TY - JOUR A1 - Vogl, Jochen A1 - Mieller, Björn A1 - Noordmann, J. A1 - Rienitz, O. A1 - Malinovskiy, D. T1 - Characterization of a series of absolute isotope reference materials for magnesium: ab initio calibration of the mass spectrometers, and determination of isotopic compositions and relative atomic weights N2 - For the first time, an ab initio calibration for absolute Mg isotope ratios was carried out, without making any a priori assumptions. All quantities influencing the calibration such as the purity of the enriched isotopes or liquid and solid densities were carefully analysed and their associated uncertainties were considered. A second unique aspect was the preparation of three sets of calibration solutions, which were applied to calibrate three multicollector ICPMS instruments by quantifying the correction factors for instrumental mass discrimination. Those fully calibrated mass spectrometers were then used to determine the absolute Mg isotope ratios in three candidate European Reference Materials (ERM)-AE143, -AE144 and -AE145, with ERM-AE143 becoming the new primary isotopic reference material for absolute isotope ratio and delta measurements. The isotope amount ratios of ERM-AE143 are n(25Mg)/n(24Mg) = 0.126590(20) mol/mol and n(26Mg)/n(24Mg) = 0.139362(43) mol/mol, with the resulting isotope amount fractions of x(24Mg) = 0.789920(46) mol/mol, x(25Mg) = 0.099996(14) mol/ mol and x(26Mg) = 0.110085(28) mol/mol and an atomic weight of Ar(Mg) = 24.305017(73); all uncertainties were stated for k = 2. This isotopic composition is identical within uncertainties to those stated on the NIST SRM 980 certificate. The candidate materials ERM-AE144 and -AE145 are isotopically lighter than ERM-AE143 by 1.6 ‰ and 1.3 ‰, respectively, concerning their n(26Mg)/n(24Mg) ratio. The relative combined standard uncertainties are ≤0.1 ‰ for the isotope ratio n(25Mg)/n(24Mg) and ≤0.15 ‰ for the isotope ratio n(26Mg)/ n(24Mg). In addition to characterizing the new isotopic reference materials, it was demonstrated that commonly used fractionation laws are invalid for correcting Mg isotope ratios in multicollector ICPMS as they result in a bias which is not covered by its associated uncertainty. Depending on their type, fractionation laws create a bias up to several per mil, with the exponential law showing the smallest bias between 0.1 ‰ and 0.7 ‰. KW - isotope reference material KW - absolute measurements KW - mass spectrometry KW - atomic weight KW - magnesium PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370931 DO - https://doi.org/10.1039/C6JA00013D SN - 0267-9477 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. VL - 31 IS - 7 SP - 1440 EP - 1458 PB - Royal Society of Chemistry CY - Cambridge, UK AN - OPUS4-37093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen A1 - Yim, Y.-H. A1 - Lee, K.-S. A1 - Goenaga-Infante, H A1 - Malinovskiy, D. A1 - Hill, S. A1 - Ren, T. A1 - Wang, J. A1 - Vocke, R. D. A1 - Murphy, K. E. A1 - Nonose, N. A1 - Rienitz, O. A1 - Noordmann, J. T1 - Certification of ERM-EB400, the first matrix reference material for lead isotope amount ratios, and ERM-AE142, a lead solution providing a lead isotopic composition at the edge of natural variation N2 - Lead isotope amount ratios are commonly used in diverse fields such as archaeometry, geochemistry and forensic science. Currently, five reference materials with certified lead isotope amount ratios are available, namely NIST SRM 981, 982 and 983, GBW-04442 and NMIJ 3681-a. Only NIST SRM 981 and NMIJ 3681-a have approximately natural isotopic compositions, and NIST SRM 981 is predominantly used for correcting mass discrimination/mass fractionation in the applied mass spectrometric procedures. Consequently, there is no other certified reference material available to be used for validation and/or quality control of the analytical procedures applied to lead isotope amount ratio measurements. To fill this gap, two new reference materials have been produced and certified for their lead isotope amount ratios. For both certified reference materials, complete uncertainty budgets have been calculated and SI traceability has been established. This provides the users with independent means for validating and verifying their analytical procedures and for conducting quality control measures. ERM-EB400 is a bronze material with a nominal lead mass fraction of 45 mg kg-1 and certified lead isotope amount ratios of n(206Pb)/n(204Pb) = 18.072(17) mol mol-1, n(207Pb)/n(204Pb) = 15.578(18) mol mol-1 and n(208Pb)/n(204Pb) = 38.075(46) mol mol-1 with the associated expanded uncertainties (k = 2) given in brackets. ERM-AE142 is a high-purity solution of lead in 2% nitric acid with a nominal mass fraction of 100 mg kg-1 and certified Pb isotope amount ratios of n(206Pb)/n(204Pb) = 21.114(17) mol mol-1, n(207Pb)/n(204Pb) = 15.944(17) mol mol-1 and n(208Pb)/n(204Pb) = 39.850(44) mol mol-1 with the associated expanded uncertainties (k = 2) given in brackets. Both materials are specifically designed to fall within the natural lead isotopic variation and to assist users with the validation and verification of their analytical procedures. Note that while one of these reference materials requires the chemical separation of Pb from its matrix (ERM-EB400), the other does not (ERM-AE142). As additional information, δ208/206PbNIST SRM981 values are provided for both materials. For ERM-AE142, a delta value of δ208/206PbNIST SRM981 = -28.21(30) ‰ was obtained, and for ERM-EB400, a delta value of δ208/206PbNIST SRM981 = -129.47(38) ‰ was obtained, with the associated expanded uncertainties (k = 2) given in brackets. KW - Lead isotope variations KW - Radiogenic isotopes KW - Isotope reference material KW - Metrology in chemistry KW - Measurement uncertainty PY - 2019 DO - https://doi.org/10.1111/ggr.12253 SN - 1751-908X SN - 1639-4488 VL - 43 IS - 1 SP - 23 EP - 37 PB - John Wiley & Sons AN - OPUS4-47383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Silke A1 - Roethke, A. A1 - Rienitz, O. A1 - Matschat, Ralf A1 - Schiel, D. A1 - Jaehrling, R. A1 - Goerlitz, V. A1 - Kipphardt, Heinrich T1 - SI-traceable monoelemental solutions on the highest level of accuracy: 25 years from the foundation of CCQM to recent advances in the development of measurement methods N2 - Within the Working Group on Inorganic Analysis (IAWG) of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM) international key comparisons and pilot studies related to inorganic analysis are carried to ensure consistency in this field at the highest level. Some of these comparisons deal directly with the preparation and characterization of monoelemental solutions or with topics, closely related. The importance of monoelemental solutions lies in the fact that almost every measurement in inorganic analysis relies on the comparison with either a reference material, or references in form of solutions, usually (mono)elemental solutions. All quantitative measurement approaches, e.g. isotope dilution or standard addition, need an accurate reference solution made from a well characterized reference material, prepared under full gravimetric control. These primary (monoelemental) solutions do not only serve as arbitrary references/calibration solutions, but they also link up measurement results to the International System of units (SI), this way establishing the so-called metrological traceability to a measurement unit of the SI. Without such solutions on the highest possible level of accuracy and with the smallest possible associated uncertainties (for e.g. element content and/or impurities), an analysis itself can never be as good as it could be with appropriate reference solutions. This article highlights select key comparisons and pilot studies dealing with monoelemental solution related topics within the IAWG from the foundation of CCQM – 25 years ago – up to latest achievements in the field of inorganic analysis. KW - Metrology KW - SI Traceability KW - CCQM PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496080 DO - https://doi.org/10.1088/1681-7575/ab5636 SN - 0026-1394 SN - 1681-7575 SP - 1 EP - 23 PB - IOP CY - Bristol AN - OPUS4-49608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sargent, M A1 - Goenaga-Infante, H A1 - Inagaki, K A1 - Ma, L A1 - Meija, J A1 - Pramann, A A1 - Rienitz, O A1 - Sturgeon, R A1 - Vogl, Jochen A1 - Wang, J A1 - Yang, L T1 - The role of ICP-MS in inorganic chemical metrology N2 - ICP-MS has played a key role in inorganic chemical metrology for 25 years, from the 1993 CIPM feasibility study which led to establishment of the CCQM. Since that time, the Inorganic Analysis Working Group of the CCQM has organised 56 international comparisons involving measurements by ICP-MS and, in a recent comparison, 16 different national institutes submitted their results using the technique. Metrological applications of ICP-MS currently address an enormous range of measurements using a wide variety of instrumentation, calibration strategies and methodologies. This review provides an overview of the ICP-MS field with an emphasis on developments which are of particular relevance to chemical metrology. Examples from CCQM comparisons and the services available from the participants are used to illustrate how the capability and scope of ICP-MS methods have expanded far beyond the expectations of 1993. This is due in part to the research and development Programmes of the national institutes which participate in the CCQM. They have played a key role in advancing new instrumentation and applications for elemental analysis, isotope dilution mass spectrometry, determination of isotopic ratio or composition, and speciation of organometallic compounds. These developments are continuing today, as demonstrated by work in new fields such as heteroatom quantitation of proteins, characterisation and counting of nanoparticles using spICP-MS, and LA-ICP-MS analysis of solid materials. KW - CCQM KW - Metrology KW - Interlaboratory comparison KW - ICP-MS KW - Mass spectrometry KW - Hyphenated KW - Isotope ratio PY - 2019 DO - https://doi.org/10.1088/1681-7575/ab0eac VL - 56 IS - 3 SP - 034005 PB - IOP Publishing AN - OPUS4-47929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -