TY - JOUR A1 - Brenneis, Rudolf A1 - Kley, Gerd A1 - Köcher, Peter A1 - Michaelis, Matthias T1 - Untersuchungen zur ZnO-Reduktion beim Schmelzen von Filterstäuben im elektrischen Lichtbogenofen KW - Filterstäube aus Müllverbrennungsanlagen KW - Elektrischer Lichtbogenofen KW - Inertisierung KW - ZnO-Reduktion KW - Röntgenfluoreszenzanalyse PY - 2008 SN - 0027-2957 SN - 1863-9763 VL - 40 IS - 6 SP - 294 EP - 300 PB - Erich Schmidt CY - Berlin AN - OPUS4-17692 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noack, Siegfried A1 - Matschat, Ralf A1 - Michaelis, Matthias T1 - Zur Homogenitätsuntersuchung an kompakten metallischen Referenzmaterialproben - Vergleich der Präzisionseigenschaften der Funken-Emissionsspektrometrie und der Röntgenfluoreszenzanalyse KW - Röntgenfluoreszenzanalyse KW - Funkenspektrometrie KW - Homogenitätstest KW - Verfahrenspräzision KW - Referenzmaterialien PY - 2009 SN - 1613-2394 VL - 62 IS - 4 SP - 210 EP - 223 PB - GDMB, Ges. für Bergbau, Metallurgie, Rohstoff- und Umwelttechnik CY - Clausthal-Zellerfeld AN - OPUS4-20054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Michaelis, Matthias T1 - Certification of the mass fractions of Pt, Pd and Rh in a used car catalyst reference material N2 - The high economic value of catalysts containing the platinum group elements platinum, rhodium and palladium as active components causes the need to be able to measure the precious metal loading with small uncertainty and to have suitable certified reference materials fulfilling high demands on the quality of the certified values. In European Reference Material ERM®-EB504, a used cordierite-based car catalyst material, mass fractions of platinum, palladium and rhodium were certified. The raw material was milled, homogenised and annealed before analysis. Seventeen laboratories experienced in precious metals analysis participated in the certification interlaboratory comparison, most of them analysing with inductively coupled plasma optical emission spectrometry using different sample pretreatment techniques. Homogeneity testing was carried out using X-ray fluorescence spectrometry. The certified mass fractions of Pt, Pd and Rh and their expanded uncertainties (k = 2) in ERM®-EB504 are (1777 ± 15), (279 ± 6) and (338 ± 4) mg/kg respectively. KW - Precious metals KW - CRM KW - European reference material KW - Platinum KW - Rhodium KW - Palladium KW - ICP OES PY - 2009 DO - https://doi.org/10.1007/s00769-009-0508-9 SN - 0949-1775 SN - 1432-0517 VL - 14 IS - 5 SP - 277 EP - 280 PB - Springer CY - Berlin AN - OPUS4-19349 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Michaelis, Matthias T1 - Einsatz der RFA bei der Zertifzierung von Referenzmaterialien N2 - Einsatz der RFA bei der Zertifizierung von Referenzmaterialien Der Bedarf an Referenzmaterialien für die chem. Analytik steigt stetig. Nur durch Einsatz moderner Analysenmethoden kann die Nachfrage gedeckt werden. Die RFA als hochpräzises Verfahren, ist aufgrund der sehr geringen Verfahrensstreuung in der Lage, bei der Beurteilung der Homogenität des Kanditatenmaterials entscheidene Informationen über die Analytverteilung zu liefern. Zur Zertifizierung von Referenzmaterial wird in der anorg. chem. Analytik häufig die ICP-OES eingesetzt. Die RFA, in Kombination mit der Rekonstitutions- und Boratschmelztechnik, ist bei der Zertifizierung eine Analysenmethode, die sich in Bezug auf Probenvorbereitung und Messmethodik grundsätzlich von der ICP-OES unterscheidet. Dadurch trägt sie zur analytischen Methodenvielfalt und damit zur Richtigkeit des zertifizierten Wertes bei und erfüllt zudem im vollsten Maße die Anforderung an metrologischer Rückführbarkeit. T2 - 12. Anwendertreffen Röntgenfluoreszenz- und Funkenemissionsspektrometrie; Universität Dortmund CY - Dortmund, Germany DA - 2005-03-14 PY - 2005 AN - OPUS4-7248 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Michaelis, Matthias T1 - Nichts wissen macht nichts? Erfahrungen mit dem "Standardlosen" Analyseprogramm IQ+. N2 - Nichts wissen macht nichts? Erfahrungen mit dem "Standardlosen" Analyseprogramm IQ+. Die moderne semiquantitative Röntgenfluoreszensanalyse bietet als feststoffanalytisches Verfahren die Möglichkeit, chem. Elemente einer völlig unbekannten Probe schnell und zerstörungsfrei qualitativ und quantitativ zu bestimmen. Im Gegensatz zur konventionellen Kalibration, die sich auf eine Elementauswahl beschränkt, wird bei der semiquantitativen RFA das gesamte mögliche Elementspektrum (5?Z?92, B-U) erfasst. Nach einem Scan, der sich in anregungs- und erfassungsoptimierte Teilscans aufteilt, werden aus den Peaklagen zunächst die Elemente erkannt. Aus den Peakhöhen werden dann, über iterativ arbeitende Fundamentalparameter gestützte Rechenprogramme, die Elemente quantitativ bestimmt. Die gebräuchlichen semiquantitativen Programme basieren auf Universalkalibrationen wobei die Probenart (Metall, Glas, Pressling…) nicht berücksichtigt wird. In der BAM wurde nun begonnen, probenspezifische Kalibrationen zu erstellen, so dass die Richtigkeit des Analyseergebnisses gesteigert werden konnte. Ziel ist es, einen großen Teil der analytischen Fragestellungen an ständig wechselnd zusammengesetzten Proben feststoffanalytisch mit der RFA bearbeitbar zu machen. T2 - Panalytical Symposium 2006 CY - Kassel, Germany DA - 2006-09-19 PY - 2006 AN - OPUS4-13479 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wienold, Julia A1 - Recknagel, Sebastian A1 - Scharf, Holger A1 - Hoppe, Marion A1 - Michaelis, Matthias T1 - Elemental analysis of printed circuit boards considering the ROHS regulations N2 - The EU RoHS Directive (2002/95/EC of the European Parliament and of the Council) bans the placing of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants on the EU market. It necessitates methods for the evaluation of RoHS compliance of assembled electronic equipment. In this study mounted printed circuit boards from personal computers were analyzed on their content of the three elements Cd, Pb and Hg which were limited by the EU RoHS directive. Main focus of the investigations was the influence of sample pre-treatment on the precision and reproducibility of the results. The sample preparation steps used were based on the guidelines given in EN 62321. Five different types of dissolution procedures were tested on different subsequent steps of sample treatment like cutting and milling. Elemental analysis was carried out using ICP–OES, XRF and CV–AFS (Hg). The results obtained showed that for decision-making with respect to RoHS compliance a size reduction of the material to be analyzed to particles ≤1.5 mm can already be sufficient. However, to ensure analytical results with relative standard deviations of less than 20%, as recommended by the EN 62321, a much larger effort for sample processing towards smaller particle sizes might be required which strongly depends on the mass fraction of the element under investigation. KW - RoHS KW - Printed circuit boards KW - Electrotechnical products KW - Elemental composition PY - 2011 DO - https://doi.org/10.1016/j.wasman.2010.10.002 SN - 0956-053X VL - 31 IS - 3 SP - 530 EP - 535 PB - Elsevier Ltd. CY - New York, NY AN - OPUS4-23986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lange, Britta A1 - Recknagel, Sebastian A1 - Czerwensky, Michael A1 - Matschat, Ralf A1 - Michaelis, Matthias A1 - Peplinski, Burkhard A1 - Panne, Ulrich T1 - Analysis of pure copper - a comparison of analytical mehods KW - Pure copper KW - Elemental analytical mehtods KW - Reference material KW - Sample dissolution PY - 2008 DO - https://doi.org/10.1007/s00604-007-0849-1 SN - 0026-3672 SN - 1436-5073 VL - 160 SP - 97 EP - 107 PB - Springer CY - Wien AN - OPUS4-17565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matiushkina, Anna A1 - Abram, Sarah-Luise A1 - Tavernaro, Isabella A1 - Richstein, R. A1 - Reithofer, M. R. A1 - Andresen, Elina A1 - Michaelis, Matthias A1 - Koch, Matthias A1 - Resch-Genger, Ute T1 - Quantifying Citrate Surface Ligands on Iron Oxide Nanoparticles with TGA, CHN Analysis, NMR, and RP-HPLC with UV Detection N2 - Although citrate is frequently used as a surface ligand for nanomaterials (NMs) such as metal, metal oxide, and lanthanide-based NMs in hydrophilic environments due to its biocompatibility and simple replacement by other more strongly binding ligands in postsynthetic surface modification reactions, its quantification on NM surfaces has rarely been addressed. Here, we present a multimethod approach for citrate quantification on iron oxide nanoparticles (IONPs) broadly applied in the life and material sciences. Methods explored include thermogravimetric (TGA) and elemental (CHN) analysis, providing citrate-nonspecific information on the IONP coating, simple photometry, and citrate-selective reversed-phase high-performance liquid chromatography (RP-HPLC) with absorption (UV) detection and quantitative nuclear magnetic resonance spectroscopy (qNMR). Challenges originating from the strongly absorbing magnetic NM and paramagnetic iron species interfering with optical and NMR Methods were overcome by suitable sample preparation workflows. Our multimethod approach to citrate quantification highlights the advantages of combining specific and unspecific methods for characterizing NM Surface chemistry and method cross-validation. It also demonstrates that chemically nonselective measurements can favor an overestimation of the amount of a specific surface ligand by signal contributions from molecules remaining on the NM surface, e.g., from particle synthesis, such as initially employed ligands and/or surfactants. Our results emphasize the potential of underexplored selective RPHPLC for quantifying ligands on NMs, which does not require a multistep sample preparation workflow such as qNMR for many NMs and provides a higher sensitivity. These findings can pave the road to future applications of versatile HPLC methods in NM characterization. KW - Advanced material KW - Functional group KW - Iron oxide KW - Ligand KW - Nano KW - Particle KW - Quantification KW - Surface analysis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648632 DO - https://doi.org/10.1021/acs.analchem.5c03024 SN - 0003-2700 VL - 97 IS - 36 SP - 19627 EP - 19634 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-64863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Michaelis, Matthias A1 - Prinz, Carsten A1 - Würth, Christian T1 - Time-resolved luminescence spectroscopy for monitoring the stability and dissolution behaviour of upconverting nanocrystals with different surface coatings† N2 - We demonstrate the potential of time-resolved luminescence spectroscopy for the straightforward assessment and in situ monitoring of the stability of upconversion nanocrystals (UCNPs). Therefore, we prepared hexagonal NaYF4:Yb3+,Er3+ UCNPs with various coatings with a focus on phosphonate ligands of different valency, using different ligand exchange procedures, and studied their dissolution behaviour in phosphate-buffered saline (PBS) dispersions at 20 °C and 37 °C with various analytical methods. The amount of the released UCNPs constituting fluoride ions was quantified by potentiometry using a Fluoride ion-sensitive electrode and particle disintegration was confirmed by transmission electron microscopy studies of the differently aged UCNPs. In parallel, the luminescence features of the UCNPs were measured with special emphasis on the lifetime of the sensitizer emission to demonstrate its suitability as Screening parameter for UCNP stability and changes in particle composition. The excellent correlation between the changes in luminescence lifetime and fluoride concentration highlights the potential of our luminescence lifetime method for UCNP stability screening and thereby indirect monitoring of the release of potentially hazardous fluoride ions during uptake and dissolution in biological systems. Additionally, the developed in situ optical method was used to distinguish the dissolution dynamics of differently sized and differently coated UCNPs. KW - Fluorescence KW - Lifetime KW - Method KW - Quantification KW - Stability KW - Coating KW - Surface chemistry KW - Lanthanide KW - Fluoride KW - Electrochemistry KW - ICP-OES KW - Upconversion KW - Nano KW - Particle KW - Aging KW - Quality assurance KW - TEM PY - 2020 DO - https://doi.org/10.1039/d0nr02931a VL - 12 IS - 23 SP - 12589 EP - 12601 PB - Royal Society od Chemistry AN - OPUS4-52088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simons, C. A1 - Mans, C. A1 - Hanning, S. A1 - Janßen, A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Ostermann, Markus A1 - Michaelis, Matthias A1 - Wienold, Julia A1 - Alber, D. A1 - Kreyenschmidt, M. T1 - Study on microscopic homogeneity of polymeric candidate reference materials BAM H001-BAM H010 by means of synchrotron µ-XRF and LA-ICP-MS N2 - In this study the microscopic homogeneity of the newly developed plastic reference materials BAM H001-BAM H010 was investigated. The materials consist of an acrylonitryle-butadien-styrene terpolymer, doped with different amounts of the elements Br, Cd, Cr, Hg and Pb. For the quantitative determination of the degree of homogeneity, a procedure proposed by Kempenaers et al. (Fresenius J. Anal. Chem., 2001, 369, 733-737) was used. On every sample an extensive number of different points were analyzed and standard deviation for every element mentioned above was used to calculate a minimal sampling mass that is necessary to reach a certain level of uncertainty caused by inhomogeneity (mmin,5%). The experiments were taken out with synchrotron µ-XRF (SR µ-XRF) at BESSYII in Berlin and by laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS). The calculated values for mmin,5% of both techniques showed comparable results for all elements. It could be shown that the materials are suitable for calibration of micro analytic techniques if at least 64 µg are used. KW - XRF KW - LA-ICP-MS KW - RoHS KW - CRM PY - 2010 DO - https://doi.org/10.1039/b917008a SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 40 EP - 43 PB - Royal Society of Chemistry CY - London AN - OPUS4-20938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -