GSJ). Detection limits, as rock equivalent, were calculated to be 0.01-0.08 ng g-1 for our instrument, which is sufficiently low compared to the REE concentrations of ultramafic rocks. In addition, procedural blanks of the proposed method were 0.2-5 pg, which is negligible even for the ultra-low level REE determinations. Reproducibility obtained from separate dissolutions and measurements of USGS DTS-2 and GSJ JP-1 was 3-6%, which corresponds to the high-precision data obtained by ID-TIMS or magnetic sector field ICP-MS with a desolvating nebuliser. The REE data determined exhibit smooth chondrite-normalised REE patterns for all of the tested geochemical reference materials, and the abundances are in good agreement with recently published data. 相似文献
6.
Paul R.D. Mason Kym E. Jarvis Hilary Downes Riccardo Vannucci 《Geostandards and Geoanalytical Research》1999,23(2):157-172
Incompatible trace element abundances have been determined in mantle-derived clinopyroxenes by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) in a comparative study with established microanalytical and bulk techniques. Individual clinopyroxene grains were sampled for the laser ablation study from sieved mineral separate fractions, from which similar mineral grains had been previously extracted for microprobe (SIMS) and bulk (INAA and ID-TIMS) analysis. Mineral grains were ablated with variable degrees of surface spatial resolution (50-200 μm) in order to maximise ICP-MS analyte count rates and to improve detection limits. A comparison of results from the different techniques reveals that for the most homogeneous samples LA-ICP-MS can achieve excellent levels of agreement with other techniques (10%) and good precision for most of the studied elements (1-5% RSD). Variations in calculated concentrations by LA-ICP-MS confirm inter- and intra-mineral heterogeneity determined by SIMS, reflecting changes in sample composition and texture. The long-term reproducibility of the technique is shown by the consistency of results for one sample analysed on thirteen occasions over a period of nine months. 相似文献
7.
M. Koide V.F. Hodge J.S. Yang M. Stallard E.G. Goldberg J. Calhoun K.K. Bertine 《Applied Geochemistry》1986,1(6)
Four metals, Re, Au, Ag and Mo, whose dissolved forms in seawater can potentially be reduced to insoluble states, have been measured in a variety of solids depositing under anoxic conditions: hydrothermal sulfides; coastal sediments; and phosphorites. For comparative purposes these elements have also been determined in ferromanganese minerals and pelagic sediments which have accumulated under oxidizing conditions. Rhenium appears to be a unique sentinel for identifying reducing depositional environments, where enrichments of greater than three orders of magnitude above crustal concentrations are found. Molybdenum follows Re in these sediments but Mo is enriched also in those that accumulate under oxidizing conditions. The reported Mo crustal concentrations appear low in comparison to our measured sedimentary values. Gold and Ag are concentrated in hydrothermal deposits and sulfides appear to be involved in the precipitation of these elements. Coastal sediments adjacent to a domestic outfall of Los Angeles, California contain extraordinary high accumulations of anthropogenic Au, Ag and Pt. The study seeks an understanding of the mobilities and sinks of these metals in the marine environment during the major weathering cycle. Further, anthropogenic contributions to their sedimentary concentrations are identified. 相似文献
8.
In terranes subject to complex metamorphic evolution, zircon and monazite U-Pb system can record successive growth and/or resetting episodes. Conventional isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) dating of fractions or single grains from conventionally separated zircon and monazite populations may produce inaccurate ages. A new technique combining textural analysis and ID-TIMS dating on single monazite crystals is proposed. This method is applied directly on thin sections with three successive steps comprising (1) a characterisation of textural relationships using electron microprobe analyses and images, (2) extraction by micro-drilling of selected monazites and (3) U-Pb dating of each extracted grain by ID-TIMS. The potential for this in situ dating technique are tested on Ultra High Temperature (UHT) granulites from North-Central Madagascar. Four distinct events on a single thin section were distinguished. The UHT metamorphism was dated at 2.5 Ga, while two retrogression events were dated at 790 and 500 Ma. Finally, a single crystal shielded in quartz seems to preserve a pre-metamorphic age around 2.7 Ga.Editorial responsibility: J. Hoefs 相似文献
9.
磷灰石微区原位LA-MC-ICP-MS U-Pb同位素定年 总被引：5，自引：0，他引：5
利用激光剥蚀多接收器电感耦合等离子体质谱法(LA-MC-ICP-MS), 建立了磷灰石微区原位U-Pb同位素定年新方法, 本文给出了这一新方法的分析流程, 报道了利用这一新方法对5个磷灰石样品的分析结果, 并应用同位素稀释-热电离质谱法(ID-TIMS)对一些样品定年结果进行了验证。磷灰石工作标样SDG的U-Pb同位素年龄: (1596±15) Ma (MSWD=1.5, n=7, LA-MC-ICP-MS), (1602±13) Ma (MSWD=0.578, n=5, ID-TIMS); 某铁矿石中磷灰石的LA-MC-ICP-MS U-Pb同位素年龄: (125±14) Ma (MSWD=0.68, n=25), (124.2±3.5) Ma (MSWD=1.5, n=37); 新疆阿尔金地区片麻岩中磷灰石的LA-MC-ICP-MS U-Pb同位素年龄: (250.8±3.9) Ma (MSWD=8.6, n=26), (245.4±2.9) Ma (MSWD=2.1, n=39)。 相似文献
10.
11.
A new method integrating high-precision U-Pb geochronology with zircon trace element analysis (U-Pb TIMS-TEA) 总被引：1，自引：0，他引：1
Increased precision in isotope-dilution thermal ionization mass spectrometry (ID-TIMS) U-Pb geochronology has revealed age complexities in zircon populations that require new tools for understanding how the growth of zircon is related to geologic processes. U and Pb are routinely separated from other elements in dated minerals by ion exchange separation prior to TIMS isotope measurement. We develop a method in which trace elements in the exact same volume of zircon are redissolved and analyzed using solution nebulization inductively coupled plasma sector-field mass spectrometry with matrix-matched external liquid calibration. Using <0.5 ml solution, resulting concentrations are between <1 ppt for elements such as Ti, Nb and Ta and tens of ppb for Zr. By analyzing a series of standard solutions, zircons and procedural blanks, we show that accurate measurements are performed on Zr, Hf, Y, Sc, and the HREE while low-concentration elements can be measured accurately to <5 ppt. We performed combined U-Pb ID-TIMS geochronology with trace element analysis (here called U-Pb TIMS-TEA) on zircons from eight volcanic rocks comprising several volcanic systems and one metamorphic sample. Similar to previous in situ trace element analyses, zircon geochemistry is distinct between different samples and records petrogenetic processes such as fractional crystallization, assimilation and/or magma mixing. Unique from in situ analysis, U-Pb TIMS-TEA can trace geochemical evolution in accessory minerals with adequate age precision to resolve magmatic processes in rocks at least 200 million years old. This provides a means to identify auto-, ante- and xenocrystic zircon and lead to more robust age interpretations in ID-TIMS U-Pb geochronology. One suite of Cretaceous andesitic zircons shows correlations in geochemistry and absolute time that record evolution of a magmatic system over ∼250 ka prior to eruption. Future work will combine U-Pb TIMS-TEA with solution isotopic analysis of Nd, Sr and Hf and will be applied to a host of datable minerals such as monazite, sphene, apatite, rutile, xenotime, and baddeleyite. These combined tools will provide access to an improved understanding of a wide range of igneous and metamorphic processes as a function of time. 相似文献
12.
Mayuri Inoue Masato Nohara Takashi Okai Atsushi Suzuki Hodaka Kawahata 《Geostandards and Geoanalytical Research》2004,28(3):411-416
Trace elements in the Geological Survey of Japan carbonate reference materials Coral JCp-1 and Giant Clam JCt-1 were determined by inductively coupled plasma-mass spectrometry after digestion with 2% v/v HNO3 . A standard addition method was adopted in this determination in order to neutralise the Ca matrix effect. In addition, Sc, Y, In and Bi were used as internal standards to control the matrix effect and correct instrumental drift. Of the eighteen elements measured in JCp-1, precisions for fourteen elements, including Cu, Cd and Ba, were better than 10% RSD and concentrations ranged from 0.002 μg g-1 (Cs) to 8.02 μg g-1 (Ba). The concentrations of measured trace elements in JCt-1, except for Cu, were lower than those in JCp-1. Precisions for all elements with concentrations higher than 0.04 μg g-1 in JCt-1 were also better than 10% RSD and concentrations were found to be between 0.001 μg g-1 (Cs) and 4.84 μg g-1 (Ba). The concentrations of more than fifteen trace elements in the aragonite reference materials are reported here for the first time. Both reference materials are suitable for use in geochemical studies of environmental reconstruction based upon biogenic carbonate materials. 相似文献
13.
DETERMINATION OF RARE EARTH ELEMENTS IN SIXTEEN SILICATE REFERENCE SAMPLES BY ICP-MS AFTER TM ADDITION AND ION EXCHANGE SEPARATION 总被引：7，自引：0，他引：7
J.A. BARRAT F. KELLER J. AMOSSÉ R.N. TAYLOR R.W. NESBITT T. HIRATA 《Geostandards and Geoanalytical Research》1996,20(1):133-139
This study reports the results of thirteen rare earth elements (REE) in sixteen geochemical reference samples. The analytical procedure involved dissolution of a whole rock or mineral separate, spiking with Tm, and separation of the REE using a simple ion-exchange chromatography procedure. The resulting REE solutions were analysed by ICP-MS. The results are compared with literature values. The agreement between our data and recommended or ID-TIMS values is very favorable. The precision of the technique is better than 5% (2) for all the REE. 相似文献
14.
Data were obtained for rubidium in six geological reference materials by isotopic dilution thermal ionisation mass spectrometry (ID-TIMS) and wavelength dispersive X-ray fluorescence spectrometry (WD-XRF). The results found by one technique compare very well with the other within the respective analytical uncertainties and are also in good agreement with data from previously published values. The particular case of low Rb determinations in reference sample BIR-1 is discussed. 相似文献
15.
本文以稀土矿床中的常见副矿物氟碳铈矿为研究对象,通过优化实验条件和仪器参数,分别采用激光剥蚀多接收电感耦合等离子体质谱法(LA-MC-ICP-MS)和同位素稀释热电离质谱法(ID-TIMS)对氟碳铈矿样品SAM进行U-Pb定年技术研究,并将此两种方法得到的结果进行对比。LA-MC-ICP-MS得到的U-Pb年龄为(409±18)Ma(N=27,MSWD=4.5),ID-TIMS得到的206Pb/238U U-Pb年龄为(407.8±3.3)Ma(N=3,MSWD=0.029),两种方法得到的U-Pb年龄结果在误差范围内一致。通过比较两种方法的实验流程和结果,总结了各自的优缺点,为氟碳铈矿U-Pb定年方法选择提供了参考依据。 相似文献
16.
T. V. Rundkvist T. B. Bayanova S. A. Sergeev P. V. Pripachkin R. A. Grebnev 《Doklady Earth Sciences》2014,454(1):1-6
The Vurechuaivench layered PGE-bearing pluton (VP) is located in the central part of the Kola Peninsula, at the southeastern contact of the Monchegorsk layered complex with the Paleoproterozoic Imandra-Varzuga rift structure. The VP is composed of gabbronorites with a layered horizon of intercalated gabbronorites and anorthosites, containing sulfide and PGE-bearing mineralization. The U-Pb (ID-TIMS) age of baddeleytte from gabbronorite of the ore zone (sample M-42) was determined on a Finningan MAT-262 (RPQ) seven-channel mass-spectrometer in the Laboratory of Geochronology at the Geological Institute, Kola Scientific Center, Russian Academy of Sciences. Zircons from anorthosites and gabbronorites of the ore zone (samples B-1 and B-2, respectively) were studied on a SHRIMP-II secondary-ionic microprobe in the Center of Isotopic Studies of the Federal State Unitary Enterprise VSEGEI (St. Petersburg). The reliable age of formation of various VP rocks was determined by single grains of accessory baddeleytte and zircon based on additional studies of sample M-42 (2498.2 ± 6.7 Ma) and new studies of samples B-1 and B-2 (2507.9 ± 6.6 and 2504.8.4 Ma). The identical U-Pb ages of anorthosites and gabbronorites from the ore reef indicate that anorthosites are a dependent phase and were formed along with gabbronorites during the intrachamber melt differentiation and crystallization. 相似文献
17.
V. V. Yarmolyuk A. M. Kozlovsky E. B. Salnikova A. V. Travin E. A. Kudryashova 《Doklady Earth Sciences》2017,475(2):872-876
Geochronological studies of rocks from a bimodal high-alkali volcanic–plutonic complex collected in the area of Kharkhorin zone of the Early Mesozoic Mongolian–Transbaikalian igneous province (MTIP) are made. The age of alkali granites from Olziit sum is 211 ± 1 Ma (U–Pb ID-TIMS on zircon) to 209 ± 2 and 217 ± 4 Ma (40Ar/39Ar on alkali amphibole); the age of alkali granite-porphyries from the area of Sant sum is 206 ± 1 Ma (U–Pb ID-TIMS on zircon). These rock series formed syncronously to the analogous magmatism episode in the Northern Gobi and Western Transbaikalian rift zones of the MTIP. The similarity of the age and composition of igneous associations of the MTIP suggests a common mechanism of its formation related to the effect of a mantle plume on the continental lithosphere at the base of the entire igneous zone having a zonal structure. 相似文献
18.
Tesfaye Kebede Urs Klötzli Jan Kosler Torbjörn Skiöld 《International Journal of Earth Sciences》2005,94(3):336-353
New single-grain and within-grain U-Pb zircon ages from the central Tauern Window help sorting out the time dimension among the various Variscan and pre-Variscan basement components that were strongly overprinted by Alpine orogeny. Single-grain isotope dilution (ID-TIMS) U-Pb zircon geochronology of three Basisamphibolit samples yield protolith formation ages of 351±2, 349±1 and 343±1 Ma. Laser ablation ICP-MS and ID-TIMS U-Pb detrital zircon dating of the Biotitporphyroblastenschiefer constrained the maximum time of sedimentation to between 362±6 Ma and 368±17 Ma. Paragneisses from the Zwölferzug yield maximum sedimentation ages from 345±5 Ma (ion microprobe data) to 358±10 Ma. Zircons from gabbroic clasts and detrital zircons from a meta-agglomerate from the Habach Phyllite give an upper intercept age of 536±8 Ma and a near-concordant age of 506±9 Ma, respectively. Hence, apart from the Habach Phyllite, the maximum sedimentation ages of the metasediments investigated range from Upper Devonian to Lower Carboniferous. Consequently, the Basisamphibolit, the Biotitporphyroblastenschiefer, and the paragneisses of the Zwölferzug form parts of the Variscan basement series. The Basisamphibolit (351-343 Ma) is distinct both in space and time of formation from the Zwölferzug garnet amphibolite (c. 486 Ma), which forms part of the pre-Variscan basement. 相似文献
19.
LA-MC-ICP-MS锆石微区原位U-Pb定年技术 总被引：297，自引：33，他引：264
利用激光多接收等离子体质谱(LA-MC-ICP-MS)技术对30～1 065 Ma的系列锆石进行了详细的定年研究.包含离子计数器的多接收系统使得不同质量数的同位素信号可以同时静态接收,并且不同质量数的峰基本上都是平坦的,进而可以获得高精度的数据,均匀锆石颗粒207Pb/206Pb、206Pb/238U、207Pb/235U比值的测试精度(2σ)均为2%左右,对锆石标准的定年精度和准确度在1%(2σ)左右;不同质量数同位素信号的同时静态接收使得剥蚀时间缩短,剥蚀深度变浅,相比LA-ICP-MS方法,提高了激光剥蚀的空间分辨率.对5个锆石标准和2个实际样品的测试表明,206Pb/235U年龄测定误差在1%(2σ)以内,定年结果在误差范围内与前人报道值完全一致,测试精度达到国际同类实验室先进水平. 相似文献
