Determination of Chromium, Nickel, Copper and Zinc in Milligram Samples of Geological Materials Using Isotope Dilution High Resolution Inductively Coupled Plasma-Mass Spectrometry     

Akio Makishima  Katsura Kobayashi  Eizo Nakamura 《Geostandards and Geoanalytical Research》2002,26(1):41-51

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.  相似文献   

The Re-Os Isotopic System: A Review of Analytical Techniques   总被引：4，自引：0，他引：4  

Laurie Reisberg  Thomas Meisel 《Geostandards and Geoanalytical Research》2002,26(3):249-267

Over the past twenty years, successive technological advances have transformed the Re-Os isotopic system into one of the most powerful tools in isotope geochemistry. We present here a brief historical review of these advances and then describe and compare the methods most commonly used today. Our goal is to facilitate the choice of the analytical method best adapted to each specific scientific problem and sample type.  相似文献   

Compositional Heterogeneity in NIST SRM 610-617 Glasses     

Stephen M. Eggins  J. Michael G. Shelley 《Geostandards and Geoanalytical Research》2002,26(3):269-286

Extensive compositional heterogeneity is shown to affect at least twenty four of the doped trace elements in the NIST SRM 610-617 glasses.
Compositional profiling and mapping using laser ablation ICP-MS reveals that all NIST SRM 610-617 wafers examined here contain domains that are significantly depleted in Ag, As, Au, B, Bi, Cd, Cr, Cs, Mo, Pb, Re, (Rh), Sb, Se, Te, Tl and W, and antithetically enriched in Cu (and Pt), with large enrichments in Cd, Fe and Mn also being encountered in some cases. These domains are visible in doubly polished wafers by unaided visual inspection and by transmitted light and schlieren microscopy. They occur in close proximity to the wafer perimeters and also as stretched and complexly folded forms within wafer interiors. The chemical and optical properties of these heterogeneous domains are consistent with those of compositional cords, a phenomenon of glass manufacture where glass bulk composition and physical properties are modified by loss of volatile components from the molten glass surface. The NIST SRM 610-617 glasses may be considered reliable reference materials for microanalysis of only between one half and two thirds of the trace elements with which they were doped, including Be, Mg, Sr, Ba, Sc, Y, REE, V, Zr, Hf, Nb, Ta, Th, U, Ga, In, Sn, Co, Ni and Zn. These elements show no evidence of significant heterogeneity, indicating that the original glass constituents and possible residues remaining in the furnace from preceding glass batch fusions were well homogenised during manufacture.  相似文献   

Determination of Trace Elements in BCS CRM 313/1 (BAS) and NIST SRM 1830 by Inductively Coupled Plasma-Mass Spectrometry and Instrumental Neutron Activation Analysis   总被引：1，自引：0，他引：1  

Belinda Flem  L. Paul Bédard 《Geostandards and Geoanalytical Research》2002,26(3):287-300

In the past, there has been little interest in the trace element characteristics of quartz, and in consequence little activity in the trace element characteristics of reference materials with high silicon content. The main purpose of this paper is to contribute to the characterisation of two international certified reference materials, BCS 313/1 from the Bureau of Analysed Samples, (BAS), UK and SRM 1830 from the National Institute of Standards and Technology (NIST), USA. BCS 313/1 was analysed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS), solution ICP-MS and instrumental neutron activation analysis (INAA). NIST SRM 1830 was analysed by LA-ICP-MS and INAA. Analytical results are reported for more than forty elements, most of them for the first time. For most elements, the results obtained by the different methods agree within 15 % relative. The recent, heightened interest in quartz and in particular the precise determination of trace0element contents in natural quartz samples requires the use of well characterised reference materials such as BCS 313/1 and SRM 1830, to which this study is designed to contribute.  相似文献   

东天山马头滩金矿成矿流体稀土元素特征   总被引：3，自引：1，他引：3  

王志良  毛景文  杨建民  马天林  韩春明 《新疆地质》2002,20(4):367-370

用ICP－MS方法对金矿中磁铁矿－黄铁矿－绿泥石－石英成矿阶段（第Ⅱ成矿阶段）和多金属硫化物阶段（第Ⅲ成矿阶段）石英中的流体包裹体的稀土元素测定，发现第Ⅱ、Ⅲ成矿阶段流体中的REE组成具相同的Eu亏损和相似的右倾斜分布型式。与矿区火山岩和侵入岩的REE组分对比分析，认为成矿流体的REE组成主要继承了火山岩和侵入岩（早期岩浆热液）的Eu亏损和右倾斜特征，但前者的LREE更加富集、分布曲线更加向右陡倾斜，反映与晚期变质水和大气降水的混合作用后，成矿流体中REE组成发生了变化。  相似文献   

Micro-Analytical Zircon and Monazite U-Pb Isotope Dating by Laser Ablation-Inductively Coupled Plasma-Quadrupole Mass Spectrometry     

Keegan E. Alagna  Maurizio Petrelli  Diego Perugini  Giampiero Poli 《Geostandards and Geoanalytical Research》2008,32(1):103-120

In this study we evaluated the capability of a 213 nm laser ablation system coupled to a quadrupole-based ICP-MS in delivering accurate and precise U-Pb ages on zircons and monazites. Four zircon samples ( ca. 50 Ma to ca. 600 Ma) and four monazite samples ( ca. 30 Ma to ca. 1390 Ma) of known ages were analysed utilising laser ablation pits with diameters of 20 μm and 60 μm. Instrument mass bias and laser induced time-dependent elemental fractionation were corrected for by calibration against a matrix-matched reference material. Tera-Wasserburg plots of the calculated U-Pb data were employed to assess, and correct for, common Pb contributions. The results indicated that the LA-ICP-MS technique employed in this study allowed precise and accurate U-Pb isotope dating of zircon and monazite on sample areas 20 μm in diameter. At this spot size, the precisions achieved for single spot ²⁰⁶Pb/²³⁸U ages, were better than 5% (2s) for monazites and zircons with ages down to 30 Ma and 50 Ma, respectively. The precisions reported are comparable to those generally reported in SIMS and LA-MC-ICP-MS U-Pb isotope determinations.  相似文献   

Bulk Chemical Composition of the Ningqiang Carbonaceous Chondrite： An Issue of Classification   总被引：1，自引：0，他引：1       下载免费PDF全文

WANG Guiqin LIN Yangting 《《地质学报》英文版》2007,81(1):141-147

The Ningqiang meteorite is a fall carbonaceous chondrite, containing various Ca-, Al-rich inclusions that usually escaped from secondary events such as high-temperature heating and low- temperature alteration. However, it has not yet been classified into any known chemical group. In order to address this issue, 41 elements of the bulk Ningqiang meteorite were analyzed using inductively coupled plasma mass spectrometry （ICP-MS） and inductively coupled plasma atom emission spectrometry （ICP-AES） in this study. The Allende （CV3） carbonaceous chondrite and the Jilin （H5） ordinary chondrite were also measured as references, and our analyses are consistent with the previous results. Rare earth and other refractory lithophile elements are depleted in Ningqiang relative to both Allende and mean CK chondrites. In addition, the REE pattern of Ningqiang is nearly flat, while that of Allende shows slight enrichment of LREE relative to HREE. Siderophile elements of Ningqiang are close to those of mean CK chondrites, but lower than those of Allende. Our new analyses indicate that Ningqiang cannot be classified into any known group of carbonaceous chondrites, consistent with previous reports.  相似文献   

聚氯酯泡沫塑料富集——ICP-MS测定化探样中微量金的方法   总被引：1，自引：0，他引：1  

李锟 《化工矿产地质》2007,29(4):242-244

试样经王水分解，在10％的王水溶液介质中，加一定量的铁盐，用聚氨酯泡沫塑料吸附富集金，1％硫脲溶液解脱，ICP—MS进行测定。实验结果表明，这种方法精密度高、准确度好，检出限低。其测定范围为0．028—500ng／g。  相似文献   

聚氨酯泡沫塑料富集——ICP-MS测定化探样中微量金的方法   总被引：3，自引：0，他引：3  

李锟 《化工矿产地质》2007,29(4)

试样经王水分解,在10%的王水溶液介质中,加一定量的铁盐,用聚氨酯泡沫塑料吸附富集金,1%硫脲溶液解脱,ICP-MS进行测定。实验结果表明,这种方法精密度高、准确度好,检出限低。其测定范围为0.028～500ng/g。  相似文献   

Zircon Inheritance Reveals Exceptionally Fast Crustal Magma Generation Processes in Central Iberia during the Cambro-Ordovician   总被引：3，自引：0，他引：3  

Bea  F.; Montero  P.; Gonzalez-Lodeiro  F.; Talavera  C. 《Journal of Petrology》2007,48(12):2327-2339

The Variscan basement of the Central Iberian Zone contains abundantCambro-Ordovician calc-alkaline to peraluminous metagranitesand metavolcanic rocks with two notable features: first, theywere apparently produced with no connection to any major tectonicor metamorphic event; second, they have an unusually high zirconinheritance. U–Pb dating combined with cathodoluminescenceimaging reveals that about 70–80%, in some samples nearer100%, of the zircon grains contain inherited pre-magmatic cores,despite the temperature reached by the magmas (about 900°C,calculated using the Ti-in-zircon thermometer) being high enoughto dissolve all the available zircon (from the rock's zirconsaturation temperature, 770–860°C). The fact thatthe dissolution of zircon was so incomplete can only be attributedto the kinetics of heat transfer to and from the magmas. Three-dimensionalmodeling of zircon dissolution behavior in melts with a compositionsimilar to the Iberian Cambro-Ordovician magmas indicates thatthe survival of zircons from the suggested late Pan-Africanprotolith would be possible only if melt production was rapid,specifically less than 10⁴ years, and probably about 2 x 10³years, from the beginning of melting (700°C) to the thermalpeak (900°C). Melt production was followed by fast magmatransfer to upper crustal levels resulting either in surfaceeruption or in the emplacement of small (< 400 m thick) sillsor laccoliths. We suggest that these elevated rates of crustalmelting could only have been caused by intrusion of mantle-derivedmafic magmas, most probably at the base of the crust. This scenariois consistent with a rifting regime in which crust and mantlewere mechanically decoupled; this would explain the scarcityof contemporaneous crustal deformation. Furthermore, fast meltingrates in the lower crust followed by fast melt transportationto the upper crust could also explain the lack of contemporaneousmetamorphism. The speed of the partial melting process resultedin the production of felsic magmas that inherited the geochemicalcharacteristics of their granitoid crustal protolith. This explainsthe apparent contradiction between the calc-alkaline to peraluminousgeochemical characteristics of the magmas and the inferred extensional(i.e. rift-related) tectonic setting. Our model is compatiblewith the hypothesis of fragmentation and dispersal of terranesfrom the northern margin of Gondwana that led to the openingof the Rheic and Galicia–South Brittany oceans and, ultimately,caused the detachment of the Iberian microplate from Armoricaand Gondwana during the early Paleozoic. KEY WORDS: igneous petrology; migmatite; granite; geochemistry; crustal contamination; ICP-MS; laser ablation  相似文献