TY - CONF A1 - Rosner, M. A1 - Vogl, Jochen T1 - Approaching realistic measurement uncertainty of Delta11B data T2 - Goldschmidt Conference 2013 T2 - Goldschmidt Conference 2013 CY - Florence, Italy DA - 2013-08-25 PY - 2013 AN - OPUS4-29085 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosner, M. A1 - Vogl, Jochen A1 - Meixner, A. A1 - Kasemann, S. A1 - Noordmann, J. A1 - Rienitz, O. A1 - Schuessler, J. A1 - Kraft, R. A1 - Rabb, S. A1 - Vocke, R. T1 - Intercomparison of d26Mg Values in Mg Isotope RMs and Standards N2 - Accurate measurements of stable isotope abundance ratio variations are often reported using artifact based delta-scales, which rely on suitable isotopic reference materials (iRM) for their realization. For example, variations in the 26Mg/24Mg isotope abundance ratio in natural systems are typically reported as delta26Mg values that represents the relative difference between the 26Mg/24Mg ratio measured in a sample relative to its measurement preferably in an iRM. In the past, such delta26Mg measurements were referenced to NIST SRM 980, the initial zero of the delta26Mg scale. With the development of MC-ICPMS, the detection of small but measurable isotopic differences in different chips of SRM 980 became apparent. It was then replaced by a Mg solution (DSM3), the new zero of the delta26Mg scale. A potential replacement iRM for DSM3 has been developed, ERM-AE143. This iRM has also been measured for its absolute isotope amount ratios1,2 making it traceable to the SI. The results of a delta26Mg intercomparison experiment include the Mg iRMs SRM 980, IRMM-009, ERM-AE143, AE144, AE145 standards DSM3 and Cambridge-1. The intercomparison involved 5 expert laboratories, consisting of 3 national metrological institutes (BAM, NIST, PTB) and 2 scientific research laboratories (GFZ Potsdam, UBremen). The iRMs were measured relative to AE143 and cover a range of ≈5 ‰ in delta26Mg. IRMM-009 has the lowest delta26Mg value while DSM3 has the highest, spanning a range in values that covers natural Mg isotope variations. The 2SD reproducibilities of the individual values from the different laboratories range from 0.02 to 0.26 ‰. The mean delta26Mg values, calculated from the laboratory means however show 2SD reproducibilities varing between 0.025 and 0.093 ‰. Propagated measurement uncertainties suggest a standard uncertainty of about 0.1‰ for delta26Mg determinations. 1 JAAS, 2015, 31,179; 2JAAS, 2016, 31, 1440 T2 - Goldschmidt Conference 2017 CY - Paris, France DA - 13.08.2017 KW - Iisotope reference materials KW - Delta values KW - Magnesium isotope PY - 2017 AN - OPUS4-42742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kazlagic, Anera A1 - Rosner, M. A1 - Vogl, Jochen A1 - Cipriani, A. A1 - Frick, D. A. A1 - Glodny, J. A1 - Hoffmann, J. E. A1 - Hora, J. M. A1 - Irrgeher, J. A1 - Lugli, F. A1 - Magna, T. A1 - Meisel, T. C. A1 - Meixner, A. A1 - Possolo, A. A1 - Pramann, A. A1 - Pribil, M. A1 - Prohaska, T. A1 - Retzmann, A. A1 - Rienitz, O. A1 - Rutherford, D. A1 - Paula-Santos, G. A1 - Tatzel, M. A1 - Widhalm, S. A1 - Willbold, M. A1 - Zuliani, T. T1 - Investigating the differences between MC-ICP-MS and MC-TIMS using conventional 87Sr/86Sr isotope ratios in limestone and slate reference materials N2 - The Federal Institute for Materials Research and Testing (BAM) organised an interlaboratory comparison (ILC) for the characterisation of 87Sr/86Sr isotope ratios in limestone (IAG/CGL ML-3) and Penrhyn slate (IAG OU-6) reference materials by applying the conventional method for 87Sr/86Sr isotope ratios. Samples were sent to thirteen analytical laboratories . Since both samples are powdered, rock materials, dissolution of the sample and Sr isolation via ion exchange chromatography were mandatory. This was done using acid, microwave/acid, bomb/acid digestion or borate fusion and subsequent isolation of Sr by means of commercially available ion exchange resins. In this study, we present and discuss the potential effects that differences between laboratories, and between two instrumental measurement techniques (i.e., MC-ICP-MS and MC-TIMS), may have upon the dispersion of measurement results of the 87Sr/86Sr isotope ratio in the two aforementioned reference materials. We used a statistical mixed effects model to assess the potential effects of both the laboratory and the measurement technique. Consensus values for both materials and associated standard uncertainties {(IAG/CGL ML-3 (0.708245±0.000004) mol/mol; IAG OU-6 (0.729769±0.000008) mol/mol} were estimated by fitting a linear, Gaussian mixed effects model (Pinheiro and Bates 2000) using the R function “lmer” defined in package “lme4”. The statistical results showed that there is no significant effect attributable to differences between instrumental techniques when both materials are considered together, or separately. The p-value of the test of significance of the measurement technique effect is greater than 0.54. For both materials there were statistically significant effects attributable to differences between laboratories when the measurement results for both materials were considered together and separately. This effect is less than 0.00004 in absolute value. However, for neither material did consideration or disregard for such differences induce significant changes in the estimate of the consensus value for the 87Sr/86Sr isotope ratio. Therefore, the effects attributable to differences between instrumental techniques or between laboratories can safely be disregarded when computing the best estimate for the true value of 87Sr/86Sr isotope ratio in these materials, by the community of expert laboratories represented in this study. T2 - GeoAnalysis 2022 CY - Freiberg, Germany DA - 06.08.2022 KW - Isotope ratio KW - Conventional isotope ratio KW - ILC KW - Traceability KW - Uncertainty KW - Isotope reference materials PY - 2022 AN - OPUS4-56848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tütken, T. A1 - Tatzel, Michael A1 - Vogl, Jochen A1 - Rosner, M. T1 - Assessing δ26Mg in bioapatite as proxy for faunivory N2 - Knowledge about feeding behavior is essential to determine trophic interactions and reconstruct predator-prey relationships in modern and past foodwebs. Traditionally, nitrogen isotopes (δ15N) of collagen are used to quantify the ingestion of animal protein, however collagen usually does not preserve over geological time scales. To infer the diet of extinct vertebrates from fossil material more resistant dietary proxies such as Ca and Mg isotopes are needed, which are major elements in the bioapatite of bones and teeth. Magnesium is a bio-essential element that replaces calcium in the bioapatite lattice and bone and enamel δ26Mg values of extant mammals increase systematically along the foodchain [1, 2]. The existing δ26Mg data, however, is scarce, in particular with respect to carnivores, thus still limiting the capability of this dietary proxy to reliably determine trophic differences between plant- and animal-feeders. To better constrain trophic-level effects recorded in Mg isotopes, we analyzed δ26Mg of bioapatite from modern mammals with a focus on faunivores, both carnivores and as yet unexplored insectivores. The trophic level effect of δ26Mg is influenced by the geological substrate which causes isotope variability in δ26Mg of faunal remains between different ecosystems [1, 2]. Therefore, as first-order proxy for sample provenance and to assess potential influences of the bedrock substrate of the animals´ habitats on δ26Mg of bones and teeth, we measured the 87Sr/86Sr on the same specimens. This information will enable us to refine trophic level effects and determine whether δ26Mg can be used to distinguish different faunivores isotopically. This will be of paramount importance for dietary reconstructions of trophic niches in fossil foodwebs. [1] Martin et al. (2014) Geochmica Cosmochimica Acta 130, 12-20. [2] Martin et al. (2015) Proceedings of the National Academy of Sciences 112, 430-435. T2 - Goldschmidt CY - Paris, France DA - 13.08.2017 KW - Magnesium stable isotopes KW - Isotope fractionation KW - Trophic level KW - 87Sr/86Sr KW - Provenance PY - 2017 AN - OPUS4-41535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosner, M. A1 - Vogl, Jochen A1 - Pritzkow, Wolfgang A1 - Voerkelius, S. T1 - 87Sr/86Sr isotope determinations of food products: An analytical overvies and case studies for bell pepper, vanilla and garlic T2 - Food Fraud - the Analytical Tools conference T2 - Food Fraud - the Analytical Tools conference CY - York, England DA - 2014-02-27 PY - 2014 AN - OPUS4-30425 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosner, M. A1 - Vogl, Jochen A1 - Meixner, A. A1 - Kasemann, S. A1 - Noordmann, J. A1 - Rienitz, O. A1 - Schuessler, J. A1 - Kraft, R. A1 - Rabb, S. A1 - Vocke, R. T1 - Intercomparison of delta26Mg Values in Mg Isotope RMs and Standards N2 - Accurate measurements of stable isotope abundance ratio variations are often reported using artifact based delta-scales, which rely on suitable isotopic reference materials (iRM) for their realization. For example, variations in the 26Mg/24Mg isotope abundance ratio in natural systems are typically reported as delta26Mg values that represents the relative difference between the 26Mg/24Mg ratio measured in a sample relative to its measurement preferably in an iRM. In the past, such delta26Mg measurements were referenced to NIST SRM 980, the initial zero of the delta26Mg scale. With the development of MC-ICPMS, the detection of small but measurable isotopic differences in different chips of SRM 980 became apparent. It was then replaced by a Mg solution (DSM3), the new zero of the delta26Mg scale. A potential replacement iRM for DSM3 has been developed, ERM-AE143. This iRM has also been measured for its absolute isotope amount ratios1,2 making it traceable to the SI. The results of an delta26Mg intercomparison experiment include the Mg iRMs SRM 980, IRMM-009, ERM-AE143, AE144, AE145 standards DSM3 and Cambridge-1. The intercomparison involved 5 expert laboratories, consisting of 3 national metrological institutes (BAM, NIST, PTB) and 2 scientific research laboratories (GFZ Potsdam, UBremen). The iRMs were measured relative to AE143 and cover a range of ≈5 ‰ in delta26Mg. IRMM-009 has the lowest delta26Mg value while DSM3 has the highest, spanning a range in values that covers natural Mg isotope variations. The 2SD reproducibilities of the individual values from the different laboratories range from 0.02 to 0.26 ‰. The mean delta26Mg values, calculated from the laboratory means however show 2SD reproducibilities varing between 0.025 and 0.093 ‰. Propagated measurement uncertainties suggest a standard uncertainty of about 0.1‰ for delta26Mg determinations. 1 JAAS, 2015, 31,179; 2JAAS, 2016, 31, 1440 T2 - Goldschmidt Conference 2017 CY - Paris, France DA - 13.08.2017 KW - Magnesium delta scale KW - Isotope reference material KW - Intercalibration PY - 2017 AN - OPUS4-43995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -