1986 Values for Fifteen GSJ Rock Reference Samples, "Igneous Rock Series"

During the five-year period (April 1981 - March 1986), a series of fifteen rock reference samples, "Igneous rock series", has been prepared by the Geological Survey of Japan (GSJ). Based on the data available (published and communicated), consensus values for major, minor and trace elements have been derived; these values are presented for this second series of samples as well as for the first series of two samples, Granodiorite JG-1 and Basalt JB-1.     

ELEMENTAL CONCENTRATIONS IN NINE NEW JAPANESE ROCK REFERENCE SAMPLES

Twenty-eight major, minor and trace elements in nine new rock reference samples of Geological Survey of Japan (GSJ), JA-2, JA-3 JB-1a, JG-1a, JG-2, JG-3, JF-1, JF-2 and JP-1 have been determined using atomic absorption spectrometry, flame emission spectrometry and wet chemical techniques.     

Silver, Cadmium and Lead Contents of Some Rock Reference Samples

A series of rock reference samples have been analyzed for Ag, Cd and Pb. All elements were determined from a single digest using a method involving solvent extraction and flameless atomic absorption spectrophotometry.     

Determination of the Platinum-Group Elements and Gold in Twenty Rock Reference Materials by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after Pre-Concentration by Nickel Sulfide Fire Assay

The platinum-group elements (PGE) and gold have been determined in twenty international rock reference materials by inductively coupled plasma-mass spectrometry (ICP-MS) after pre-concentration by a nickel sulfide fire assay. It was possible to achieve determination limits for a 50 g sample that ranged from 1 pg g^-1 (Rh) to 23 pg g^-1 (Au). Compared to published certified and recommended values for rock reference materials, the trueness of the method was found to be good. However, in some cases we observed large deviations for all elements in the sub 10 ng g^-1 range within individual reference sample splits. Our results show that the PGE and Au are inhomogeneously distributed in the reference materials analysed here, where they are present in low concentrations, using 50 g test portions.     

Improvements in Digestion Protocols for Trace Element and Isotope Determinations in Stream and Lake Sediment Reference Materials (JSd-1, JSd-2, JSd-3, JLk-1 and LKSD-1)

Total dissolution is a critical step in geochemical analysis. Despite the number of published protocols, this issue still draws attention for sediment samples, which are particularly difficult to dissolve due to the common occurrence and high abundance of refractory phases such as zircon. We present tests of different chemical digestion procedures carried out on reference materials (RM) of stream (JSd-1, JSd-2 and JSd-3) and lake (JLk-1 and LKSD-1) sediments from the Geological Survey of Japan (GSJ) and the Canadian Certified Reference Material Programme (CCRPM). We demonstrate that the fusion technique is not appropriate for our studies as not all elements of interest were recovered and blank levels were too high to permit further Sr and Pb isotopic composition measurements. Similarly, conventional HF+HNO₃ dissolution methods were not efficient enough for detrital samples. Our preferred method involved using high pressure Teflon® vessel bombs in association with HClO₄. This protocol ensured a complete dissolution of the powder, as well as a complete recovery of trace elements. Moreover, blank levels were sufficiently low that Sr or Pb isotope compositions could be measured from the same mother solution. We also tested the homogeneity of RM powders by performing tests on various amount of powder.     

Determination of the Rare Earth Elements in Thirteen GSJ Silicate Rock Reference Samples by Secondary Ion Mass Spectrometry

Rare earth elements were determined by secondary ion mass spectrometry (SIMS) for 12 igneous rocks and one feldspar separate from the new rock reference samples of the Geological Survey of Japan. The study presents an expanded application of the SIMS facility.     

Reference Values Following ISO Guidelines for Frequently Requested Rock Reference Materials

We present new reference values for nineteen USGS, GSJ and GIT‐IWG rock reference materials that belong to the most accessed samples of the GeoReM database. The determination of the reference values and their uncertainties at the 95% confidence level follows as closely as possible ISO guidelines and the Certification Protocol of the International Association of Geoanalysts. We used analytical data obtained by the state‐of‐the‐art techniques published mainly in the last 20 years and available in GeoReM. The data are grouped into four categories of different levels of metrological confidence, starting with isotope dilution mass spectrometry as a primary method. Data quality was checked by careful investigation of analytical procedures and by the application of the Horwitz function. As a result, we assign a new and more reliable set of reference values and respective uncertainties for major, minor and a large group of trace elements of the nineteen investigated rock reference materials.     

Solid Sampling Atomic Absorption Determination Of Silver in Silicate Rock Reference Samples. Application to a Homogeneity Study of Silver In a One-Ton Two-Mica Granite Reference Sample

Silver content of silicate rook samples rarely exceeds 200 ppb. For determining such low levels of silver, a solid sampling flame atomic absorption method has been developed and has been applied to the analysis of several silicate rock reference samples. These results are compared with the sparse published data. Using silver as an example, the usefulness of solid sampling procedures for testing the repartition of volatile trace elements during the processing of new rock reference samples is illustrated.     

Accurate Determination of Nickel in South African Primary and Secondary Geochemical Reference Materials by Cation Exchange Chromatography and Atomic Absorption Spectrometry

Nickel in the six SA primary (NIMROCS) and fourteen secondary reference materials as well as in a phosphate rock has been determined accurately by means of atomic absorption spectrometry. A selective and quantitative twocolumn ion exchange separation procedure, using AG50W-X4 cation exchange resin, is employed for the separation of nickel from all other elements. The accuracy and precision of the described method are demonstrated by the analysis of synthetic rock solutions containing various amounts of nickel.     

Routine Control of Accuracy in Silicate Rock Analysis by X-Ray Fluorescence Spectrometry

In this study, we used the modified Horwitz expression (H_c= 0.01c^0.8495, which gives the precision as a function of concentration) to evaluate and control the accuracy of results of silicate rock analysis obtained by X-ray fluorescence spectrometry. This expression is currently used by the organisers of the GeoPT international proficiency tests, to assign the precision limits of each analyte and subsequently to evaluate the data provided by laboratories whose main application is geochemistry. Results for major and trace elements, determined in glass disk and pressed pellets, respectively, were evaluated. Nine international silicate rock reference materials were analysed and results were compared to the recommended values plus and minus the limits given by the above expression. Those limits are easily attained for most major elements, but not for trace elements. Sample preparation and sub-sampling contributions to precision were evaluated by analysis of an in-house reference sample. In our results, precision does not follow the Horwitz expression relationship with concentration. It is known that the final accuracy in XRF analysis depends strongly on instrumental settings and on the uncertainties associated with the certified or recommended values of the reference materials used to calibrate the spectrometer, but our results indicate that the precision expression can be useful, especially to inspect and correct calibration curves and to check routine instrumental accuracy.     

遥感岩性识别研究的发展趋势--遥感与航空放射性信息集成

岩石的吸收光谱主要是由杂质、包体、蚀变及替代成分产生的,每种岩石都难以形成象它的组成成分那样具有可分辨的很清晰的光谱特征;不同类型的岩石放射性元素的含量和分布特征是不同的,岩石放射性信息是岩性识别研究的重要判据。遥感与航空放射性信息的集成．既能提取光谱图像中的光语信息和空间纹理信息。又可利用航空放射性信息常常具有的甚至是诊断性的岩性识别能谱标志。能明显提高识别岩性的精度,更重要的是能谱不受值被的影响,有利于识别植被覆盖区的岩性。因此,这可能是遥感岩性识别研究的发展趋势之一。     

Accurate Determination of Cobalt in South African Primary and Secondary Geochemical Reference Materials by Cation Exchange Chromatography and Atomic Absorption Spectrometry

Cobalt in the six S.A. primary (NIMROCS) and fourteen secondary reference samples as well as in a phosphate rock has been determined accurately by means of atomic absorption spectrometry. A selective and quantitative ion exchange separation procedure, using a 20 g column of AG50W-X8 cation exchange resin and 0.4 M hydrochloric acid-86% acetone and 1 M hydrochloric acid-80% acetone as eluting agents, is employed for the separation of cobalt from all other elements. The accuracy and precision of the described method are demonstrated by the analysis of synthetic rock solutions containing various amounts of cobalt. Amounts of 1, 10 and 100 μg of cobalt can be determined with a coefficient of variation of 1%, 0.3% and 0.2%. respectively.     

Boron Determination in Twenty One Silicate Rock Reference Materials by Isotope Dilution ICP-MS

The concentration of boron was determined in twenty one geochemical reference materials (silicate rocks) by isotope dilution inductively coupled plasma-mass spectrometry. Boron was extracted from the rocks using HF digestion, suppressing boron volatilisation through boron-mannitol complexation. Sample solutions, in a diluted HCl matrix, were analysed by ICP-MS without any separation of boron from the matrix elements. The results obtained were in agreement with the literature data and indicate that using the described procedure, trace amounts of boron can be very easily determined in complex matrices with rapidity and precision. With the instrumentation and reagents used in this study, this procedure can be used for the determination of 0.5 μg g⁻¹ boron in a 15 0 mg silicate rock sample. Replicate analyses of the twenty one geochemical reference materials (GRM), ranging in boron concentration from 1.35 to 15 7 μg g⁻¹, yielded precisions (relative standard deviation) varying between 0.9 and 9.8%.     

Neutron Activation Analysis of Nine GSJ Sedimentary Rock Reference Samples

Nine rock reference samples "Sedimentary rock series" issued by the Geological Survey of Japan (GSJ) were analysed for up to 31 elements by neutron activation analysis (NAA); 14MeV-NAA for Si and Al, fission track method for U, radiochemical and instrumental NAA for rare-earth elements, and instrumental NAA for the remaining elements, with reactor neutrons for the latter three. The present results are compared with reported values.     

微波密闭消解-等离子体质谱法测定岩石样品中的稀土元素

建立了有微波密封ＨＦ＋ＨＮＯ３消解样品,等离子体质谱测定岩石样品中１５个稀土元素的分方法。用该方法对国内外岩石标准品进行测定,结果表明稀土元素的测定值与标准值之间的相对偏差小于５％,检出限为（０．１－０．９）＊１０＾－９,多次测定结果的相对标准偏差在１．３％－５．２％。各类实际岩石样品中稀土元素的分析结果均与地质规律相符,进一步证明了方法的可靠性。     

Determination of Ga,Ge, Mo,Ag, Cd,In, Sn,Sb, W,Tl and Bi in USGS Whole‐Rock Reference Materials by Standard Addition ICP‐MS

A procedure for determining a wide range of chalcophile and siderophile elements in typical crustal rocks using standard addition and ICP‐SFMS (inductively coupled plasma sector field mass spectrometry) is presented. New results for Ga, Ge, Mo, Ag, Cd, In, Sn, Sb, W, Tl and Bi abundances in USGS whole‐rock reference materials AGV‐2, BHVO‐1, BIR‐1, G‐2, GSP‐1 and W‐2 are reported using this analytical procedure. Intermediate precision of means based on multiple dissolved aliquots of each USGS reference material was 10% RSD or better for Ga, Ge, In and Sn in all, and similarly good for Ag, Cd, Sb, Tl and Bi in most reference materials. Poorer intermediate precision of Mo and W measurements in several reference materials is probably due to higher analytical blanks on these elements and powder heterogeneity due to a sulfide‐related nugget effect in the specific case of Mo in GSP‐1. Results for all elements fell within the range of available published data with the exception of Ag, which yielded systematically higher concentrations than found in the literature for five of the six reference materials, likely reflecting interference from unresolved polyatomic species.     

Comparison of Rare-Earth Element Data Obtained by Neutron Activation Analysis Using International Rock and Multielement Solution Standards

The authors have used a high-purity multielement solution, containing known quantities of individual Pare earth elements, as a reference standard in neutron activation analysis of rare earths in several international standard rocks. The data obtained by the authors have been compared with those obtained using the international standard rock Basalt BCR-1 as a reference material. The authors'data compare favourably with those obtained by other workers, particularly for the more basic rock types, and encourages the authors to suggest that a multielement solution standard can be used successfully for neutron activation analysis of rave earth elements. High values obtained for Ce in Basalt BCR-1, however, might indicate that the behaviour of Ce in solution needs further investigation.     

rare Earth Elements in Six New GSJ Standard Rock Samples as Determined by Inductively Coupled Plasma Atomic Emission Spectrometry

Analytical data of rare earth elements (REEs) are presented for six new standard rock samples (JB-2, JB-3, JR-1, JR-2, JA-1, and JGb-1) issued by the Geological Survey of Japan. These data have been simultaneously determined by inductively coupled plasma atomic emission spectrometry.     

Determination of Rare Earth Elements in Sixteen Silicate Reference Samples by Secondary Ion Mass Spectrometry Using Conventional Energy Filtering Technique*

Rare earth elements were determined by secondary ion mass spectrometry for 13 silicate rock samples, ranging from ultramafic-mafic to acidic compositions, 2 feldspar and 1 biotite separates. As a whole, the investigated samples are characterized by matrices and rare earth elements spectra covering most geological applications. The present data are compared with reference values. The advantage of using secondary ion mass spectrometry as a fundamental tool for trace element detection in bulk samples in the few ppm-ppb region is demonstrated.