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1.
Data for as many as 31 elements were determined by instrumental thermal neutron activation analysis for nine European Council for Mutual Economic Assistance (CMEA) rock and ore standards. The National Bureau of Standards plastic clay 98 and the University of Gent fired clay FCG were also analyzed. Synthetic, multielement standards were used and USGS rock standards provided reference samples. Correction factors for uranium fission products on cerium and molybdenum, and also for less commonly encountered spectral interferences, such as those due to the 213 ppm tantalum in granitoid 2B, were evaluated.  相似文献   

2.
A new method for the radiogenic isotope (U–Th–Pa–Ra, Sr, Nd, Hf) analysis of the soluble and insoluble components found within ice cores is presented. Melting experiments with rock standards in the presence of EDTA indicate that carbonates, as well as silicates, can be buffered sufficiently to preclude dissolution. The use of EDTA allows adsorbing species, such as Th and Hf, to remain in solution during melting thus fully separating the dust (insoluble) and sea salt (soluble) components of the ice after filtration. A new elemental separation scheme for low sample masses, less than 5 mg solid material, utilizes 4 primary ion exchange columns and two “clean-up” columns to fully isolate U, Th, Pa, Ra, Sr, Nd, and Hf while maintaining high yields. Elution schemes measured for USGS rock standards and a Chinese loess are presented to provide a comparison for variable matrix compositions. Mass spectrometer techniques were modified to measure small aliquots of the standards, equivalent to the amounts found in ice core samples, 10 ng and less. A MC-ICPMS was employed for the measurement of U, Th, Pa, Ra, and Hf; results of the experiments show that with ion yields up to 1%, rock standards have errors for 234U/238U of 1%, 230Th/232Th of 1.5%, [228Ra] of 9%, and 176Hf/177Hf of 100 ppm. MC-TIMS measurements of Sr and Nd show similar errors for small sample sizes: 87Sr/86Sr of 50 ppm and 143Nd/144Nd of 80 ppm. This new analytical method increases the number of possible tracers measured from a single sample, reducing separation times and sample consumption, as well as providing the addition of a radiometric clock, U-series, to the traditional suite of isotopic tracers, Sr, Nd, and Hf.  相似文献   

3.
劳林娟 《沉积学报》1984,2(4):66-76
锗作为煤中主要伴生元素而加以研究利用,早已为国内外所重视,并为煤炭资源的综合开发利用、提高经济效益,开辟了新的途径。近十多年来,国内在开展全国煤中诸的普查、精查和综合利用的基础上,对其分布规律,富集因素和赋存形态作了某些初步研究,本文仅就煤岩组份与锗的富集问题展开讨论。  相似文献   

4.
Germanium in thirty-four SRM's was determined by hydride generation and ICP-AES after separation of germanium from the concomitant matrix into carbon tetrachloride, and finally back-extraction into water. This procedure permits the determination of 0.1 ppm of germanium in as small as 50 mg sample. The precision and accuracy of the method was established using Basalt BCR-1 as the most precisely determined standard available.  相似文献   

5.
锗是典型的稀散元素,一般伴生于岩石矿物之中,其含量很低,需要有个灵敏的测定方法,目前仍普遍采用苯芴酮萃取比色法。近  相似文献   

6.
The concentrations of bromine and iodine in the USGS marine mud MAG-1, the NRCC marine sediments BCSS-1 and MESS-1, and the NBS estuarine sediment SRM 1646 have been determined by energy-dispersive x-ray fluorescence spectrometry. Matrix and intermediate thickness effects were overcome by standard additions to constant weights of each sample. 3-sigma detection limits are 6 ppm Br and 24 ppm I. There is a need for many more analysts to report their results before "usable values'can be established for these elements in marine sediment reference malterials.  相似文献   

7.
The concentration of molybdenum in 16 U.S. Geological Survey (USGS) standard rocks was determined by a colorimetric procedure using zinc dithiol reagent. The molybdenum content in the rocks was found to range from 0.04 to 37 ppm. The precision of the method is generally better than 10% relative deviation when the molybdenum content is >0.3 ppm. A comparison with values stated in the literature shows that the method is accurate for the range of concentrations determined and the rock types analyzed.  相似文献   

8.
We have developed a new database named GeoReM ( http://georem.mpch-mainz.gwdg.de ) for reference materials and isotopic standards of geochemical and mineralogical interest. Reference samples include rock powders originating from the USGS, GSJ, GIT-IWG, synthetic and natural reference glasses originating from NIST, USGS, MPI-DING, as well as mineral (e.g., 91500 zircon), isotopic (e.g., La Jolla, E&A, NIST SRM 981), river water and seawater reference materials. GeoReM is a relational database, which strongly follows the concept of the three EARTHCHEM databases. It contains published analytical and compilation values (major and trace element concentrations, radiogenic and stable isotope ratios), important metadata about the analytical values, such as uncertainty, uncertainty type, method and laboratory. Sample information and references are also included. Three different ways of interrogating the database are possible: (1) sample names or material types, (2) chemical criteria and (3) bibliography. Some typical applications are described. GeoReM currently (October 2005) contains more than 750 geological reference materials, 6000 individual sets of results and references to 650 publications.  相似文献   

9.
We present a multi-element technique for the simultaneous determination of twelve trace elements in geological materials by combined isotope dilution (ID) sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) following simple sample digestion. In addition, the concentrations of fourteen other trace elements have been obtained using the ID determined elements as internal standards. This method combines the advantages of ID (high precision and accuracy) with those of SF-ICP-MS (multi-element capability, fast sample processing without element separation) and overcomes the most prevailing drawbacks of ICP-MS (matrix effects and drift in sensitivity). Trace element concentration data for BHVO-1 (n = 5) reproduced to within 1–3% RSD with an accuracy of 1–2% relative to respective literature values for ID values and 2–3% for all other values. We have applied this technique to the analysis of seventeen geological reference materials from the USGS, GSJ and IAG. The sample set also included the new USGS reference glasses BCR-2G, BHVO-2G and BIR-1G, as well as the MPI-DING reference glasses KL2-G and ML3B-G, and NIST SRM 612. Most data agreed within 3–4% with respective literature data. The concentration data for the USGS reference glasses agreed in most cases with respective data of the original rock powder within the combined standard uncertainty of the method (2–3%), except the U concentration of BIR-1G, which showed a three times higher concentration compared to BIR-1.  相似文献   

10.
地质样品中Pb同位素分析的高效酸淋洗流程   总被引：1，自引：0，他引：1  
针对地质样品的Pb同位素分析提出了一种简化淋洗法, 以去除样品碎样过程引起的污染.相对前人的淋洗法而言, 简化淋洗法不仅能够得到地质样品中准确的Pb同位素组成, 而且降低了全流程本底并提高了样品处理效率.利用多接收等离子体质谱分析了5个美国地质调查局(USGS) 国际标准参考物质(AGV-1、AGV-2、BHVO-2、BCR-2和G-2) 中的Pb同位素组成, 结合前人的研究, 结果表明第一、二代USGS参考物质在制样过程中均受到不同程度的污染.第一代标准在碎样过程受到的污染比碎样环境造成的普通铅污染严重, 而第二代则相反.淋洗后各种参考物质分别具有相近且均一的Pb同位素组成, 表明对岩石粉末样进行溶样前的淋洗有助于获得样品真实的Pb同位素组成.   相似文献   

11.
Ag, Cd, Ti and Mo are extracted from 3M HCI and 0.03M I as ion associates with trioctylphosphine oxide into MIBK. Measurement of the organic extract by GFAAS enables a determination down to 0.02 ppm of Cd, 0.2 ppm of Ag, Mo and Tl. The procedure has been tested on standard reference rock materials prepared by the GSJ and the USGS.
Ag, Cd, Tl et Mo sont extraits à partir d'une solution de HCI 3M et d'ions I 0.03M associés à une solution de TOPO (Trioctylphosphine oxyde) dans le MIBK. Les dosages dans l'extrait organique par spectrométrie d'absorption atomique avec four graphite permettent une détermination à partir de 0.02 ppm pour Cd et 0.2 ppm pour Ag, Mo et TI. La méthode est testée sur des échantillions de reférence préparés par le GSJ et par I'USGS.  相似文献   

12.
Based on a detailed statistical analysis of chemical data published in the scientific literature, estimates were made of the minimum amounts of recoverable Ge contained within sulphidic zinc ores and coals, given current processing technologies. It is expected that at least 119 kt (～7 kt in zinc ores and ～112 kt in coal) of recoverable germanium exist within proven reserves (at present stage of knowledge) at grades in excess of 100 ppm in sphalerite and 200 ppm in coal, while at least 440 kt (～50 kt in zinc ores and ～390 kt in coal) should become recoverable in the future, being associated to coal reserves at 8–200 ppm Ge and zinc resources containing in excess of 100 ppm Ge in sphalerite. Mississippi Valley Type (MVT) deposits are expected to be the most important hosts of germanium-rich sphalerite, while both brown and hard coals are expected to be equally important as hosts of germanium. The approach taken in this publication shows that reliable minimum estimates for the availability of by-product metals lacking suitable reserve/resource data may be attained by using robust statistical methods and geochemical data published in the scientific literature  相似文献   

13.
Une méthode spectrométrique d'émission atomique à plasma conductif a été appliquée pour l'analyse multiélementaire des échantillons USGS GXR-1 à 6. Cette méthode permet de déterminer simultanément 22 éléments: Ag, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Nb, Ni, P, Pb, Sb, Sn, V, W, Y et Zn, au niveau de traces (ppm) et le Fe en (%). Les résultats obtenus démontrent une bonne concordance avec les valeurs préalablement publiées.  相似文献   

14.
Zusammenfassung Siebzehn internationale Referenzgesteinsproben (USGS: G-1, G-2, W-1, GSP-1, AGV-1, PCC-1, DTS-1, BCR-1; ZGI: GM, BM, TB; CRPG: GR, GA, GH, BR; MRT: T-1; CSS: SY-1) wurden zum Teil naßchemisch auf Haupt- und Nebenbestandteile und emissionsspektrographisch mittels der Kohlenbogen- und Doppelbogenmethode auf 25 Spurenelemente unter Verwendung eines Spektrographen großer Dispersion quantitativ analysiert. Unter Einsatz eines thermochemischen Mischreagens (BaSO4+LaF3) wurden mit der Doppelbogenmethode Nachweisgrenzen von0,1 bis 5 ppm erreicht. Bei Mehrfachanalysen wurde mit dem Kohlebogen ein relativer Fehler von±4 bis±16% erhalten, bei der Doppelbogenmethode von±5 bis±30%. Es wird die Konzentrationsabhängigkeit des relativen Fehlers dargestellt.
Chemical and spectrochemical analysis of international reference samples rocks
Summary Seventeen international reference samples of rocks (USGS: G-1, G-2, W-1, GSP-1, AGV-1, PCC-1, DTS-1, BCR-1; ZGI: GM, TB; CRPG: GR, GA, GH, BR; MRT: T-1; SSC: SY-1) were analysed partly for the main and minor constituents using methods of wet analysis. Twenty-five trace elements were determined with a large optical spectrograph using the carbon and double are methods. The double are methode gives detection limites of 0.1 up to 5 ppm, if thermochemical reagents (BaSO4+LaF3) are applicated. The carbon arc method shows a relative error of±4 up to±16% depending mostly on the concentration of the trace element, during the double arc methode results a relative error of±5 up to±30%.

Mit 5 Abbildungen  相似文献   

15.
After acid digestion, gold is extracted with MIBK and determinated by flameless atomic absorption spectrometry. The results for six USGS reference samples and fourteen French geochemical standards are presented and discussed. The agreement with working values for these standards is in the range of pm 5%.  相似文献   

16.
Elemental composition data on eight older (AGV-1, BCR-1, DTS-1, G-1, G-2, GSP-1, PCC-1 and W-1) and three newer (BIR-1, DNC-1 and W-2) USGS rock standards have been collected from institutional reports and journal articles from 1972–1981. This collection was combined with data from previous compilations and "consensus values" for up to 79 elements determined by comparing overall means, medians, and individual means based on analytical techniques.  相似文献   

17.
Routine XRF determination of 19 trace elements in 23 international standards using the method of Leake et al is examined. Agreement of results for 15 well-established international reference samples is generally good, showing that this method gives comparable results to other techniques. New trace element data using this method are presented for the 8 USGS III standards.  相似文献   

18.
Sr isotopic compositions and Rb / Sr ratios of three USGS glasses (BHVO-2G, BIR-1G, BCR-2G) are identical to those of the original USGS reference materials. NKT-1G and TB-1G give values of 0.70351 and 0.70558, respectively. Pb isotopic ratios were measured by the standard-sample bracketing technique on an MC-ICP-MS, which give results that are comparable in accuracy and reproducibility to double spike analyses. However, assessment of the reproducibility of the technique is hampered by inhomogeneous contamination of all USGS reference materials analysed. This contamination is likely to be the reason why the USGS glasses do not all have the same Pb isotopic composition as their unfused originals. Powdered glasses, distributed for characterisation of the glasses by bulk analytical techniques, do not all have the same Pb isotopic compositions as the solid glass material, and can therefore not be used for this purpose.  相似文献   

19.
《International Geology Review》2012,54(10):1212-1238
The Barrigão re-mobilized copper vein deposit, Iberian Pyrite Belt, southern Portugal, is located about 60 km south of Beja and 10 km southeast of the Neves Corvo ore deposit, in Alentejo Province. The deposit is structurally associated with a NE–SW striking fault zone inferred to have developed during late Variscan deformation. The copper ore itself is a breccia-type ore, characterized by up to four ore-forming stages, with the late stages showing evidence of fluid-driven element re-mobilization. The ore is dominated by chalcopyrite?+?tennantite-tetrahedrite, with minor arsenopyrite, pyrite, and löllingite. The supergene paragenesis is composed mainly of bornite, covellite, and digenite. Whole-rock analyses show anomalous tin and germanium contents, with averages of 320 and 61 ppm, respectively. Electron microprobe analysis of Barrigão ores revealed the germanium and tin to be restricted to chalcopyrite, which underwent late-stage hydrothermal fluid overprint along distinct vein-like zones. The measured zonal enrichment of tin and germanium is related to limited element re-mobilization associated with mineral replacement, which resulted in distinctive mineral disequilibrium. Fluid-driven element zoning affected chalcopyrite and tennantite coevally. The average contents of germanium and tin in chalcopyrite are of 0.19 and 0.55 wt.%, respectively, as confirmed through additional micro-proton-induced X-ray emission (micro-PIXE) analysis. The distribution of tin and germanium in chalcopyrite correlates strongly with iron. Tin and germanium covary. Minute sub-microscopic inclusions of an unknown Cu–Sn–Ge sulphide phase have been detected in chalcopyrite and in small vugs therein. These inclusions hint at a stanniferous sulphide as the most possible host for tin and germanium in chalcopyrite, although the idea of limited incorporation of these two elements through element substitution cannot be completely excluded.  相似文献   

20.
Four mafic USGS rock standards (BHVO-1, BIR-1, DNC-1, BCR-1) were analyzed at three sample sizes (1, 5, and 10 g) for gold by neutron activation analysis subsequent to fire-assay concentration. The results indicate that large samples, in the order of 10 g, are required to produce consistent results, although analyses of variance indicate that sample sizes of 5 g may be used effectively. The analysis of 1 g samples resulted in a large range of values and high standard deviations. BCR-1 was found to be the most homogeneous of the four standards for gold, followed in decreasing order by BIR-1, DNC-1, and BHVO-1. Data for Ir in BIR-1 and DNC-1 are also presented.  相似文献   

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