bluuebunny/crossref_metadata_2025 huggingface dataset:
SIPVADE: A New Computer Programme with Seventeen Statistical Tests for Outlier Detection in Evaluation of International Geochemical Reference Materials and its Application to Whin Sill Dolerite WS‐E from England and Soil‐5 from Peru
Authors: Verma* Surendra P. , Orduña‐Galván Leonides Javier , Guevara Mima
Published: May 2007

A new computer programme was written in programming language TURBOC, which enables us to apply a procedure involving seventeen statistical tests (a total of sixty five single or multiple outlier versions of these tests) for outlier detection in univariate sample at a high confidence level of 99% (significance level α= 0.01). The outlying observations should be evaluated first for technical reasons and then rejected manually from the data base until no more outliers are detected and the final statistical parameters are computed from the remaining data. This programme has been used successfully to process two reference material data bases: WS‐E from England and Soil‐5 from Peru. The final mean values for WS‐E are more reliable (characterized by smaller standard deviations and narrower confidence limits) than those obtained earlier using a different statistical approach. The application of a large number of statistical tests to Soil‐5 also resulted in smaller standard deviation values for most elements than the method involving a limited number of such tests. For WS‐E, some laboratories seem to have produced multiple data that were detected as statistical outliers. A close analysis of the distribution of outliers as a function of laboratory, country and analytical method leads to a technical justification for these outlying observations, probably in terms of inadequate QA/QC practices. Use of geochemical criteria indicates that the new mean values in WS‐E might be closer to the “true” concentrations. This procedure of outlier detection and elimination is therefore recommended in the study of the existing RM.
A Preliminary Study on the Preparation of Four Pacific Ocean Polymetallic Nodule and Sediment Reference Materials: GSPN‐2, GSPN‐3, GSMS‐2 and GSMS‐3
Authors: Wang Yimin , Luo Daihong , Gao Yushu , Song Haowei , Li Jiaxi , Chen Weiyue , Teng Yunye , Zhou Shiguang
Published: May 2007

The research project for the preparation of two polymetallic nodule (GSPN‐2, GSPN‐3) and two marine sediment (GSMS‐2, GSMS‐3) reference materials was completed in 1996. The samples were collected from the Eastern and Central Pacific Ocean and prepared to less than 74 μm fine powder. The homogeneity of the materials was tested by X‐ray fluorescence spectrometry. The relative standard deviations (RSD %) of measurements of selected elements in samples taken from thirty bottles selected at random were less than 0.5%. Thirty four laboratories worldwide participated in the collaborative analysis programme. The number of elements or constituents analysed was seventy nine for nodules and eighty one for sediments. Among those, sixty three elements were certified in each sample. The sum of major elements or components is 99.7% for GSPN‐2, 99.5% for GSPN‐3, 99.8% for GSMS‐2 and 99.8% for GSMS‐3.
Determination of Zirconium, Niobium, Hafnium and Tantalum at ng g‐1 Levels in Geological Materials by Direct Nebulisation of Sample HF Solution into FI‐ICP‐MS
Authors: Makishima Akio , Nakamura Eizo , Nakano Toshio
Published: May 2007

We have developed a rapid and accurate method to determine Zr, Nb, Hf and Ta (denoted as HFSE) in geological samples by inductively coupled plasma‐mass spectrometry fitted with a flow injection system (FI‐ICP‐MS). The method involves sample decomposition by HF followed by HF dissolution of HFSE coprecipitated with insoluble M and Ca fluoride residues formed during the initial HF attack. This HF solution was directly nebulized into an ICP mass spectrometer. An external calibration curve method and an isotope dilution method (ID) were applied for the determination of Nb and Ta, and of Zr and Hf, respectively. Recovery yields of HFSE were > 96% for peridotite, basalt and andesite compositions, apart from Zr and Hf for peridotite (> 85%). No matrix effects for either signal intensities of HFSE or isotope ratios of Zr and Hf were observed in basalt, andesite and peridotite solutions down to a dilution factor of 100. Detection limits in silicate rocks were 40, 2, 1 and 0.1 ng g‐1 for Zr, Nb, Hf and Ta, respectively. This technique required only 0.1 ml of sample solution, and thus is suitable for analysing small and/or precious samples such as meteorites, mantle peridotites and their mineral separates. We also present newly determined data for the Zr, Nb, Hf and Ta concentrations in USGS silicate reference materials DTS‐1, PCC‐1, BCR‐1, BHVO‐1 and AGV‐1, GSJ reference materials JB‐1, ‐2, ‐3, JA‐1, ‐2 and ‐3, and the Smithsonian reference Allende powder.
Determination of Forty Four Major and Trace Elements in GPMA Magmatic Rock Reference Materials using X‐ray Fluorescence Spectrometry (XRF) and Instrumental Neutron Activation Analysis (INAA)
Authors: Maghraoui Mohammed El , Joron Jean‐Louis , Etoubleau Joël , Cambon Pierre , Treuil Michel
Published: May 2007

The “GPMA” samples distributed by the Research Institute of Applied Physics (Irkutsk) for collaborative study were analysed for forty four elements by X‐ray fluorescence spectrometry (XRF) and instrumental neutron activation analysis (INAA). Analytical data obtained are presented along with a description of the analytical procedures for the two methods. For elements analysed by both techniques, generally favourable agreement is observed with, however, some exceptions. Small systematic discrepancies are noted for Co, Ba which are likely to be caused by small differences in the calibration response of the two techniques. Routinely in INAA, GS‐N was used as the primary calibration standard while reference materials BE‐N, AC‐E and GXR‐4 were analysed concurrently to assess the traceability of results. Mean values obtained for these reference materials during the last 15 0 runs show good agreement between measured and accepted values.
New Reference Material of Dunite Rock, NGRI‐UMR: Preparation and Evaluation
Authors: Govil Pradip K. , Narayana B.L.
Published: May 2007

A dunite reference material has been prepared as part of the reference materials programme at the National Geophysical Research Institute, Hyderabad, India. The scarcity of reference materials for undertaking the chemical analysis of ultramafic rocks for major and trace elements justified the preparation of such a rock reference material. A 300 kg sample of starting material was collected from an active quarry near the town of Salem in Tamil Nadu, southern India. The sample was homogenized and an invitation for round robin participation was published in Geostandards Newsletter (October 1995). A total of twenty seven international laboratories participated in the study, providing information on the total element concentration of major, minor, trace and rare earth elements. Following data compilation, outlier rejection, and statistical analysis, proposed and indicative total element concentrations are reported for twenty four elements.
GeoPT3. International Proficiency Test for Analytical Geochemistry Laboratories ‐ Report on Round 3
Authors: Thompson Michael , Potts Philip J. , Kane Jean S. , Chappell Bruce W.
Published: May 2007

Results from seventy two laboratories participating in GeoPT3, round three of the international proficiency testing programme for analytical geochemistry laboratories, are presented. The report includes analytical results contributed by participating laboratories, together with the z‐scores derived from these results using appropriate fitness for purpose criteria. These data are available for use as part of the laboratories’ quality control procedures to assess the reliability of analysed results.
Determination of Molybdenum, Antimony and Tungsten at sub μg g−1Levels in Geological Materials by ID‐FI‐ICP‐MS
Authors: Makishima Akio , Nakamura Eizo
Published: May 2007

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−1level. 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.
Determination of Zr and Hf in a Flux‐Free Fusion of Whole Rock Samples using Laser Ablation Inductively Coupled Plasma‐Mass Spectrometry (LA‐ICP‐MS) with Isotope Dilution Calibration
Authors: Reid Joy E. , Horn Ingo , Longerich Henry P. , Forsythe Lance , Jenner George A.
Published: May 2007

Isotope dilution calibration has been applied to the determination of Zr and Hf in whole rocks by laser ablation (LA)‐ICP‐MS. Enriched isotopes were added during the preparation of flux‐free, synthetic whole rock glasses and homogenised through a combination of grinding and fusion. This method avoids problems, such as solution instability and the chemical resistance of minerals such as zircon, inherent in acid digestion sample preparation. The use of isotope dilution removes the need for external calibration using certified reference material glasses such as NIST SRM 612 for which certified Zr and Hf values are not available. The precision of Zr and Hf determinations were found to be < 1% and 3.5% respectively, limited by Poisson counting statistics which contributed to 50% of the final precision of analysis. Measured values correlate closely with compiled literature values.
NIST SRM 610, 611 and SRM 612, 613 Multi‐Element Glasses: Constraints from Element Abundance Ratios Measured by Microprobe Techniques
Authors: Hinton Richard W.
Published: May 2007

The SRM 600 series of glasses, SRM 611 to SRM 619, which nominally contain 500 (SRM 610, 611), 50 (SRM 612, 613), 1 (SRM 614, 615) and 0.02 (SRM 616, 617) μg g−1 of sixty one elements are now being extensively used as microprobe standards. Recent compilations of the trace element concentrations, which include many new multi‐element bulk analyses, do not all give the same value within the stated uncertainty; this observation appears to raise questions about the degree of homogeneity on a microscale reported from probe measurements. The ion microprobe cannot give absolute concentrations, but can accurately measure the abundance ratios between glasses of similar major element chemistry. Recent and new probe measurements show that, although the absolute concentrations are significantly lower than the nominal values, the average dilution factors are 12 : 1 : 0.02 : 0.0004 and close to weighed amounts. The consistency between the ratios of random samples of glasses (SRM 610/SRM 612 and SRM 611/SRM 613) strongly supports a high degree of homogeneity on all scales. The measured abundance ratios between two glasses can, therefore, act as a useful check on bulk measurement accuracy. A clear correlation in the SRM 610, 611/SRM 612, 613 ratios measured by ion probe and SRM 612 trace concentrations measured by bulk techniques demonstrates that SRM 610, 611 has a much more uniform trace content than SRM 612, 613.
An Interpretation of ISO Guidelines for the Certification of Geological Reference Materials
Authors: Kane Jean S. , Potts Philip J.
Published: May 2007

Recommendations for the certification of reference materials, as published by the International Organisation for Standardisation (ISO), are reviewed and proposals made as to how they can be adapted for the certification of new geological reference materials. Whilst acknowledging the important contribution made by the large number of existing matrix‐matched geological reference materials, it is recommended that future characterisation programmes should follow the ISO guidelines for certification, not the least so that laboratories can readily use the resultant samples to establish the traceability of geoanalytical results.
Additional Provisional Elemental Values for LKSD‐1, LKSD‐2, LKSD‐3, LKSD‐4, STSD‐1, STSD‐2, STSD‐3 and STSD‐4
Authors: Lynch John
Published: May 2007

Provisional values related to element concentration derived from partial extractions as well as some additional total concentration data are reported for eight CCRMP sediment reference materials. These values are intended to supplement previously published data for these samples. The partial extractions for which data are reported include dilute HNO3 ‐ dilute HCl, concentrated HNO3 ‐concentrated HCl and concentrated HNO3 ‐concentrated HClO4.
Fractional Determination of Gold in Twenty Six Geological Reference Materials by Sequential Extraction with Graphite Furnace Atomic Absorption Spectrometry
Authors: Terashima Shigeru , Taniguchi Masahiro
Published: May 2007

A method is described to estimate the chemical form of gold (Au) in a variety of geological reference samples, combining a sequential extraction scheme with graphite furnace atomic absorption spectrometry, after extraction of Au as iodide or chloride with methyl isobutyl ketone. The fractions dissolved by sequential extraction are empirically defined as the exchangeable, amorphous, metallic, aqua regia‐soluble and residual fractions. The amounts of Au in the amorphous fraction have been derived mainly from oxide or amorphous phases, and the chemical forms of Au are considered to be mostly amorphous and partly metallic. The metallic fraction of Au is likely to exist as submicroscopic grains of native metal which are relatively free from the rock‐forming minerals, whereas the aqua regia‐soluble or residual fraction of Au may be bound more intimately perhaps as inclusions or solid solutions of either native metal or electrum in most cases. Satisfactory agreement was observed between the sum of the Au values from exchangeable to residual fractions and the reported total Au values, except for a few samples which contained a large amount of reducing materials. Analytical results of Au for twenty six geological reference materials are tabulated, and geochemical and mineralogical features are discussed.
A Routine Method for Oxide and Hydroxide Interference Corrections in ICP‐MS Chemical Analysis of Environmental and Geological Samples
Authors: Aries Sébastien , Valladon Michel , Polvé Mireille , Dupré Bernard
Published: May 2007

Inductively coupled plasma‐mass spectrometry has revolutionized the field of multi‐elemental analysis because of its high sensitivity and speed of analysis. However, problems with polyatomic ion interferences during routine analysis can give rise to inaccuracies. We propose a method that systematically corrects for oxide and hydroxide interferences in routine analysis, for a wide range of materials. Oxide and hydroxide production for a specified element is calculated from measurements on each sample, as levels may depend on sample composition and may also vary with time. We show that oxide and hydroxide interferences can then be calculated for other elements, by reference to a set of oxide and hydroxide ratios measured on standard solutions. Validity of correction is controlled by internal tests involving two isotopes of one element with respect to experimental errors. The limits and validity of this approach are demonstrated with the analysis of selected reference materials.
Pb‐Isotope Analyses of USGS Reference Materials
Authors: Woodhead Jon D. , Hergt Janet M.
Published: May 2007

Conventional corrections for thermal ionisation mass spectrometer (TIMS) induced Pb‐isotopic fractionation often result in a loss of accuracy because the commonly employed pure Pb reference materials (NIST SRM 981, 982) frequently exhibit markedly different fractionation behaviour to real geological samples. As a result, these SRMs are inappropriate for comparison and/or correction of inter‐operator/ laboratory biases. A matrix‐matched reference material would be preferable but, as yet, no systematic study has approached this problem. Here we present high quality Pb‐isotope ratio determinations, obtained using a double spike procedure, for six USGS reference materials in an attempt to address this deficiency. Our data suggest that most of these rocks could be used as isotopic reference materials comparable, in terms of uncertainty, to the NIST SRMs. However, significant differences in isotopic composition exist between first (e.g. BCR‐1) and second (e.g. BCR‐2) generation samples. The cause of these differences remains unclear but has significant implications for their use as trace element reference materials.
Determination of Trace Elements in the Quartz Reference Material UNS‐SpS and in Natural Quartz Samples by ICP‐MS
Authors: Monecke Thomas , Bombach Gisela , Klemm Werner , Kempe Ulf , Götze Jens , Wolf Dieter
Published: May 2007

A procedure for the digestion and analysis of quartz samples was developed to measure trace element concentrations in natural quartz. The certified glass sand reference material UNS‐SpS was chosen to assess the precision, accuracy and detection limit of the analytical method. Quartz was digested with HF/HNO3 in a closed glassy carbon vessel and analysed by means of quadrupole ICP‐MS with external calibration. Analyte concentrations of the sand UNS‐SpS were compared with certified and other values from the literature. The abundances of a number of elements (Pr, Gd, Ho and Er) in the reference material are reported here for the first time. The procedure was then applied to three quartz samples from different geological settings to show that trace element data by ICP‐MS can distinguish the origin of the sample.
The Preparation and Preliminary Characterisation of Eight Geological MPI‐DING Reference Glasses for In‐Situ Microanalysis
Authors: Jochum Klaus Peter , Dingwell Donald B. , Rocholl Alexander , Stoll Brigitte , Hofmann Albrecht W. , Becker S. , Besmehn A. , Bessette D. , Dietze H.‐J. , Dulski P. , Erzinger J. , Hellebrand E. , Hoppe P. , Horn I. , Janssens K. , Jenner G.A. , Klein M. , McDonough W.F. , Maetz M. , Mezger K. , Müker C. , Nikogosian I.K. , Pickhardt C. , Raczek I. , Rhede D. , Seufert H.M. , Simakin S.G. , Sobolev A.V. , Spettel B. , Straub S. , Vincze L. , Wallianos A. , Weckwerth G. , Weyer S. , Wolf D. , Zimmer M.
Published: May 2007

Eight silicate glasses were prepared by directly fusing and stirring 50‐100 g each of basalt, andesite, komatiite, peridotite, rhyolite, and quartz‐diorite. These are referred to as MPI‐DING glasses and were made for the purpose of providing reference materials for geochemical, in‐situ microanalytical work. Results from various analytical techniques indicate that individual glass fragments are well homogenised with respect to major and trace elements at the μm to mm scale. Heterogeneities due to quench crystallisation of olivine have been observed in small and limited areas of the two komatiitic glasses. In order to obtain concentration values for as many elements as possible, the glasses were analysed by a variety of bulk and microanalytical methods in a number of laboratories. The analytical uncertainties of most elements are estimated to be between 1% and 10%. From the analytical data, preliminary reference values for more than sixty elements were calculated. The analytical uncertainties of most elements are estimated to be between 1% and 10%.
Multi‐Wavelength Synchrotron Radiation XRF Determination of U and Th in Sedimentary Cores from Lake Baikal
Authors: Phedorin Michael A. , Goldberg Evgeny L. , Bobrov Vladislav A. , Khlystov Oleg M. , Grachev Michael A.
Published: May 2007

A new technique for the determination of uranium and thorium in lacustrine sediments is based on non‐destructive synchrotron radiation X‐ray fluorescence analysis (SR‐XRF) of sediment samples using monochromatic beams of different energies as excitation sources, with the recording and subsequent iterative processing of the X‐ray fluorescence spectra. The technique has a multielement capability and enables fast, simultaneous analysis of a few tens of elements. The proposed SR‐XRF technique was tested against INAA and ICP‐MS methods and showed a number of advantages with a generally good correlation of results by the three methods. Uranium and Th profiles have been measured at a time resolution of 2 kyr in a drill core (BDP‐96) from Lake Baikal bottom sediments deposited between 780 and 40 kyr B P. During this time span, peaks in the U and U/Th concentration marked warm climates. Oscillations of U and U/Th in Baikal bottom sediments during the Brunhes chron reflect climate‐induced global change in the volume of polar ice, controlled by long‐term cyclicity of the Earths orbital parameters. The response of these warm periods is similar to that observed earlier in shorter cores that span the two last interglacials (220‐0 kyr BP).
New ID‐TIMS, ICP‐MS and SIMS Data on the Trace Element Composition and Homogeneity of NIST Certified Reference Material SRM 610‐611
Authors: Rocholl Alexander , Dulski Peter , Raczek Ingrid
Published: May 2007

We present new concentration data for twenty four lithophile trace elements in NIST certified reference material glasses SRM 610‐SRM 611 in support of their use in microanalytical techniques. The data were obtained by solution ICP‐MS and isotope dilution TIMS analysis of two different sample wafers. An overall assessment of these new results, also taking into account ion probe studies that have been published in the literature, shows that these wafers can be considered to be homogeneous. Therefore, individually analysed wafers are believed to be representative of the entire batch of the SRM 610‐611 glasses. Possible exceptions are the alkali metals (and a few volatile or non‐lithophile trace elements). The analysed concentrations range between 370 μg g−1 (Cs) and 500 μg g−1 (Sr) and agree well with published values. On the basis of our new data and data recently published in the literature we propose “preferred average” values for the elements studied. These values are, within a few percent, identical to those proposed by other workers.
A Protocol for the Determination of the Rare Earth Elements at Picomole Level in Rocks by ICP‐MS: Results on Geological Reference Materials USGS PCC‐1 and DTS‐1
Authors: Olive Valerie , Ellam Rob M. , Wilson Lyn
Published: May 2007

Rare earth element analyses are widely used in geology, environmental science and archaeology. Over the past decade inductively coupled plasma‐mass spectrometry has become an important source of rare earth data on geological material. However, ICP‐MS analysis of rock samples without pre‐concentration can be problematic because of complex sample matrices that can generate significant molecular isobaric interferences on rare earth peaks and which need to be corrected. Such problems are exacerbated for ultramafic rocks because the low levels of rare earth elements demand more concentrated solutions in order to maintain signals above background levels. These high solid loads result in intra‐run changes in instrument sensitivity which need to be monitored. Pre‐concentration chemistries have been developed in order to avoid high solid loads but these are time‐consuming and must offer quantitative recoveries or use a yield tracer. Here, we describe an alternative method for rare earth element analysis by ICP‐MS, which involves no pre‐concentration and is, therefore, able to deliver data rapidly. Our approach is to apply an external correction procedure, based on the analysis of a reference material closely matched in composition to the unknown samples, which allows correction for both interferences and variations in instrument sensitivity. Testing this method, we obtained accurate rare earth element results for basaltic rocks with a precision of about 2% (1s). We demonstrate that the method is also applicable to ultramafic rocks with abundances at ultra‐trace (ng g−1) level and present data for twelve separate dissolutions of the peridotite USGS PCC‐1 and four separate dissolutions of the dunite DTS‐1 reference materials. The repeatability of the data is between 3% and 9% (1s).
Strontium, Neodymium and Lead Isotope Analyses of NIST Glass Certified Reference Materials: SRM 610, 612, 614
Authors: Woodhead Jon D. , Hergt Janet M.
Published: May 2007

The NIST glass certified reference materials, SRM 610‐617, have been widely adopted by the geological community as calibration samples for a variety of in situ trace element analytical techniques. There is now an urgent requirement for similar reference materials for in situ isotopic analytical techniques. We have analysed SRM 610, 612 and 614 for their Pb, Sr and Nd isotopic compositions using thermal ionisation mass spectrometry. Large differences in isotopic composition were observed between each CRM, suggesting a significant trace element content in the initial starting material (base glass). As a result, isotopic compositions for one CRM cannot be extrapolated to another, and each must be calibrated for use independently. We present the first compilation of working values for these glasses.
A New Model for Sampling of Particulate Materials and Determination of the Minimum Sample Size
Authors: Geelhoed Bas , Glass Hylke‐Jan
Published: May 2007

A novel model for the sampling of particulate materials is presented. In this model, the sampling error in concentration estimates due to the random packing of the particles in the batch is distributed according to the recently developed mass‐based multinomial distribution. Using the model and assuming ideal sampling, a scheme to estimate the minimum sample mass is verified with computer simulation.
Comparison of UV and IR Laser Ablation ICP‐MS on Silicate Reference Materials and Implementation of Normalisation Factors for Quantitative Measurements
Authors: Motelica‐Heino Mikael , Donard Olivier F.X.
Published: May 2007

Direct analysis of geological reference materials was performed by LA‐ICP‐MS using two Nd:YAG laser systems operating at 266 nm and 1064 nm. The aim of this work was to compare UV and IR laser ablation and to assess the potential of the technique for the quantitative bulk analysis of rocks, sediments and soils. The laser sampling process was investigated and the analytical performance of both systems was compared. The influence of the laser operating conditions and the nature of the matrix on ICP‐MS response factors calculated for major, minor and trace elements was evaluated. Under consistent laser settings, the response factors appeared to be matrix dependent. For a given matrix, the response factors were also significantly different for the two lasers. Normalisation with a single matrix element was effective only for matrices with similar mineralogy. When operating at 266 nm instead of 1064 nm, matrix effects could be reduced but not overcome. However, variations of the response factors between the different matrices appeared to be similar within distinct groups of elements, reflecting geochemical associations. When using multiple internal standards, matrix effects but also effects of the laser wavelength, could be fully compensated.
Application of Laser Ablation ICP‐MS to U‐Th‐Pb Dating of Monazite
Authors: Kosler Jan , Tubrett Mike N. , Sylvester Paul J.
Published: May 2007

Recent advances in laser ablation ICP‐MS techniques allow accurate U‐Th‐Pb age dating of monazites that are as young as several tens of million years to a precision better than 2%. Accuracy of the age determinations has been improved by true real‐time mass bias correction via nebulisation of a solution containing enriched 233U and natural Tl isotopes. The Tl‐U tracer solution eliminates possible effects of variable sample matrices on the precision and accuracy of measured isotopic ratios. Mass bias corrections based on measured 205Tl/233U ratios in the tracer solution allow direct measurement of 235U in monazite. Combined with high‐sensitivity laser ablation ICP‐MS measurements, direct measurement of 235U particularly improves the precision of U‐Pb dating of young monazites. Correction for laser‐induced Pb/U and Pb/Th elemental fractionation is based on a mathematical treatment of time resolved count‐rate data that is independent of laser ablation characteristics, does not require external standardisation and allows variable laser pit size or raster patterns for each measurement. The new procedures make the LA ICP‐MS technique more flexible for in situ U‐Th‐Pb analysis.
Boron Isotopic Analysis of Proposed Borosilicate Mineral Reference Samples
Authors: Leeman William P. , Tonarini Sonia
Published: May 2007

This brief contribution presents new boron isotopic data for a set of proposed borosilicate reference minerals, most of which are described in the companion paper by Dyar et al.2001. The results for a variety of minerals (tourmalines, danburite, prismatine, serendibite, ferroaxinite and a Li mica) show that it is generally possible to reproduce the 11 B/10 B ratio within ± 0.5 per mil with replicate chemistry and mass spectrometry over long time spans. Because the accuracy of boron isotopic analysis is commonly determined by reference to secondary standards, it is suggested that some of the samples used in this study be adopted for interlaboratory comparisons and for quality control on boron isotopic analyses produced by a variety of analytical methods.
Reference Minerals for the Microanalysis of Light Elements
Authors: Dyar M. Darby , Wiedenbeck Michael , Robertson David , Cross Laura R. , Delaney Jeremy S. , Ferguson Kurt , Francis Carl A. , Grew Edward S. , Guidotti Charles V. , Hervig Richard L. , Hughes John M. , Husler John , Leeman William , McGuire Anne V. , Rhede Dieter , Rothe Heike , Paul Rick L. , Richards Ian , Yates Martin
Published: May 2007

The quantitative determination of light element concentrations in geological specimens represents a major analytical challenge as the electron probe is generally not suited to this task. With the development of new in situ analytical techniques, and in particular the increasing use of secondary ion mass spectrometry, the routine determination of Li, Be and B contents has become a realistic goal. However, a major obstacle to the development of this research field is the critical dependence of SIMS on the availability of well characterized, homogeneous reference materials that are closely matched in matrix (composition and structure) to the sample being studied. Here we report the first results from a suite of large, gem crystals which cover a broad spectrum of minerals in which light elements are major constituents. We have characterized these materials using both in situ and wet chemical techniques. The samples described here are intended for distribution to geochemical laboratories active in the study of light elements. Further work is needed before reference values for these materials can be finalized, but the availability of this suite of materials represents a major step toward the routine analysis of the light element contents of geological specimens.
A Compilation of Silicon and Thirty One Trace Elements Measured in the Natural River Water Reference Material SLRS‐4 (NRC‐CNRC)
Authors: Yeghicheyan Delphine , Carignan Jean , Valladon Michel , Le Coz Martine Bouhnik , Cornec Florence Le , Castrec‐Rouelle Maryse , Robert Michel , Aquilina Luc , Aubry Emmanuel , Churlaud Carine , Dia Aline , Deberdt Samuel , Dupré Bernard , Freydier Rémi , Gruau Gérard , Hénin Odile , de Kersabiec Anne‐Marie , Macé Joël , Marin Luc , Morin Nicole , Petitjean Patrice , Serrat Elodie
Published: May 2007

The natural river water certified reference material SLRS‐4 (NRC‐CNRC, National Research Council‐Conseil National de Recherches Canada) has been routinely analysed for major and trace elements by six French laboratories. Most measurements were made using inductively coupled plasma‐mass spectrometry. For silicon and thirty one trace elements (rare earth elements, Ag, B, Br, Cs, Ga, Ge, Li, P, Pd, Rb, Se, Th, Ti, Tl, W, Y and Zr), no certified values are assigned by NRC‐CNRC. We propose some compilation values and related uncertainties according to the results obtained by the different laboratories.
Determination of Gold, Silver and Platinum‐Group Elements in Geochemical Reference Materials by Direct Atomic Emission Spectral Analysis Using a Multichannel Analyser Recording Device
Authors: Zayakina Svetlana B. , Anoshin Gennady N.
Published: May 2007

A procedure for the analysis of geochemical samples has been developed based on direct atomic‐emission spectrometry for the determination of silver, gold and the platinum‐group elements. Instrumentation comprised a DC arc emission two‐jet plasmatron coupled to a diffraction spectrograph and multichannel analyser for recording emission spectra. Spectrum analysis used a comprehensive library of spectral lines for practically all elements excited using this emission source. The software programme for the automatic registration of spectra and subsequent data processing are described and results presented for a number of geochemical reference materials.
Evaporation and Sublimation of Boric Acid: Application for Boron Purification from Organic Rich Solutions
Authors: Gaillardet Jérôme , Lemarchand Damien , Göpel Christa , Manhès Gérard
Published: May 2007

We report in this paper a series of experiments whose purpose is to test the long held idea of boron volatility when neutral to acidic solutions containing traces of boron are evaporated. Boron recoveries have been measured precisely by isotopic dilution and boron isotopic ratios have also been determined. Most of the evaporations have been conducted at 60‐65 °C. It was found that no loss of boric acid occurs when c. 1 μg of B is evaporated in water, HCl, HF and acetone solutions. At the same time, we did not observe any associated B isotopic fractionation. In contrast to previous studies on B volatilisation, it was not found necessary to use mannitol to prevent B losses during the evaporation of acidic solutions. Important losses of boron were observed from solutions of methanol, ethanol and organic‐rich natural solutions. In the presence of methanol and ethanol, a volatile methyl (or ethyl) borate is likely to be formed. In contrast to these studies, we show that boron is highly volatile when the dried residues of an evaporation are heated further. The sublimation of boron that then occurs can be moderated by the use of mannitol, but a slight increase of the temperature allows B volatilisation. Despite the substantial losses of B by sublimation, no B isotopic fractionation was observed at 60‐65 C. The property of boron to sublime was used to separate B from an organic matrix. A miniaturized sublimation apparatus, comprising a 5 ml Teflon beaker, and the associated microsublimation technique are described. The 100% boron recovery and the absence of B isotopic fractionation make this method suitable for extracting B from organic‐rich samples.
High‐Precision Trace Element Data for the USGS Reference Materials BCR‐1, BCR‐2, BHVO‐1, BHVO‐2, AGV‐1, AGV‐2, DTS‐1, DTS‐2, GSP‐1 and GSP‐2 by ID‐TIMS and MIC‐SSMS
Authors: Raczek Ingrid , Stoll Brigitte , Hofmann Albrecht W. , Peter Jochum Klaus
Published: May 2007

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.
Determination of Indium and Tellurium in Fifty Nine Geological Reference Materials by Solvent Extraction and Graphite Furnace Atomic Absorption Spectrometry
Authors: Terashima Shigeru
Published: May 2007

The indium (In) and tellurium (Te) contents of fifty nine geological reference materials, issued by several reference material producers (USGS, CRPG, ANRT, GIT‐IWG and GSJ) have been determined by graphite furnace atomic absorption spectrometry, after aqua regia and HF digestion, and extraction of iodide complexes with trioctylmethylammonium (TOMA) ‐ metyl isobutyl ketone (MIBK). Although the interferences from most elements can be minimised by the addition of palladium solution as the matrix modifier, large concentrations of Bi, Cu, Pb or Sn suppress the absorbance of In and/or Te. Samples for analysis were therefore restricted to those in which the concentrations of these interfering elements did not cause a significant interference. The limit of detection was 0.2 ng g−1 In and Te for 1 g test portions. The agreement between the reported results and published data is satisfactory.
Instrumental Neutron Activation Analysis of Estuarine Sediment as a Proposed Reference Material for Environmental Studies
Authors: Waheed Shahida , Wasim Mohammad , Rahman Asma , Ahmad Shujaat
Published: May 2007

The International Atomic Energy Agency (IAEA) Marine Environmental Studies Laboratory (MEL) organised an intercomparison exercise, through its Analytical Quality Control Services (AQCS), for the determination of trace elements in estuarine sediment IAEA‐405, well suited for the characterisation of sediments. The instrumental neutron activation analysis technique (INAA) was developed using a 27 kW low power research reactor. Forty elements in the sediment were determined with a measurement precision varying from 1.8% to 12.3%. IAEA reference materials SL‐1 and SD‐M‐2/TM were analysed throughout this work as quality assurance samples.
New Series of Rock and Sediment Geochemical Reference Materials
Authors: Wang Chunshu , Gu Tiexin , Chi Qinghua , Yan Weidong , Yan Mingcai
Published: May 2007

Certified or reference values for sixty six to sixty seven elements and element oxides are given for geochemical reference materials recently prepared by the Institute of Geophysical and Geochemical Exploration (IGGE), including limestone (GSR‐13), granitic gneiss (GSR‐14), amphibolite (GSR‐15), lake sediment (GSS‐9) and stream sediments (GSD‐1a, GSD‐13, GSD‐14). These samples supplement the GSR 1‐6, GSD1‐8 and GSD 9‐12 certified reference materials already prepared and characterized by the IGGE.
Determination of Chromium, Nickel, Copper and Zinc in Milligram Samples of Geological Materials Using Isotope Dilution High Resolution Inductively Coupled Plasma‐Mass Spectrometry
Authors: Makishima Akio , Kobayashi Katsura , Nakamura Eizo
Published: May 2007

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.
Off‐Line and On‐Line Determination of Eleven Rare Earth Elements in Silicate Rocks by ICP‐AES Using Dowex Minicolumns for Separation of Interfering Elements in Continuous Flow Systems
Authors: Boaventura Geraldo R. , De Oliveira Robson C. , Santelli Ricardo E.
Published: May 2007

The methodologies developed in this work comprise ion‐exchange separation of interfering elements from rare earth elements (Fe, Al and Ca), by using resin minicolumns (Dowex‐50W‐X8 200‐400 mesh) for the determination of La, Ce, Nd, Sm, Eu, Gd, Dy, Ho, Er, Yb and Lu by inductively coupled plasma‐atomic emission spectrometry, using both off‐line and on‐line continuous flow systems. These methods can be used to determine rare earth elements in common silicate rocks, such as granite, basalt, rhyolite and andesite. Thirteen geochemical reference materials were used to evaluate the accuracy and precision of the off‐line and on‐line methods. Chondrite‐normalized diagrams were obtained and compared to values reported in the literature. When compared to conventional procedures, the proposed methods provide fast and low cost rare earth elements determinations in the analysis of silicate rocks. Eighteen samples per hour could be analysed by the proposed method using the automated procedure for the determination of the eleven rare earth elements.
Preparation of a New Geological Survey of Japan Geochemical Reference Material: Coral JCp‐1
Authors: Okai Takashi , Suzuki Atsushi , Kawahata Hodaka , Terashima Shigeru , Imai Noboru
Published: May 2007

A new geochemical reference material, coral Porites sp. JCp‐1 has been prepared by the Geological Survey of Japan (GSJ). Provisional values for twenty one major, minor and trace elements are presented. The homogeneity tests showed that all elements studied are considered to be homogeneously distributed.
The Re‐Os Isotopic System: A Review of Analytical Techniques
Authors: Reisberg Laurie , Meisel Thomas
Published: May 2007

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.
Compositional Heterogeneity in NIST SRM 610‐617 Glasses
Authors: Eggins Stephen M. , Shelley J. Michael G.
Published: May 2007

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.
Determination of Zr, Hf, Th and U by Isotope Dilution and Inductively Coupled Plasma‐Quadrupole Mass Spectrometry After Concomitant Separation Using Extraction Chromatography
Authors: Le Fèvre Brieuc , Pin Christian
Published: May 2007

Four incompatible elements of great geochemical interest were determined concomitantly using a new procedure, combining sample decomposition with a LiBO2 flux and the isotope dilution method. Prior to mass spectrometric measurements with a plasma source quadrupole‐based instrument, the analytes were isolated from matrix elements with high recovery, using a new separation scheme involving a small column comprising the extraction chromatography material, U‐TEVA.Spec. After a detailed description of the experimental procedure, the potential of this method is demonstrated by triplicate analyses of four international reference materials (DNC‐1, W‐2, JA‐1, RGM‐1) spanning a range of analyte concentrations and representative of various silicate rock bulk compositions.
Traceability in Geochemical Analysis
Authors: Kane Jean S. , Potts Philip J.
Published: May 2007

A review is presented of “traceability” and the way this concept can be demonstrated in the analysis of geochemical samples. It is suggested that the two practical methods are (i) by the analysis of appropriate certified reference materials with an evaluation of the agreement between analysed and certified values, and (ii) by the appropriate use of definitive, reference and standard methods of analysis. The differences between these two methods of demonstrating traceability are considered and the difficulties in applying them are discussed.