TY - CONF A1 - Agudo Jácome, Leonardo A1 - Pöthkow, K. A1 - Paetsch, O. A1 - Hege, H.-C. T1 - 3D Reconstruction, Visualization and Quantification of Dislocations from TEM Stereo-Pairs N2 - Dislocations, as carriers of plastic deformation, affect important properties in technical materials, e. g., plasticity. The realistic description of plastic deformation caused by dislocations demands the representative measurement of their features, e.g., line direction, slip plane, Burgers vector and density. Bulk deformation of structural and functional alloys requires reliable data from large regions. The filiform nature of dislocations interacting with complex microstructures additionally demands observation and analysis techniques that allow resolving the details of their interactions in space. The use of electron tomography for this purpose is bound to difficult and time consuming experimental setups, which are not always applicable to any material. In this contribution a new tool is presented, which enables the three-dimensional reconstruction, visualization and quantification of dislocation densities and directions from manual tracing of scanning transmission electron microscopy (STEM) stereo-pairs. Examples are shown from samples of a creep-deformed monocrystalline Ni-base superalloy. T2 - 3D Materials Science 2016 CY - St. Charles, Illinois, USA DA - 10.07.2016 KW - Dislocation KW - Scanning Transmission Electron Microscopy KW - 3D KW - Quantification KW - Superalloy PY - 2016 AN - OPUS4-42173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oberleitner, Lidia A1 - Garbe, L.-A. A1 - Dahmen-Levison, Ursula A1 - Schneider, Rudolf T1 - Improved strategies for selection and characterization of new monoclonal anticarbamazepine antibodies during the screening process using feces and fluorescence polarization immunoassay JF - Analytical Methods N2 - Immunoassays are suitable tools for high-throughput screenings. The prerequisite for accurate determinations by these methods is the selection of an excellent antibody. The production and selection of monoclonal antibodies is usually a tedious process. In this study, new strategies for improving antibody production and characterization were applied. This includes the monitoring of the immunization progress in mice through antibodies extracted from feces, which allows a time-resolved and animal-friendly monitoring of the immune response. Additionally, fluorescence polarization immunoassay (FPIA) could be successfully applied for fast and easy examination of cell culture supernatants and the investigation of antibody/antigen interactions including kinetics and fluorescence properties. These methods simplify the selection of the optimal antibody. As a target analyte, carbamazepine was chosen. This is a widely used antiepileptic drug which also frequently occurs in the environment. The new antibody enables CBZ determination in the concentration range 0.66–110 µg L-1 within 10 min using a high-throughput microtiter plate-based FPIA, and between 1.4 and 79 µg L-1 within 5 min applying an automated cuvette-based FPIA instrument, and from 0.05–36 µg L-1 using ELISA. The measurements were performed at a non-equilibrium state which improved the sensitivity and selectivity of the assays. Due to low cross-reactivity especially towards the main CBZ metabolite and other pharmaceuticals (<1%), this antibody gives the opportunity for application in medical and environmental analyses. KW - Antikörper KW - Emerging Pollutants KW - Schadstoffe KW - Monoklonal KW - Pharmazeutika KW - Arzneistoffe KW - Assay KW - Pesticide parathion-methyl KW - Waste-water KW - Samples KW - Pharmaceuticals KW - Quantification PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-392473 DO - https://doi.org/10.1039/c6ay01968d SN - 1759-9660 VL - 8 SP - 6883 EP - 6894 PB - Royal Society of Chemistry CY - London AN - OPUS4-39247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moser, Marko A1 - Schneider, Ralf A1 - Behnke, Thomas A1 - Schneider, Thomas A1 - Falkenhagen, Jana A1 - Resch-Genger, Ute T1 - Ellman’s and aldrithiol assay as versatile and complementary tools for the quantification of thiol groups and ligands on nanomaterials JF - Analytical Chemistry N2 - Simple, fast, and versatile methods for the quantification of thiol groups are of considerable interest not only for protein analysis but also for the characterization of the surface chemistry of nanomaterials stabilized with thiol ligands or bearing thiol groups for the subsequent (bio-) functionalization via maleimide−thiol chemistry. Here, we compare two simple colorimetric assays, the widely used Ellman’s assay performed at alkaline pH and the aldrithiol assay executed at acidic and neutral pH, with respect to their potential for the quantification of thiol groups and thiol ligands on different types of nanoparticles like polystyrene nanoparticles, semiconductor nanocrystals (SC NC), and noble metal particles, and we derive criteria for their use. In order to assess the underlying reaction mechanisms and to obtain stoichiometry factors mandatory for reliable thiol quantification, both methods were studied photometrically and with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), thereby demonstrating the influence of different thiols on the reaction mechanism. Our results underline the suitability of both methods for the quantification of directly accessible thiol groups or ligands on the surface of 2D- and 3D-supports, here exemplarily polystyrene nanoparticles. Moreover, we could derive strategies for the use of these simple assays for the determination of masked (i.e., not directly accessible) thiol groups like disulfides such as lipoic acid and thiol stabilizing ligands coordinatively bound to Cd and/or Hg surface atoms of II/VI and ternary SC NC and to gold and silver nanoparticles. KW - Nanoparticles KW - Ligands KW - Ellman KW - Aldrithiol KW - Quantification PY - 2016 DO - https://doi.org/10.1021/acs.analchem.6b01798 SN - 0003-2700 SN - 1520-6882 VL - 88 IS - 17 SP - 8624 EP - 8631 PB - ACS Publications CY - Washington AN - OPUS4-37561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Behnke, Thomas A1 - Moser, Marko A1 - Quevedo, Pablo A1 - Nirmalananthan-Budau, Nithiya A1 - Weigert, Florian A1 - Würth, Christian A1 - Hoffmann, Katrin A1 - Ermilov, Eugeny A1 - Pauli, Jutta T1 - Simple methods, validation concepts, and reference materials for the characterization of functional nanomaterials and microparticles N2 - The surface chemistry / functionalization of nanomaterials and microparticles largely controls the stability of these materials as well as their solubility and subsequent biofunctionalization and their interactions with biological systems. Moreover, in the case of some nanomaterials like semiconductor quantum dots or lanthanide-based upconversion nanocrystals, the ligand shell strongly affects their optical properties, e.g., via passivation of surface states and traps that favor luminescence quenching or the protection of surface atoms from quenching water molecules. This renders analytical methods for the quantification of surface groups like functionalities very important. Targets of broad interest are here amino, carboxyl, alkine and maleimide groups used for common bioconjugation reactions and typical ligands like thiols and polyethylene glycol (PEG) molecules of varying length, used for the tuning of material hydrophilicity and biocompatibility, minimization of unspecific interactions, prevention of biofouling, and enhancement of blood circulation times as well as surface-bound biomolecules like streptavidin or other biomolecules relevant e.g., for diagnostic assays. Here, we focus on simple optical methods relying on standard laboratory instrumentation, validated by method comparison and/or mass balances and present examples for their use for the characterization of different types of nanomaterials and microparticles. T2 - Innovationsforum Senftenberg CY - Senftenberg, Germany DA - 01.06.2016 KW - Surface chemistry KW - Functional group analysis KW - Thiol assay KW - Fluorescence KW - Nanomaterial KW - Nanoparticle KW - PEG KW - Ligand KW - Semiconductor quantum dot KW - Quantum yield KW - Quantification KW - Method validation KW - Integrating sphere spectroscopy KW - Fluorescence standard PY - 2016 N1 - Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. AN - OPUS4-37111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Applications and challenges of luminescence-based detection methods in the life and material sciences N2 - Luminescence-based detection methods, ranging from fluorescence spectroscopy for photophysical and mechanistic studies over sensing applications, chromatographic separation techniques and the microarray technology with fluorescence detection to fluorescence microscopy, flow cytometry, single molecule spectroscopy, and molecular imaging to integrating sphere spectroscopy, are among the most widely used methods in the life and material sciences. This is due to e.g., their unique sensitivity enabling the detection of single molecules, potential for multiplexing, ease of combination with spatial resolution, and suitability for remote sensing. Many of these advantages are closely linked to the choice of suitable molecular and nanoscale fluorescent reporters, typically required for signal generation. This includes organic dyes without and with sensor function, fluorophore-encoded polymeric and silica nanoparticles as well as nanocrystalline systems like semiconductor quantum dots and upconversion phosphors, emitting in the visible (vis), near-infrared (NIR), and IR (infrared). Current challenges present the environment sensitivity of most fluorophores, rendering fluorescence spectra, measured intensities/fluorescence quantum yields, and fluorescence decay kinetics matrix-dependent, and instrument-specific distortions of measured fluorescence signals that need to be considered for quantification and comparability of data, particularly fluorescence spectra. Here, current applications of luminescence-based methods and different types of reporters will be presented. In this context, suitable spectroscopic tools for the characteri-zation of the optical properties of fluorescent reporters and fluorophore-encoded microparticles, analytical tools for the determination of the surface chemistry of different types of particles, and different multiplexing strategies will be discussed. T2 - 9th Meeting of Engineering of Functional Interfaces CY - Wildau,Germany DA - 03.07.2016 KW - Fluorescence KW - Multiplexing KW - Lifetime KW - Nanomaterial KW - Nanoparticle KW - PEG KW - Ligand KW - Semiconductor quantum dot KW - Quantum yield KW - Quantification KW - Upconversion nanoparticle KW - Integrating sphere spectroscopy KW - NIR KW - IR KW - Fluorescence standard KW - Calibration PY - 2016 AN - OPUS4-37112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhiem, S. A1 - Barthel, Anne-Kathrin A1 - Meyer-Plath, A. A1 - Hennig, M. P. A1 - Wachtendorf, Volker A1 - Sturm, Heinz A1 - Schäffer, A. A1 - Maes, H. M. T1 - Release of 14C-labelled carbon nanotubes from polycarbonate composites JF - Environmental Pollution N2 - Waste disposal of carbon nanotube (CNT) containing products is expected to be the most important pathway for release of CNTs into the environment. In the present work, the use of radiolabelled CNTs (14C-CNT) for polycarbonate polymer nanocomposites with 1 wt% 14C-CNT content allowed for the first time to quantify and differentiate the CNT release according to the type of impact along the materials' ageing history. After an initial exposure of the nanocomposite by solar-like irradiation, further environmental impacts were applied to composite material. They aimed at mimicking disposal site conditions that may induce further ageing effects and CNT release. This study included shaking in water, rapid temperature changes, soaking in humic acid solution as well as waste water effluent, and, finally, gentle mechanical abrasion. All ageing impacts were applied sequentially, both on pristine (control) and on solar-irradiated nanocomposites. All experiments were accompanied by absolute quantification of radioactive release as well as chemical and morphological analyses of the nanocomposite surfaces using infra-red (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The morphological analysis showed that spectral irradiation can uncover CNT networks on the outer nanocomposite surface layers by polymer degradation. After having subjected the solar-irradiated nanocomposite to all studied disposal site effect, the total radioactive release was quantified to amount to 64 mg CNT/m2, whereas only 0.8 mg CNT/m2 were found for the un-irradiated control sample. Solar degradation of polymers was thus found to significantly increase the propensity of the studied polymer nanocomposites to release CNTs during ageing effects at the product's end-of-life typical for disposal sites. KW - Weathering KW - Carbon nanotubes KW - Nanocomposites KW - Release KW - Quantification PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0269749116303748 DO - https://doi.org/10.1016/j.envpol.2016.04.098 SN - 0269-7491 VL - 215 IS - August SP - 356 EP - 365 PB - Elsevier Ltd. CY - Paris AN - OPUS4-36899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharlach, C. A1 - Müller, Larissa A1 - Wagner, S. A1 - Kobayashi, Y. A1 - Kratz, H. A1 - Ebert, M. A1 - Jakubowski, Norbert A1 - Schellenberger, E. T1 - LA-ICP-MS allows quantitative microscopy of europium-doped iron oxide nanoparticles and is a possible alternative to ambiguous Prussian blue iron staining JF - Journal of Biomedical Nanotechnology N2 - The development of iron oxide nanoparticles for biomedical applications requires accurate histological evaluation. Prussian blue iron staining is widely used but may be unspecific when tissues contain substantial endogenous iron. Here we tested whether microscopy by laser ablation coupled to inductively coupled plasma mass spectrometry (LA-ICP-MS) is sensitive enough to analyze accumulation of very small iron oxide particles (VSOP) doped with europium in tissue sections. KW - Atherosclerotic plaques KW - LA-ICP-MS microscopy KW - Quantification KW - Element microscopy KW - Histology PY - 2016 DO - https://doi.org/10.1166/jbn.2016.2230 SN - 1550-7033 SN - 1550-7041 VL - 12 IS - 5 SP - 1001 EP - 1010 AN - OPUS4-36189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfeifer, Jens A1 - Richter, Silke A1 - Kipphardt, Heinrich T1 - RSFs for nickel matrix using doped pressed powder samples as needed for fast flow glow discharge mass spectrometry (GD-MS) N2 - Direct current (DC) fast flow glow discharge mass spectrometry is an important and versatile tool for multielemental trace analysis of conductive solid materials down to the µg/kg level. Special benefits are minimum demands on sample preparation, avoiding losses and contamination, and only short analysis time. For fast flow GD sources, the quantification strategy based on relative standard sensitivity factors (Standard RSFs) which are independent of matrix is not sufficiently satisfying regarding accuracy for each matrix and element [1]. Therefore matrix-matched calibration samples (MMCS) are required to achieve reliable quantification. In fact, the list of existing certified reference materials (CRM) appropri-ate for calibration in trace analysis is rather short. Convenient synthesis of homogeneous MMCS, as e.g. easily obtained in liquid sampling spectrometry, can facilitate the application of fast flow GD-MS for quantification of impurities in a variety of matrices. Pressing of metal powders for the preparation of MMCS for GD-MS was suggested earlier [2], the method was further modified by use of analyte solutions for doping of rather pure metal powders such as Cu and Zn [3], but has not yet been applied Ni matrix. In the present work we describe the determination of matrix-dependent relative sensitivity factors (RSFs) for Mg, Al, Cr, Mn, Fe, Co, Cu, Zn, Ag, Cd, Tl, Pb and Bi in pure Ni by using the liquid doping approach for the preparation of synthetic pressed Ni-powder samples. A four point-calibration was used applying the fast flow glow discharge mass spectrometer, Element GD (Thermo Fisher). The determined RSF were verified against suitable CRM and compared with the standard RSF given by the supplier of the instrument. The obtained results demonstrate a satisfying Agreement with the certified values of the CRM and a significant improvement for the quantification of most of the determined elements in comparison with standard RSF. T2 - International glow discharge spectroscopy symposium CY - Liverpool, UK DA - 18.04.2016 KW - GD-MS KW - Glow discharge KW - Nickel RSF KW - Calibration KW - Quantification PY - 2016 AN - OPUS4-35818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lazik, D. A1 - Ebert, S. A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias T1 - Characteristic length measurement of a subsurface gas anomaly - A monitoring approach for heterogeneous flow path distributions JF - International Journal of Greenhouse Gas Control N2 - Geogenic gases from natural sources, carbon dioxide (CO2) from a geological repository (carbon capture and storage - CCS) or a leaking gas pipeline can present serious risks in industrial and urban areas. To extend the lead time for risk treatment in such critical regions, reliable detection of gases within the shallow subsurface is required to observe critical gas accumulations before degassing into the atmosphere. A near real-time monitoring approach is introduced to determine the volumetric expansion of a leakinggas in the subsurface. Considering the pressure relaxation with the ambient air pressure, the approach enables the forecasting of the final size of a pressurized gas body in terms of characteristic lengths. According to theoretical basics, such a characteristic length, which enables us to perform a gas (safety) measurement based on a purely geometrical measure, behaves independently of subsurface properties,i.e., it enables a reliable quantification of the escaping gas irrespective of its heterogeneous or changingflow path distribution. A field test for a 10 l/min pinhole leakage injected into a 10 m long, 0.4 m wide, 0.95 m deep soil-filled trench that was equipped with linear sensors shows the lateral-vertical volumetric gas expansion along these sensors, and demonstrates the applicability of the characteristic length approach. KW - Monitoring KW - Carbon capture and storage KW - Leakage KW - Quantification KW - Subsurface KW - CO2 PY - 2016 DO - https://doi.org/10.1016/j.ijggc.2016.02.008 SN - 1750-5836 VL - 2016 IS - 47 SP - 330 EP - 341 PB - Elsevier B.V. AN - OPUS4-35425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittler, Katrin A1 - Hurtaud-Pessel, D. A1 - Maul, Ronald A1 - Kolrep, F. A1 - Fessard, V. T1 - In vitro metabolism of the cyanotoxin cylindrospermopsin in HepaRG cells and liver tissue fractions JF - Toxicon N2 - No evidence for phase I metabolites of the cyanotoxin cylindrospermopsin (CYN) was given using HepaRG cells and different liver tissue fractions when studying metabolic conversion. Although the application of ketoconazole, a CYP3A4 inhibitor, led to a decreased cytotoxicity of CYN, no metabolites were detected applying high resolution mass spectrometry. Quantification of non-modified CYN led to recovery rates of almost 100%. Consequently, reduction of CYN toxicity in the presence of metabolism inhibiting agents must be attributed to alternative pathways. KW - Cylindrospermopsin KW - Metabolism KW - Liver tissue fractions KW - HepaRG cells KW - LC-HRMS KW - Quantification KW - Cyanotoxin PY - 2016 DO - https://doi.org/10.1016/j.toxicon.2015.11.007 SN - 0041-0101 SN - 1879-3150 VL - 110 SP - 47 EP - 50 PB - Elsevier CY - Oxford [u.a.] AN - OPUS4-35222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -