Mass Spectrometric Isotope Dilution Determination Of Palladium in Geochemical Reference Samples

Fifteen geochemical reference samples have been analysed for palladium using the stable isotope dilution technique. These include seven USGS, five CRPG and three CCRMP samples. Our results ape in reasonable agreement with the presently accepted values for the USGS samples, but are significantly lower than the present CCRMP values. Our data for the CRPG samples are the first to be published. This is the first reported study of the determination of palladium in silicate samples using the isctope dilution technique.     

Analyses of the United States Geological Survey Geochemical Exploration Reference Samples GXR-I to - 6

Analyses of the United States Geological Survey geochemical exploration reference samples (GXR) 1–6 are reported for 36 elements and compared with published values.     

Determination of Iodine in Thirty Two International Geochemical Reference Materials

Thirty two geochemical reference samples have been analysed for their iodine contents by a pyrohydrolysis extraction technique, followed by colourimetry. In spite of the existence of few reported values for iodine, limiting comparison with results from this study, the four available "reference" values show good agreement with the work reported here.     

Report (1968–1978) on Two Mica Reference Samples: Biotite Mica-Fe and Phlogopite Mica-Mg

Since 1967–68, two mica reference samples, Biotite Mica-Fe and Phlogopite Mica-Mg, were made available to several geochemical laboratories. The analytical data reported during the past ten years by 142 geoanalysts belonging to 74 international laboratories are presented and assessed for deriving preferred values. Reaomrmended or proposed values are assigned for major, minor and several trace elements. The biotite Mica-Fe is better characterized for its chemical composition than the Phlogopite Mica-Mg. Both the samples are also proposed as geochronological standards. Because very few mica reference samples have been processed in large quantities, the international geochemiaal community is invited to contribute further useful data.     

Determination of Fluorine in Eighty International Geochemical Reference Samples by Proton Induced Gamma Ray Emission Spectrometry (PIGE)

Fluorine content has been determined non destructively in eighty international geochemical reference samples (GRS) including rocks, soils, sediments, minerals and ores, by proton induced gamma ray emission spectrometry (PIGE) using the nuclear reaction ¹⁹F(p,αγ) ¹⁶O. Under our operating conditions, the detection limit is around 25 ppm. Our analytical results are compared with the presently preferred values when available or with other published data. The general agreement between this work and reported values is reasonably good. The present paper includes results on several GRS for which existing data are rather scarce or even inexistant.     

Instrumental Neutron Activation Analysis of Twenty-Nine International Geochemical Reference Samples

Results of measurements of twenty-seven elements, most of them in trace amounts, by Instrumental Neutron Activation Analysis (INAA) in twenty-nine international geochemical reference samples from Canada, U.S.A., Japan, France and South Africa, are reported and compared with available literature values. In general, our data agree well with literature values. The disagreement of our results (e.g., Zr in Canadian syenites and several trace elements in USGS ultrabasic rocks) with those reported by other workers is briefly discussed and ways of improving INAA are pointed out. The present report includes data on several trace elements for which existing data are rather scarce.     

Mineralogical Associations of Arsenic and Antimony in Thirty Five Geochemical Reference Materials by Sequential Extraction with Hydride Generation and Atomic Absorption Spectrometry

A method is described to estimate the chemical forms of arsenic (As) and antimony (Sb) in a variety of geochemical reference materials, combining a sequential extraction scheme with hydride generation and atomic absorption spectrometry (HG-AAS). The fractions dissolved by sequential extraction are empirically defined as the exchangeable, EDTA soluble, oxide, sulfide and residual fractions. The amount of As and Sb in the EDTA soluble fraction have been derived mainly from oxide phases, and partly from carbonate minerals. Most sulfide minerals in common geological samples were considered to be dissolved with the digestion of 0.7 mol l⁻¹ NaOCl, but only small fraction of arsenopyrite and loellingite in ores could be dissolved in this way. Satisfactory agreement was observed between the sum of the As or Sb values from exchangeable to residual fractions and the reported total As or Sb values, with a few exceptions. Analytical results of As and Sb for thirty five geochemical reference materials are tabulated, and geochemical and mineralogical features are discussed.     

Determination of Bromine and Iodine in Twenty-three Geochemical Reference Materials by ICP-MS

Trace amounts (from nanogram to microgram levels) of bromine and iodine were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in twenty-three geochemical reference materials issued by the GSJ, USGS, IAEA etc. The pyrohydrolysis technique was used to separate bromine and iodine from samples analysed in the form of powder. The accuracy and precision of the experimental values were assessed by the comparative analysis of well established reference materials such as USGS AGV-1, BCR-1 and IGGE GBW07312. The measured values agreed well with reported values within a 10% error range. We also report reliable new data for these elements in these geochemical reference materials.     

A SELF-CONSISTENT COMPILATION OF ELEMENTAL CONCENTRATION DATA FOR 93 GEOCHEMICAL REFERENCE SAMPLES

Concentration data obtained by instrumental neutron activation analysis (INAA) are presented for up to 36 chemical elements in 93 geochemical reference samples, including some for which there are little previous data. Because all data are based on at least three independent analyses, and for many of the data the uncertainty associated with counting is an insignificant source of error, the values presented here are considered of higher precision than generally reported by INAA. Information on subsampling error (sample heterogeneity) is also presented.     

Instrumental Neutron Activation Analysis of Two French Geochemical Reference Samples - Basalt BR and Biotite Mica-Fe

Instrumental neutron activation analysis results for 20 trace elements (Sc, Cr, Co, Ni, Rb, Cs, Ba, La, Ce, Nd, Sm, Eu, Gd, Tb, Tm, Yb, Lu, Hf, Ta, Th) and for two major elements (Na and Fe) in two geochemical reference samples issued by the "Centre de Recherches Pétrographiques et Géochimiques" are reported and compared with available literature values. In general our results agree well with recommended or proposed values.     

Mass Spectrometric Isotope Dilution Analyses Of Barium in Geochemical Reference Samples

Twenty-four geochemical reference samples have been analysed far barium using the stable isotope dilution technique. These include five CRPG, ten ANRT, six Nimroc and two CCRMP samples together with the Tonalite from Tanzania, Duplicate analyses have been made in each case and our values for barium are believed to be accurate to approximately 3 %. In general, our results are in good agreement with the published data except for Nimroc samples where our data are consistently lower than the presently accepted values. No evidence of sample inhomogeneities was observed in the present work.     

Inductively Coupled Plasma Determination Of Nine Rare-Earth Elements In Sixty International Geochemical Reference Samples

Data for nine rare-earth elements (REE) determined by inductively coupled plasma spectrometry (ICP-AES) in sixty international geochemical reference samples (igneous and sedimentary rocks, soils and sediments) are presented. The method is based on acid digestion of the sample and cation-exchange separation from matrix elements. Good agreement is generally achieved between the results of this work and the recent compilation values. The present paper includes analytical data on several reference materials for which existing data are rather scarce or even inexistent     

Application of an Ion-Selective Electrode Method to the Determination of Chloride in 41 International Geochemical Reference Materials

Determinations of trace amounts (with one exception) of chloride are reported for 41 international geochemical reference standards, 12 of which have no previously reported literature values. All determinations were made by the chloride-specific ion-selective electrode method of Aruscavage and Campbell with certain refinements. Chlorine is separated from most other elements in geologic materials by acid-dissolution in a gas diffusion cell, and is subsequently determined as the chloride ion in basic solution. A statistical F-test was applied to 19 of the standards for which three bottles of each were analyzed in triplicate with no failures. All these standards, plus the other 22 for which six analyses were performed on a single bottle, exhibited a relative standard deviation of 1-6% for concentrations of chloride >50 ppm. For most samples chloride values agree well both with available, reported experimental values and with recommended or consensus values.     

Spectrophotometric Determination of Zirconium In Some Geochemical Reference Sampies

The zirconium content of some geochemical reference samples has been determined by a spectrophotometric procedure. In general, our values are in agreement with those recommended or published.     

TRACE ELEMENT DETERMINATIONS FOR USGS BASALT BHVO-1 AND NIST STANDARD REFERENCE MATERIALS 278, 688 AND 694 BY INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY

Results are presented for 26 to 30 trace elements determined in four rock reference materials of geochemical interest: USGS Basalt BHVO-1, Rhyolite Obsidian NIST 278, Basalt NIST688, and Phosphate Rock NIST694. Determinations were made by inductively coupled plasma mass spectrometry (ICP-MS). Good agreement was obtained among solution standard comparison and standard addition analytical techniques, and among samples prepared with different dissolution methods. Generally good agreement was obtained between determined trace element values and values reported in the literature.     

Selection of Multifractal Scaling Breaks andSeparation of Geochemical andGeophysical Anomaly

1Multifractalities have been observed and estimated formany quantities in physics, chemistry, as well as earth andspace sciences (see a review in Agterberg, 20011 Cheng,1999al Agterberg et al., 1993 1 Schertzer and Love joy, 1991).The multifractal theory has provided a superior distributiontype for describing the complex measures in comparison withthe ordinary statistical distributions. The former usually involves the multiple moments and parameters (Cheng, 1999alAgterberg et al., 1993 1 Sc…     

GEOCHEMICAL STANDARD REFERENCE SAMPLES GSD 9–12, GSS 1–8 AND GSR 1–6

The 18 Chinese geochemical standard reference samples GSD 9-12 (stream sediments), GSS 1-8 (soils) and GSR 1-6 (rocks) were prepared after GSD 1-8 (stream sediments) for even wider and increasing needs of geology, exploration geochemistry and geochemical analysis. Usable values of 41 trace, minor and major elements of the 18 samples were published in 1984. In the following two years, efforts were concentrated on the determination of other elements, most of which are more difficult to determine accurately and hence not many data were available in the literature. At the same time, additional data on the 41 elements already evaluated were also submitted. In all, 155 234 results were available along with the 35 284 analytical data submitted. The processing of samples, the examination of sample homogeneity, the plan of collaborative analysis of the samples, and the criteria for defining the recommended values are described. The recommended or reference values of the 72 constituents, to-gether with the 35 284 analytical data of the 18 samples are published in this paper.     

Fractional Determination of Gold in Twenty Six Geological Reference Materials by Sequential Extraction with Graphite Furnace Atomic Absorption Spectrometry

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.     

GRAPHICAL COMPARISON OF GEOCHEMICAL RESULTS

Comparison of analytical results obtained for geochemical reference samples with accepted results is tedious and error prone. Graphical representation facilitates comparison. Nevertheless, currently used diagrams lack representativeness when a wide range of concentrations are studied. A newly designed graph representing normalized results against concentrations is proposed. It allows comparison of a wide range of concentrations and helps detect analytical problems for particular ranges of concentrations.     

1992 compilation of analytical data for rare-earth elements, scandium, yttrium, zirconium and hafnium in twenty-six GSJ reference samples

Abstract: Analytical data for fourteen rare-earth elements, scandium, yttrium, zirconium and hafnium, received by May 1992, have been compiled on twenty-six GSJ (Geological Survey of Japan) reference samples. Seventeen of them are 'Igneous rock series' and nine are "Sedimentary rock series". The reported data including personal communication were evaluated under the consideration on analytical methods and geochemical evidences. No significant difference has been observed between the values obtained by the different analytical methods. Based on the selected available data, 1992 compilation values were tabulated.