Brigitte Stoll

We present new reference values for the NIST SRM 610–617 glasses following ISO guidelines and the International Association of Geoanalysts’ protocol. Uncertainties at the 95% confidence level (CL) have been determined for bulk‐ and micro‐analytical purposes. In contrast to former compilation procedures, this approach delivers data that consider present‐day requirements of data quality. New analytical data and the nearly complete data set of the GeoReM database were used for this study. Data quality was checked by the application of the Horwitz function and by a careful investigation of analytical procedures. We have determined quantitatively possible element inhomogeneities using different test portion masses of 1, 0.1 and 0.02 μg. Although avoiding the rim region of the glass wafers, we found moderate inhomogeneities of several chalcophile/siderophile elements and gross inhomogeneities of Ni, Se, Pd and Pt at small test portion masses. The extent of inhomogeneity was included in the determination of uncertainties. While the new reference values agree with the NIST certified values with the one exception of Mn in SRM 610, they typically differ by as much as 10% from the Pearce et al. (1997) values in current use. In a few cases (P, S, Cl, Ta, Re) the discrepancies are even higher.

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. Nous avons développé une base de données: GeoReM (http://georem.mpch-mainz.gwdg.de) regroupant les matériaux de références et standards isotopique d'intérêt géochimique et minéralogique. Les matériaux de référence englobent les poudres de roches de l'USGS, du GSJ et du GIT-IWG, les verres synthétiques et naturels provenant de NIST, USGS, MPI-DING, ainsi que des minéraux (par ex. le zircon 91500), des solutions de référence isotopique (par ex. La Jolla, E&A, NIST SRM 981) d'eau de rivière et d'eau de mer. GeoReM est une base de données relationnelle qui suit le principe des trois bases de données EARTHCHEM. Elle contient les données publiées et les données de compilation (concentrations en éléments majeurs et en trace, rapports d'isotopes radiogéniques ou stables), les données concernant les valeurs analytiques, telles que l'incertitude, son type, la méthode d'analyse employée et le laboratoire d'analyse. Les informations sur l'échantillon et les références sont aussi incluses. Il est possible d'interroger la base de données de trois manières différentes : 1) par nom d'échantillon ou type de matériau, 2) par critère chimique et 3) bibliographique. Quelques application typiques sont décrites. Ce jour (Octobre 2005) GeoReM contient plus de 750 matériaux géologiques de référence, 6000 ensembles de données et les références de 650 publications.

We present new analytical data of major and trace elements for the geological MPI‐DING glasses KL2‐G, ML3B‐G, StHs6/80‐G, GOR128‐G, GOR132‐G, BM90/21‐G, T1‐G, and ATHO‐G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA‐ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA‐ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high‐precision bulk techniques, such as TIMS and MC‐ICPMS. In addition, LA‐ICPMS and SIMS isotope data of B, Li, and Pb are presented.

The USGS reference glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G were investigated by different analytical techniques. All these materials have a geological (basaltic) matrix and are therefore useful in igneous geochemistry as matrix-matched reference materials for microanalytical techniques. The new GS glasses have trace elements in groups at concentration levels of about < 0.01, 5, 50 and 500 μg g-1. Their major element compositions have been determined by EPMA, and trace elements have been analysed by LA-ICP-MS and two isotope dilution techniques using TIMS and ICP-MS. EPMA and LA-ICP-MS analyses indicated that the USGS reference glasses are homogeneous at the μm to mm scale with respect to major (variations < 1-2%) and most trace elements (variations 1-4%). Trace element data obtained from the different analytical techniques agreed within an uncertainty of 1-5%, indicating that between method results are comparable. Therefore, the preliminary working values for the four USGS GS glasses calculated from these data have a low level of uncertainty. Les verres de référence de l'USGS GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G et BIR-1G ont étéétudiés par différentes techniques analytiques. Tous ces matériaux ont une matrice géologique (basaltique) particulièrement adaptée à toute technique de microanalyse en géochimie endogène. Ces nouveaux verres ont des teneurs en éléments en trace qui se répartissent en quatre groupes de concentrations aux alentours de < 0.01, 5, 50 et 500 μg g-1. Les éléments majeurs ont été analysés par EPMA et les éléments en trace par LA-ICP-MS et avec deux techniques de dilution isotopique couplées à un TIMS et un ICP-MS. Les analyses par EPMA et par LA-ICP-MS montrent que les verres de référence de l'USGS sont homogènes aux échelles du μm au mm pour tous les majeurs (variations inférieures à 1-2%) et la plupart des traces (variations entre 1 et 4%). Pour les éléments en traces, les résultats obtenus par plusieurs techniques analytiques concordent aux barres d'erreurs près (1-5%), montrant l'agrément entre les méthodes. En conséquence, les valeurs de travail préliminaires données pour ces quatre verres GS de l'USGS sont affectées d'une incertitude faible.