TY - CONF A1 - Noordmann, J. A1 - Richter, Silke A1 - Kipphardt, Heinrich A1 - Kaltenbach, A. A1 - Görlitz, V. A1 - Rienitz, O. T1 - Gravimetric preparation and characterization of a primary reference solution of molybdenum N2 - Gravimetrically prepared mono-elemental reference solutions having a well-known mass fraction of approximately 1 g/kg define the very basis of virtually all measurements in inorganic analysis. Serving as the starting materials of all standard/calibration solutions, they link virtually all measurements of inorganic analytes to the purity of the solid materials they were prepared from. In case these solid materials are characterized comprehensively with respect to their purity, this link also establishes direct metrological traceability to The International System of Unit. Within the framework of the European Metrology Research Programme (EMRP), in the Joint Research Project called SIB09 Primary standards for challenging elements, a reference solution of molybdenum was prepared directly from the respective metal with a relative expanded uncertainty associated with the mass fraction of Urel(w) < 0.05 %. A highly accurate and precise ICP OES and MC-ICP-MS method was developed to assist with the preparation and as a dissemination tool. T2 - ANACON CY - Graz, Austria DA - 23.03.2015 KW - Metrology KW - Primary standards KW - Mo PY - 2015 AN - OPUS4-38038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roebben, G. A1 - Kestens, V. A1 - Varga, Z. A1 - Charoud-Got, J. A1 - Ramaye, Y. A1 - Gollwitzer, Christian A1 - Bartczak, D. A1 - Geißler, Daniel A1 - Noble, J.E. A1 - Mazoua, S. A1 - Meeus, N. A1 - Corbisier, P. A1 - Palmai, M. A1 - Mihály, J. A1 - Krumrey, M. A1 - Davies, J. A1 - Resch-Genger, Ute A1 - Kumarswami, N. A1 - Minelli, C. A1 - Sikora, A. A1 - Goenaga-Infante, H. T1 - Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case N2 - This paper describes the production and characteristics of the nanoparticle test materials prepared for common use in the collaborative research project NanoChOp (Chemical and optical characterization of nanomaterials in biological systems), in casu suspensions of silica nanoparticles and CdSe/CdS/ZnS quantum dots (QDs). This paper is the first to illustrate how to assess whether nanoparticle test materials meet the requirements of a "reference material" (ISO Guide 30, 2015) or rather those of the recently defined category of "representative test material (RTM)" (ISO/TS 16195, 2013). The NanoChOp test materials were investigated with small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and centrifugal liquid sedimentation (CLS) to establish whether they complied with the required monomodal particle size distribution. The presence of impurities, aggregates, agglomerates, and viable microorganisms in the suspensions was investigated with DLS, CLS, optical and electron microscopy and via plating on nutrient agar. Suitability of surface functionalization was investigated with attenuated total reflection Fourier transform infrared spectrometry (ATR-FTIR) and via the capacity of the nanoparticles to be fluorescently labeled or to bind antibodies. Between-unit homogeneity and stability were investigated in terms of particle size and zeta potential. This paper shows that only based on the outcome of a detailed characterization process one can raise the status of a test material to RTM or reference material, and how this status depends on its intended use. KW - Nanoparticle KW - Materials characterization KW - Reference material KW - Analytical quality assurance KW - Metrology PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-349644 DO - https://doi.org/10.3389/fchem.2015.00056 SN - 2296-2646 VL - 3 SP - Article 56, 1 EP - 16 PB - Frontiers Media CY - Lausanne AN - OPUS4-34964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maiwald, Michael A1 - Meyer, Klas A1 - Zientek, Nicolai A1 - Paul, Andrea T1 - qNMR forever – reference material metrology at high pressures and high purities N2 - Due to recent advances in technical developments of NMR instruments such as acquisition electronics and probe design, detection limits of components in liquid mixtures were improved into the lower ppm range (approx. 5–10 ppm amount of substance). This showed that modern NMR equipment is also suitable for the observation of hydrocarbon samples in the expanded fluid phase or gas phase. Since Quantitative NMR spectroscopy (qNMR) is a direct ratio method of analysis without the need of calibration it was used to determine impurities in appropriate liquid and liquefied hydrocarbon isomers up to C6, which are used for preparation of primary gas standards, e.g., natural gas or exhaust gas standards. At the same time it is possible to yield structural information with a minimum of sample preparation. Thus, cross contaminations between different isomers of the observed hydrocarbons and their (NMR-active) impurities can be identified and quantified. In general, most quantitative organic chemical measurements rely on the availability of highly purified compounds to act as calibration standards. The traceability and providence of these standards is an essential component of any measurement uncertainty budget and provides the final link of the result to the units of measurement, ideally the SI. The more recent increase in the use of qNMR for the direct assessment of chemical purity however can potentially improve the traceability and reduce the uncertainty of the measured chemical purity at a reduced cost and with less material. For example the method has beneficially been used by National Measurement institutes for recent CCQM comparisons including the CCQM–K55 series of purity studies. Traditional ‘indirect’ methods of purity analysis require that all impurities are identified and quantified, leading to a minimum of 4 individual analytical methods (organic impurities, water, solvents, inorganic residue). These multiple technique approaches measure an array of different chemical impurities normally present in purified organic chemical compounds. As many analytical methodologies have compound-specific response factors, the accuracy and traceability of the purity assessment is dependent on the availability of reference materials of the impurities being available. qNMR provides the most universally applicable form of direct purity determination without need for reference materials of impurities or the calculation of response factors but only exhibiting suitable NMR properties. The development of CRMs addressing qNMR specific measurement issues will give analysts compounds ideally suited for the analytical method and also provide full characterisation of qNMR related parameters to enable more realistic uncertainty budgets. These materials will give users the tools to exploit qNMR more easily and enable them to speed up analytical method development and reduce the time and financial burden of multiple analytical testing. T2 - 3rd Practical Application of NMR in Industry Conference (PANIC) 2015 CY - La Jolla, CA, USA DA - 09.02.2015 KW - qNMR KW - Quantitative NMR-Spektroskopie KW - Reference Material KW - Metrology PY - 2015 AN - OPUS4-36144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maiwald, Michael A1 - Zientek, Nicolai A1 - Meyer, Klas A1 - Kern, Simon A1 - Paul, Andrea T1 - Quantitative and online NMR Spectroscopy at BAM N2 - Online NMR spectroscopy, Determination of impurities of fluids, NMR process Monitoring, purity assessment T2 - NMR-Kolloquium Buchs CY - Buchs, Switzerland DA - 29.05.2015 KW - qNMR KW - Quantitative NMR-Spektroskopie KW - Online NMR Spectroscopy KW - Reaction monitoring KW - Reference material KW - Metrology PY - 2015 AN - OPUS4-36143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -