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 - 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 JF - Journal of analytical atomic spectrometry 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 DO - 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 -