TY - JOUR A1 - Balski, Matthias A1 - Emmerling, Franziska A1 - Kipphardt, Heinrich A1 - Panne, Ulrich T1 - Determination of boron in silicon without use of additional complexing agents JF - Analytical methods N2 - Methods for the determination of boron in various matrices described in the literature usually employ complexing agents like mannitol to retain the volatile boron species during matrix evaporation steps. However, also relatively high boron recoveries from silicon containing samples have been reported when no complexing agents were added to the digestion acids. The mechanism behind this matrix-dependant recovery has been investigated by studying the boron recovery in the analysis of solar grade silicon. It was found that the NH4+ ion formed by the reduction of nitric acid during sample digestion is responsible for the higher recovery of boron, which leads to a possible analysis method without the use of complexing agents if the sample preparation procedure is carefully optimized. KW - Boron KW - Complexing agents KW - Matrix evaporation KW - Sample enrichment PY - 2014 DO - https://doi.org/10.1039/c4ay00410h SN - 1759-9660 SN - 1759-9679 VL - 6 IS - 12 SP - 4003 EP - 4008 PB - RSC Publ. CY - Cambridge AN - OPUS4-30956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balski, Matthias A1 - Kipphardt, Heinrich A1 - Berger, Achim A1 - Meyer, S. A1 - Panne, Ulrich T1 - Determination of impurities in solar grade silicon by inductively coupled plasma sector field mass spectrometry (ICP-SFMS) subsequent to matrix evaporation JF - Analytical methods N2 - A method for the determination of 22 trace impurities in solar grade silicon after dissolution in a mixture of HF and HNO3 and subsequent matrix evaporation is reported. The presented method involves a simple, inexpensive, one-vessel sample preparation apparatus design. The recoveries of B, Na, Mg, Al, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Mo, Sb, W, and Tl at 250 µg kg-1 level are in the range of 93 to 108%. After careful selection of monitored isotopes and their respective resolutions, a sector field mass spectrometer has been used to carry out the measurements. Limits of determination down to 120 ng kg-1 have been obtained using a calibration by three-point standard addition. The method was tested on diluted NIST SRM 57b silicon powder as well as on synthetic test samples and also applied successfully on raw solar grade silicon samples in an interlaboratory comparison including NAA. KW - Solar grade silicon KW - Matrix separation KW - Sector field mass spectrometry PY - 2014 DO - https://doi.org/10.1039/C3AY41213J SN - 1759-9660 SN - 1759-9679 VL - 6 IS - 1 SP - 77 EP - 85 PB - RSC Publ. CY - Cambridge AN - OPUS4-29893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gopala, Anil A1 - Mahn, S. A1 - Panne, Ulrich A1 - Kipphardt, Heinrich T1 - In situ vacuum thermal mass spectroscopy for the selection of an environmentally friendly, energy saving catalytic additive and optimization of the process by a novel ignition mechanism JF - RSC Advances N2 - We report herein the utilization of vacuum thermal mass spectrometry (VTMS) for the selection of an environmentally friendly, energy saving catalytic additive and a novel ignition mechanism, which is complementary to catalysis for the reduction of zinc oxide with carbon. PY - 2013 DO - https://doi.org/10.1039/c3ra40223a SN - 2046-2069 VL - 3 IS - 25 SP - 9677 EP - 9680 PB - RSC Publishing CY - London AN - OPUS4-28659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 JF - Spectrochimica acta B 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 DO - 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 - 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 JF - International Journal of Thermophysics 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 DO - 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 - Gopala, Anil A1 - Kipphardt, Heinrich A1 - Matschat, Ralf A1 - Panne, Ulrich T1 - Use of mass spectrometric detection as a versatile process monitoring tool: reduction patterns in a milled ZnO/Al mixture JF - Analytical methods N2 - Mass spectrometric detection can play a prominent role in the assessment of different reactions occurring at varied temperatures in a milled ZnO/Al mixture. This is the first time that online mass spectrometric information was used as a tool for monitoring and understanding the chemical reduction process mechanism. We have observed four different types of reaction taking place: (1) distillation of Zn metal, (2) reduction of ZnO by activated Al, (3) melting of Al and finally (4) reduction of ZnO by inactivated Al. The experimental conditions and results observed by QMS were supported with literature data and physical measurement data from X-Ray Diffraction (XRD) which gave us an idea about the complex reaction cascade which occurred during the formation of the zinc metal. PY - 2010 DO - https://doi.org/10.1039/c0ay00057d SN - 1759-9660 SN - 1759-9679 VL - 2 SP - 451 EP - 454 PB - RSC Publ. CY - Cambridge AN - OPUS4-21291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gopala, Anil A1 - Zellmann, M. A1 - Kipphardt, Heinrich A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Mass spectrometric study of the impurity profile in Zn during reduction-distillation of ZnO with activated and inactivated Al JF - Journal of the American society for mass spectrometry N2 - In this work, we report on the application of hyphenated gas source mass spectrometry to study and understand the mechanism of the reduction-distillation of ZnO using Al powder as reductant in its activated and inactivated form. The experiments revealed that the purity of the Zn metal produced were superior using activated Al with respect to inactivated Al, i.e., m5N8 (99.9998% metallic based) versus m5N3. The achieved purity levels of Zn and the absence of high volatile Cd, Mg, and Sb impurities in the gas phase and the material collected were explained with respect to the impurity elements free-energy values, vapor pressure data, and an observed scavenging effect of the Ta crucible, which was supported by the on-line observed mass spectrometric profiles of the residual gas. PY - 2010 DO - https://doi.org/10.1016/j.jasms.2010.04.009 SN - 1044-0305 VL - 21 IS - 9 SP - 1620 EP - 1623 PB - Elsevier CY - New York, NY AN - OPUS4-21910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gopala, Anil A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Kipphardt, Heinrich T1 - Real time monitoring of chemical transformations during catalytic reduction using gas source mass spectrometry: carbon/zinc carbonate hydroxide JF - Journal of analytical atomic spectrometry N2 - We report herein the utilization of a vacuum reduction distillation system (VRDS) coupled with mass spectrometry (MS) to characterize chemical transformations in thermal analysis. The system initially designed to monitor metal purification by distillation is applied for the first time to the catalytic reaction of in situ formed nickel oxide during the carbothermic reduction of zinc oxide. PY - 2010 DO - https://doi.org/10.1039/c004179c SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 1378 EP - 1380 PB - Royal Society of Chemistry CY - London AN - OPUS4-21911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gopala, Anil A1 - Kipphardt, Heinrich A1 - Matschat, Ralf A1 - Panne, Ulrich T1 - Process methodology for the small scale production of m6N5 purity zinc using a resistance heated vacuum distillation system JF - Materials chemistry and physics N2 - Ultra high purity Zn (m6N5) was obtained through triple vacuum distillation using an m4N5 Zn as input material. High-volatile impurities were removed from the zinc matrix by vacuum evaporation, while traces having lower volatility than the matrix remained in the residual material after finishing of the entire purification process. The time required for the removal of the main high-volatile impurity (Cd) was monitored using a connected gas source mass spectrometer. During distillation the Zn vapor of the distillate was condensed on the cap of a glassy carbon crucible which was water cooled by a movable copper block. The temperatures were optimized for the removal of the volatiles and for the distillation process using vapor pressure data. High resolution glow discharge mass spectrometry was applied for the analysis and purity evaluation of the distilled and input zinc. The analysis confirmed the reduction of the metallic impurities from 43 mg kg-1 to 0.5 mg kg-1 (m6N5) after three consecutive vacuum distillations. An increase in the grain size and a decrease in the micro-hardness were observed for the purified Zn material. KW - Ultra high purity KW - Vacuum distillation KW - High resolution glow discharge mass KW - Spectrometry KW - Micro-hardness KW - Zinc KW - Purification PY - 2010 DO - https://doi.org/10.1016/j.matchemphys.2010.02.080 SN - 0254-0584 VL - 122 IS - 1 SP - 151 EP - 155 PB - Elsevier CY - Amsterdam AN - OPUS4-21127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Traub, Heike A1 - Czerwensky, Michael A1 - Matschat, Ralf A1 - Kipphardt, Heinrich A1 - Panne, Ulrich T1 - Different calibration strategies for the analysis of pure copper metal by nanosecond laser ablation inductively coupled plasma mass spectrometry JF - Journal of analytical atomic spectrometry N2 - In this work, different calibration strategies for the determination of trace elements in pure copper metal by nanosecond laser ablation ICP-MS were investigated. In addition to certified reference materials (CRMs), pellets of doped copper powder were used for calibration. The micro homogeneity of the CRMs as well as the solution-doped pellets was sufficient to use them as calibration samples in combination with a laser spot size of 200 µm. In contrast, pellets doped with analytes in solid form showed a significant heterogeneity. For most of the investigated analytes and copper CRMs the measured mass fractions were within ± 20% of their certified values when other copper CRMs were used as calibration samples. When solution-doped powder pellets were used as calibration samples a systematic trend towards mass fractions below the certified values was observed for nearly all elements determined in the analysed CRMs. Thermal fractionation effects during the ablation of the solution-doped pellets were suspected as the extent of the fractionation depends on the irradiance, whereas fractionation is reduced at higher irradiance. PY - 2010 DO - https://doi.org/10.1039/b915564c SN - 0267-9477 SN - 1364-5544 VL - 25 IS - 5 SP - 690 EP - 696 PB - Royal Society of Chemistry CY - London AN - OPUS4-21195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -