Reference Values Following ISO Guidelines for Frequently Requested Rock Reference Materials

Abstract

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

Improved composition of Hawaiian basalt BHVO-1 from the application of two new and three conventional recursive discordancy tests

“…Major elements (oxides; from SiO 2 to FeO) are in %m/m and all trace elements (from Cl to W) are in µg/g. Groups of analytical methods according to Velasco-Tapia et al (2001), briefly stated: Gr1 -classical methods; Gr2 -atomic absorption methods; Gr3 -X-ray fluorescence methods; Gr4 -emission spectrometry methods; Gr5 -nuclear methods; Gr6 -mass spectrometry methods; Gr7 -chromatography methods; Gr8 -miscellaneous methods; n out -number of observations after statistical processing; -x-mean; U 99 -total uncertainty of the mean ( -x ) at 99% confidence level; * -recommended value; *1 -recommended value 1 (first recommended value); *2 -recommended value 2 (second recommended value); see the text for %RU 99 and %U diff ; the 99% uncertainty value was calculated in the present work from the reported standard deviation by the original authors (Gladney and Roelandts, 1988;Velasco-Tapia et al, 2001) or from the 95% uncertainty values reported by Jochum et al (2016); the rounding of the data for this table was achieved from the application of the flexible rules put forth by Verma (2005Verma ( , 2016. Figure 6.…”

“…Once again, even for the most recent compilation of Jochum et al (2016), this parameter (%U diff ) varied from about 50% for Ho to about 680% for Gd (Table 3). The statistical information for the REEs obtained from the present methodology (Table 3) is therefore recommended for future applications of quality control.…”

“…Geochemical reference materials (GRMs) play a fundamental role for quality control in geochemistry (e.g., Flanagan, 1973;Abbey et al, 1979;Johnson, 1991;Kane, 1991;Gladney et al, 1992;Balaram et al, 1995;Quevauviller et al, 1999;Namiesnik and Zygmunt, 1999;Thompson et al, 2000;Jochum and Nohl, 2008;Marroquín-Guerra et al, 2009;Pandarinath, 2009;Verma, 2012Verma, , 2016Jochum et al, 2016;Verma et al, 2016aVerma et al, , 2017a. Therefore, their composition should be precisely and accurately known from the application of statistical procedures to interlaboratory analytical data (e.g., Govindaraju, 1984Govindaraju, , 1987Govindaraju, , 1995Roelandts, 1988, 1990;Verma, 1997Verma, , 1998Verma, , 2005Verma, , 2016Verma et al, 1998;Velasco-Tapia et al, 2001;Jochum et al, 2016).…”

“…Therefore, their composition should be precisely and accurately known from the application of statistical procedures to interlaboratory analytical data (e.g., Govindaraju, 1984Govindaraju, , 1987Govindaraju, , 1995Roelandts, 1988, 1990;Verma, 1997Verma, , 1998Verma, , 2005Verma, , 2016Verma et al, 1998;Velasco-Tapia et al, 2001;Jochum et al, 2016). Two main types of statistical procedures (robust and outlier-based) are available for this purpose (e.g., Barnett and Lewis, 1994;Abbey, 1996;Verma, 1997Verma, , 2012Verma et al, 2014).…”

Boninite and boninite-series volcanics in northern Zambales ophiolite: Doubly-vergent subduction initiation along Philippine Sea Plate margins

“…Reproducibility is better than 2 % for REEs and better than 3 % for the rest of the trace elements except for Ta (6.5 %) and Be (3.6 %). Mean percent error is generally within 5-10 % relative to the preferred values of Jochum et al (2016) and Dulski (2001). 5 Major element compositions of constituent mineral phases were determined with a JEOL-8800R electron microprobe at Kanazawa University using 3 m probe diameter, 20 nA probe current and 20 kV accelerating voltage.…”