TY - JOUR A1 - Gusarova, Tamara A1 - Methven, B. A1 - Kipphardt, Heinrich A1 - Sturgeon, R. A1 - Matschat, Ralf A1 - Panne, Ulrich T1 - Calibration of double focusing glow discharge mass spectrometry instruments with pin-shaped synthetic standards N2 - Calibration of two commercially available glow discharge double focusing mass spectrometers, the VG 9000 and Element GD, is described using synthetic pin standards pressed from solution doped copper and zinc matrices. A special pressing die was developed for this purpose and optimal results were obtained with the highest possible pressures, i.e., 95 kN·cm- 2. This calibration approach permits the determination of trace element mass fractions down to µg·kg- 1 with small uncertainties and additionally provides traceability of the GD-MS results in the most direct manner to the SI (International System of Units). Results were validated by concurrent measurements of a number of compact copper and zinc certified reference materials. The impact of the sample pin cross-section (circular or square) was investigated with the use of a new pin-sample holder system for the Element GD. The pin-sample holder was designed by the manufacturer for pin-samples having circular cross-section; however, samples with square pin cross-section were also shown to provide acceptable results. Relative Sensitivity Factors for some 50 analytes in copper (VG 9000, Element GD) and zinc matrices (VG 9000) are presented. The field of applicability of GD-MS may be considerably extended via analysis of pin geometry samples based on their ease of preparation, especially with respect to the accuracy and traceability of the results and the enhanced number of analytes which can be reliably calibrated using such samples. KW - Glow discharge KW - Pin sample KW - Calibration PY - 2011 U6 - https://doi.org/10.1016/j.sab.2011.12.001 SN - 0584-8547 SN - 0038-6987 VL - 66 IS - 11-12 SP - 847 EP - 854 PB - Elsevier CY - Amsterdam AN - OPUS4-25346 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rudtsch, S. A1 - Fahr, M. A1 - Fischer, J. A1 - Gusarova, Tamara A1 - Kipphardt, Heinrich A1 - Matschat, Ralf T1 - High-Purity Fixed Points of the ITS-90 with Traceable Analysis of Impurity Contents N2 - The International Temperature Scale of 1990 (ITS-90) is based on thermodynamic equilibrium states of ideally pure substances. The largest contribution to the uncertainty budgets of most metallic fixed points is the influence of impurities on the fixed-point temperature. Therefore, a traceable chemical analysis of the remaining impurities with small uncertainty is the basis of further progress. Further requirements are better knowledge of the phase diagrams at very low impurity contents, impurity segregation, and the quantification and correction of thermal effects during a fixed-point realization. In this article, current and future activities at PTB and BAM in order to develop improved metallic fixed-point cells of the ITS-90 are reviewed. KW - Chemical analysis KW - Fixed points KW - Impurities KW - ITS-90 KW - Phase diagrams KW - Thermal effects PY - 2008 U6 - https://doi.org/10.1007/s10765-007-0358-9 SN - 0195-928X SN - 1572-9567 VL - 29 IS - 1 SP - 139 EP - 150 PB - Springer CY - Dordrecht AN - OPUS4-17455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gusarova, Tamara A1 - Hofmann, T. A1 - Kipphardt, Heinrich A1 - Venzago, C. A1 - Matschat, Ralf A1 - Panne, Ulrich T1 - Comparison of different calibration strategies for the analysis of zinc and other pure metals by using the GD-MS instruments VG 9000 and element GD N2 - Synthetic pressed metal powder standards doped with standard solutions were used for the calibration of both commercially available high resolution GD-MS instruments Element GD and VG 9000 for zinc matrix. Different quantification procedures (IBR, Standard RSF, matrix matched RSF from the calibration with CRMs and use of doped synthetic standards) are compared using zinc matrix as an example, whereas the calibration with doped pellets turned out to be the best quantification technique for high-purity materials. The applicability of the Standard RSF concept is scrutinised. In this context, RSF values for several Matrices (Co, Cu, Fe, In and Zn) are reported additionally. PY - 2010 U6 - https://doi.org/10.1039/b921649a SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 314 EP - 321 PB - Royal Society of Chemistry CY - London AN - OPUS4-22376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gusarova, Tamara A1 - Hodoroaba, Vasile-Dan A1 - Matschat, Ralf A1 - Kipphardt, Heinrich A1 - Panne, Ulrich T1 - Exploitation of the hollow cathode effect for sensitivity enhancement of Grimm-type DC glow discharge optical emission spectroscopy N2 - The hollow cathode (HC) effect was investigated in non-cooled 15 mm deep drilled flat metallic analytical samples that were easy to prepare. The deep cavity used ("complete HC" in contrast to "recessed HC" with 2-3 mm deep cavity) intensified the HC effect notably and therefore distinctly improved the detection power of the common GD-OES with planar cathodes. A signal enhancement of up to a factor of 150, not reported earlier, in comparison with flat conventional samples was achieved. A better separation of the analytical lines from spectral interferences was observed when the HC assembly was applied. Additionally, an effect of strongly enhanced intensities of atomic lines and somewhat decreased intensities of ionic lines was detected in the case of HC in comparison to usual planar cathodes. The investigations were carried out with samples of copper, steel and zinc matrices using both the same and individually optimised glow discharge (GD) electrical parameters. KW - Hollow cathode KW - Grimm type glow discharge KW - Emission spectroscopy KW - GD-OES KW - Sensitivity PY - 2009 U6 - https://doi.org/10.1039/b814977a SN - 0267-9477 SN - 1364-5544 VL - 24 SP - 680 EP - 684 PB - Royal Society of Chemistry CY - London AN - OPUS4-19600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rudtsch, S. A1 - Gusarova, Tamara A1 - Aulich, A. A1 - Fahr, M. A1 - Fischer, J. A1 - Kipphardt, Heinrich A1 - Matschat, Ralf A1 - Panne, Ulrich T1 - Procedure for the impurity-related correction at the indium fixed-point N2 - Determining the influence of impurities on the fixed-point emperatures of the ITS-90 requires the completion of several tasks. In this paper, the Progress made at Physikalisch-Technische Bundesanstalt (PTB) and BAMFederal Institute for Materials Research and Testing is presented and remaining questions are discussed. The projected characterization procedure at PTB, which is based on the established SIE method (sum of the individual estimates), using a new indium fixed-point cell is described as an example. This procedure includes an SI-traceable chemical Analysis of the material in the fixed-point cell with sufficiently low uncertainties, the individual experimental determination of the influence of the quantified impurities on the fixed-point temperature, and the establishment of direct links to the phase-transition temperatures of the national standard and of an assumed material of ideal purity. A characteristic difference to the common practice is the chemical analysis of the fixed-point metal being done after determining the cell’s freezing temperature. This allows for the detection and consideration of contamination and purification effects due to the filling process, or due to the contact with the carbon crucible and other parts of the fixed-point cell. A chemical analysis of an indium fixed-point was carried out by BAM with relative measurement uncertainties below 30 % which have not been previously achieved. The results provide evidence for the precipitation of some impurities, which is apparently inconsistent with the corresponding binary phase diagrams, but was explained in a recent publication. Implications for the use of the SIE method shall be described briefly at the end. KW - Chemical analysis KW - Fixed-points KW - Impurities KW - ITS-90 PY - 2011 U6 - https://doi.org/10.1007/s10765-011-0915-0 SN - 0195-928X SN - 1572-9567 VL - 32 IS - 1-2 SP - 293 EP - 302 PB - Springer CY - Dordrecht AN - OPUS4-23373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kipphardt, Heinrich A1 - Matschat, Ralf A1 - Vogl, Jochen A1 - Gusarova, Tamara A1 - Czerwensky, Michael A1 - Heinrich, Hans-Joachim A1 - Hioki, A. A1 - Konopelko, L.A. A1 - Methven, B. A1 - Miura, T. A1 - Petersen, O. A1 - Riebe, Gundel A1 - Sturgeon, R. A1 - Turk, G.C. A1 - Yu, L. L. T1 - Purity determination as needed for the realisation of primary standards for elemental determination: status of international comparability N2 - Within the National Metrology Institutes (NMIs) and designated laboratories, an interlaboratory comparison, CCQM-P107, was conducted to verify the degree of international comparability concerning the results of purity analysis. The mass fractions of Ag, Bi, Cd, Cr, Ni, Tl at the lower mg/kg-level in a high purity zinc material were determined, but the real measurand in metrological sense was the sum of the six mass fractions. Homogeneity was investigated by glow discharge mass spectrometry, reference values were obtained using isotope dilution mass spectrometry. Six NMIs participated, contributing eight independent data sets. The agreement amongst the results of the participants, their median and the agreement with the reference values were usually excellent and in almost all cases below the target uncertainty of 30% relative. In this manner, the accuracy of results and the comparability between the participants was demonstrated to be established. KW - Interlaboratory comparison KW - Purity analysis KW - High purity metals KW - CCQM-P107 KW - Zinc PY - 2010 U6 - https://doi.org/10.1007/s00769-009-0557-0 SN - 0949-1775 SN - 1432-0517 VL - 15 IS - 1 SP - 29 EP - 37 PB - Springer CY - Berlin AN - OPUS4-20767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -