TY - JOUR A1 - Molloy, J. L. A1 - Winchester, M. R. A1 - Butler, T. A. A1 - Possolo, A. M. A1 - Rienitz, O. A1 - Roethke, A. A1 - Goerlitz, V. A1 - Caciano de Sena, R. A1 - Dominguez Almeida, M. A1 - Yang, L. A1 - Methven, B. A1 - Nadeau, K. A1 - Romero Arancibia, P. A1 - Bing, W. A1 - Tao, Z. A1 - Snell, J. A1 - Vogl, Jochen A1 - Koenig, Maren A1 - Kotnala, R. K. A1 - Swarupa Tripathy, S. A1 - Elishian, C. A1 - Ketrin, R. A1 - Suzuki, T. A1 - Oduor Okumu, T. A1 - Yim, Y.-H. A1 - Heo, S. W. A1 - Min, H. S. A1 - Sub Han, M. A1 - Lim, Y. A1 - Velina Lara Manzano, J. A1 - Segoviano Regalado, F. A1 - Arvizu Torres, M. A1 - Valle Moya, E. A1 - Buzoianu, M. A1 - Sobina, A. A1 - Zyskin, V. A1 - Sobina, E. A1 - Migal, P. A1 - Linsky, M. A1 - Can, S. Z. A1 - Ari, B. A1 - Goenaga Infante, H. T1 - CCQM-K143 Comparison of Copper Calibration Solutions Prepared by NMIs/DIs N2 - CCQM-K143 is a key comparison that assesses participants’ ability to prepare single element calibration solutions. Preparing calibration solutions properly is the cornerstone of establishing a traceability link to the International System of Units (SI), and therefore should be tested in order to confirm the validity of CCQM comparisons of more complex materials. CCQM-K143 consisted of participants each preparing a single copper calibration solution at 10 g/kg copper mass fraction and shipping 10 bottled aliquots of that solution to the coordinating laboratory, the National Institute of Standards and Technology (NIST). The masses and mass fraction for the prepared solutions were documented with the submitted samples. The solutions prepared by all participants were measured at NIST by high performance inductively coupled plasma optical emission spectroscopy (HP-ICP-OES). The intensity measurements for copper were not mapped onto values of mass fraction via calibration. Instead, ratios were computed between the measurements for copper and simultaneous measurements for manganese, the internal standard, and all subsequent data reductions, including the computation of the KCRV and the degrees of equivalence, were based on these ratios. Other than for two participants whose measurement results appeared to suffer from calculation or preparation errors, all unilateral degrees of equivalence showed that the measured values did not differ significantly from the KCRV. These results were confirmed by a second set of ICP-OES measurements performed by the Physikalisch-Technische Bundesanstalt (PTB). CCQM-K143 showed that participants are capable of preparing calibration solutions starting from high purity, assayed copper metal. Similar steps are involved when preparing solutions for other elements, so it seems safe to infer that similar capabilities should prevail when preparing many different, single-element solutions. KW - Metrology KW - Primary calibration solution KW - Traceability PY - 2020 U6 - https://doi.org/10.1088/0026-1394/58/1A/08006 SN - 0026-1394 VL - 58 IS - 1A SP - 08006 PB - IOP Science CY - Cambridge AN - OPUS4-51983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen A1 - Rosner, M. A1 - Kasemann, S. A. A1 - Kraft, R. A1 - Meixner, A. A1 - Noordmann, J. A1 - Rabb, S. A1 - Rienitz, O. A1 - Schuessler, J. A. A1 - Tatzel, Michael A1 - Vocke, R. D. T1 - Intercalibration of Mg isotope delta scales and realisation of SI traceability for Mg isotope amount ratios and isotope delta values N2 - The continuous improvement of analytical procedures using multi-collector technologies in ICP-mass spectrometry has led to an increased demand for isotope standards with improved homogeneity and reduced measurement uncertainty. For magnesium, this has led to a variety of available standards with different quality levels ranging from artefact standards to isotope reference materials certified for absolute isotope ratios. This required an intercalibration of all standards and reference materials, which we present in this interlaboratory comparison study. The materials Cambridge1, DSM3, ERMAE143, ERM-AE144, ERM-AE145, IRMM-009 and NIST SRM 980 were cross-calibrated with expanded measurement uncertainties (95% confidence level) of less than 0.030‰ for the δ25/24Mg values and less than 0.037‰ for the δ26/24Mg values. Thus, comparability of all magnesium isotope delta (δ) measurements based on these standards and reference materials is established. Further, ERM-AE143 anchors all magnesium δ-scales to absolute isotope ratios and therefore establishes SI traceability, here traceability to the SI base unit mole. This applies especially to the DSM3 scale, which is proposed to be maintained. With ERM-AE144 and ERM-AE145, which are product and educt of a sublimation-condensation process, for the first time a set of isotope reference materials is available with a published value for the apparent triple isotope fractionation exponent θapp, the fractionation relationship ln α(25/24Mg)/ln α(26/24Mg). KW - Delta scale KW - Traceability KW - Scale anchor KW - Absolute isotope ratio KW - Comparability KW - Triple isotope fractionation PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-511557 SN - 1751-908X VL - 44 IS - 3 SP - 439 EP - 457 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-51155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen T1 - The triple-isotope calibration approach: a universal and standard-free calibration approach for obtaining absolute isotope ratios of multi-isotopic elements N2 - The theory of a new calibration approach for obtaining absolute isotope ratios of multi-isotopic elements without the use of any standard has been developed. The calibration approach basically uses the difference in the instrumental isotope fractionation of two different types of mass spectrometers, leading to two different fractionation lines in a three-isotope diagram. When measuring the same sample with both mass spectrometers, the different fractionation lines have one point in common: this is the ‘true’ logarithmized isotope ratio pair of the sample. Thus, the intersection of both fractionation lines provides us with the absolute isotope ratios of the sample. This theory has been tested in practice by measuring Cd and of Pb isotope ratios in the certified reference materials BAM-I012 and NIST SRM981 by thermal ionization mass spectrometry and by inductively coupled plasma mass spectrometry while varying the ionization conditions for both mass spectrometers. With this experiment, the theory could be verified, and absolute isotope ratios were obtained, which were metrologically compatible with the certified isotope ratios. The so-obtained absolute isotope ratios are biased by − 0.5% in average, which should be improved with further developments of the method. This calibration approach is universal, as it can be applied to all elements with three or more isotopes and it is not limited to the type of mass spectrometers applied; it can be applied as well to secondary ion mass spectrometry or others. Additionally, this approach provides information on the fractionation process itself via the triple-isotope fractionation exponent θ. KW - Triple isotope fractionation KW - Absolute isotope ratio KW - Mass spectrometry KW - Calibration KW - Uncertainty PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-516364 VL - 413 IS - 3 SP - 821 EP - 826 PB - Springer Verlag AN - OPUS4-51636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rienitz, O. A1 - Pramann, A. A1 - Vogl, Jochen A1 - Lee, K.-S. A1 - Yim, Y.-H. A1 - Malinovskiy, D. A1 - Hill, S. A1 - Dunn, P. A1 - Goenaga-Infante, H. A1 - Ren, T. A1 - Wang, J. A1 - Vocke jr., R. D. A1 - Rabb, S: A. A1 - Narukawa, T. A1 - Yang, L. A1 - Mester, Z. A1 - Meija, J. A1 - Aref'ev, D. G. A1 - Marchin, V. A1 - Sharin, A. G. A1 - Bulanov, A. D. A1 - Potapov, A. M. A1 - Otopkova, P. A. A1 - Kessel, R. T1 - The comparability of the determination of the molar mass of silicon highly enriched in 28Si: results of the CCQM-P160 interlaboratory comparison and additional external measurements N2 - An international comparison study on the accurate determination of the molar mass M(Si) of silicon artificially enriched in 28Si (x(28Si) > 0.9999 mol mol−1) has been completed. The measurements were part of the high level CCQM-P160 pilot study assessing the ability of National Metrology Institutes (NMIs) and Designated Institutes (DIs) to make such measurements at the lowest possible levels of measurement uncertainty and to identify possible difficulties when measuring this kind of sample. This study supports the molar mass measurements critical to disseminating the silicon route to realizing the new definitions for the kilogram and the mole. Measurements were also made by one external research institute and an external company. The different institutes were free to choose their experimental (mass spectrometric) set-ups and equipment, thereby enabling also the comparison of different techniques. The investigated material was a chemically pure, polycrystalline silicon material. The subsequent modified single crystalline secondary product of this material was intended for the production of silicon which was used for two additional spheres in the context of the redetermination of the Avogadro constant NA, required for the revision of the International System of Units (SI) via fundamental constants which came into force from May 2019. The CCQM pilot study was organized by Physikalisch-Technische Bundesanstalt (PTB). Aqueous silicon solutions were shipped to all participating institutions. The data analysis as well as the uncertainty modelling and calculation of the results was predefined. The participants were provided with an uncertainty budget as a GUM Workbench® file as well as a free software license for the duration of the comparison. The agreement of the values of the molar mass (M(Si) = 27.976 942 577 g mol−1) was excellent with ten out of 11 results reported within the range of relative uncertainty of 1 × 10−8 required for the revision of the SI. KW - Absolute isotope ratio KW - Molar mass KW - Avogadro constant KW - Revision of the SI PY - 2020 U6 - https://doi.org/10.1088/1681-7575/abbdbf VL - 57 IS - 6 SP - 065028 PB - IOP Science CY - Cambridge AN - OPUS4-51500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rienitz, O. A1 - Jährling, R. A1 - Noordmann, J. A1 - Pape, C. A1 - Röhker, K. A1 - Vogl, Jochen A1 - Manzano, J. V. L. A1 - Kozlowski, W. A1 - Caciano de Siena, R. A1 - Marques Rodrigues, J. A1 - Galli, A. H. A1 - Yim, Y.-H. A1 - Lee, K.-S. A1 - Lee, J. H. A1 - Min, H.-S. A1 - Chingbo, C. A1 - Naijie, S. A1 - Qian, W. A1 - Ren, T. A1 - Jun, W. A1 - Tangpaisarnkul, N. A1 - Suzuki, T. A1 - Nonose, N. A1 - Mester, Z. A1 - Yang, L. A1 - Pagliano, E. A1 - Greenberg, P. A1 - Mariassy, M. A1 - Näykki, T. A1 - Cankur, O. A1 - Coskun, F. G. A1 - Ari, B. A1 - Can, S. Z. T1 - CCQM-K122 "Anionic impurities and lead in salt solutions" N2 - The determination of the mass fractions of bromide, sulfate, and lead as well as the isotopic composition of the lead (expressed as the molar mass and the amount fractions of all four stable lead isotopes) in an aqueous solution of sodium chloride with a mass fraction of 0.15 g/g was the subject of this comparison. Even though the mass fractions ranged from 3 μg/g (bromide) to 50 ng/g (lead), almost all results reported agreed with the according KCRVs. KW - Absolute isotope ratio KW - Lead isotope ratios KW - Metrology KW - Traceability PY - 2020 U6 - https://doi.org/10.1088/0026-1394/57/1A/08012 VL - 57 IS - 1A SP - 8012 PB - IOP Science AN - OPUS4-51156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pramann, A. A1 - Vogl, Jochen A1 - Rienitz, O. T1 - The Uncertainty Paradox: Molar Mass of Enriched Versus Natural Silicon Used in the XRCD Method N2 - The X-ray crystal density method uses silicon spheres highly enriched in 28Si as a primary method for the dissemination of the SI base unit kilogram yielding smallest possible uncertainties associated with the mass m within a few parts in 10-8. This study compares different available and newly developed analytical methods and their results for the determination of the molar mass M of silicon highly enriched in 28Si (Me) and of silicon (Mx) with an almost natural isotopic distribution. While for Me relative uncertainties urel(Me) in the lower 10-9 range are obtained routinely, it was not possible to fall below a value of urel(Mx) < 4 x 10-6 in the case of natural silicon, which is approximately three orders of magnitude larger. The application of the state-of the-art isotope ratio mass spectrometry accompanied with sophisticated thoroughly investigated methods suggests an intrinsic cause for the large uncertainty associated with the molar mass of natural silicon compared to the enriched material. KW - silicon KW - Molar mass KW - Isotope ratios KW - SI KW - Kilogram KW - Mole KW - XRCD method PY - 2020 U6 - https://doi.org/10.1007/s12647-020-00408-y VL - 35 SP - 499 EP - 510 PB - Springer Verlag AN - OPUS4-51637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -