TY - JOUR A1 - Pires, A. A1 - Almeida, Ângela A1 - Calisto, V. A1 - Schneider, Rudolf A1 - Esteves, V. I. A1 - Wrona, F. J. A1 - Soares, A. M. V. M. A1 - Figueira, E. A1 - Freitas, R. T1 - Long-term exposure of polychaetes to caffeine: Biochemical alterations induced in Diopatra neapolitana and Arenicola marina N2 - In the last decade studies have reported the presence of several pharmaceutical drugs in aquatic environments worldwide and an increasing effort has been done to understand the impacts induced on wildlife. Among the most abundant drugs in the environment is caffeine, which has been reported as an effective chemical anthropogenic marker. However, as for the majority of pharmaceuticals, scarce information is available on the adverse effects of caffeine on marine benthic organisms, namely polychaetes which are the most abundant group of organisms in several aquatic ecossystems. Thus, the present study aimed to evaluate the biochemical alterations induced by environmentally relevant concentrations of caffeine on the polychaete species Diopatra neapolitana and Arenicola marina. The results obtained demonstrated that after 28 days exposure oxidative stress was induced in both species, especially noticed in A. marina, resulting from the incapacity of antioxidant and biotransformation enzymes to prevent cells from lipid peroxidation. The present study further revealed that D. neapolitana used glycogen and proteins as energy to develop defense mechanisms while in A. marina these reserves were maintained independently on the exposure concentration, reinforcing the low capacity of this species to fight against oxidative stress. KW - Invertebrates KW - Pharmaceuticals KW - Oxidative stress biomarkers KW - Energy reserves PY - 2016 DO - https://doi.org/10.1016/j.envpol.2016.04.031 VL - 2016 IS - 214 SP - 456 EP - 463 PB - Elsevier Ltd. AN - OPUS4-38505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cruz, D. A1 - Almeida, Ângela A1 - Calisto, V. A1 - Esteves, V. I. A1 - Schneider, Rudolf A1 - Wrona, F. J. A1 - Soares, A. M. V. M. A1 - Figueira, E. A1 - Freitas, R. T1 - Caffeine impacts in the clam Ruditapes philippinarum: Alterations on energy reserves, metabolic activity and oxidative stress biomarkers N2 - Caffeine is known to be one of the most consumed psychoactive drugs. For this reason, caffeine is continuously released into the environment with potential impacts on inhabiting organisms. The current study evaluated the biochemical alterations induced in the clam species Ruditapes philippinarum after exposure for 28 days to caffeine (0.5, 3.0 and 18.0 mg/L). The results obtained showed that, with the increasing caffeine concentrations, an increase in clams defense mechanisms (such as antioxidant and biotransformation enzymes activity) was induced which was accompanied by an increase in protein content. Nevertheless, although an increase on defense mechanisms was observed, clams were not able to prevent cells from lipid peroxidation that increased with the increase of caffeine concentration. Furthermore, with the increase of exposure concentrations, clams increased their metabolic activity (measured by electron transport activity), reducing their energy reserves (glycogen content), to fight against oxidative stress. Overall, the present study demonstrated that caffeine may impact bivalves, even at environmentally relevant concentrations, inducing oxidative stress in organisms. The present study is an important contribution to address knowledge gaps regarding the impacts of long-term exposures to pharmaceuticals since most of the studies assessed the effects after acute exposures, most of them up to 96 h. KW - Bivalves KW - Oxidative stress KW - Pharmaceuticals KW - Long-term exposure KW - Environmentally relevant concentrations PY - 2016 DO - https://doi.org/10.1016/j.chemosphere.2016.06.068 VL - 2016 IS - 160 SP - 95 EP - 103 PB - Elsevier Ltd. AN - OPUS4-38508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Anja A1 - Lippitz, Andreas A1 - Radnik, Jörg A1 - Dörfel, Ilona A1 - Sparnacci, K. A1 - Ritter, B. A1 - Kemnitz, E. A1 - Unger, Wolfgang T1 - Quantitative chemichal depth-profiling by synchrotron-radiation-XPS N2 - Synchrotron-radiation enables the adjustment of the XPS information depth and, thus, the visualization of depth profiles of the elemental composition within the first 10 nm of a surface. This project deals with the analysis of core-shell nanoparticles. It constitutes first steps towards a valid methodology for studying the surface chemistry of nanoparticles in a quantitative and accurate manner. T2 - Eighth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 07.12.2016 KW - XPS KW - Synchrotron KW - Depth-profiling KW - Core@Shell Nanoparticles PY - 2016 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. AN - OPUS4-38782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Janine A1 - Fettig, I. A1 - Philipp, Rosemarie A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Fisicaro, P. A1 - Alasonati, E. T1 - Determination of tributyltin in whole water matrices under the European water framework directive N2 - Monitoring of water quality is important to control water pollution. Contamination of the aquatic systemhas a large effect on human health and the environment. Under the European Water Framework Directive(WFD) 2000/60/EC and the related directive on environmental quality standards (EQS) in the field of waterpolicy 2008/105/EC, the need for sensitive reference methods was highlighted. Since tributyltin (TBT) isone of the WFD listed priority substances a method was developed which is capable to qualify and quantifythe pollutant at the required low WFD EQS of 0.2 ng L⁻¹ in whole water bodies, i.e. in non-filtered watersamples with dissolved organic carbon and suspended particulate matter. Therefore special attention waspaid on the interaction of TBT with the suspended particulate matter and humic substances to obtain acomplete representation of the pollution in surface waters. Different water samples were investigatedvarying the content of organic dissolved and suspended matter. Quantification was performed usingspecies-specific isotope dilution (SSID) and gas chromatography with inductively coupled plasma massspectrometry (GC-ICP-MS). Different sample treatment strategies were evaluated and compared. Theprocess of internal standard addition was investigated and optimized, hence the equilibrium betweeninternal standards and matrix is of primary importance to perform accurate SSID. Samples spiked at EQSlevel were analyzed with a recovery between 95 and 105 %. Additionally real surface water samples wereinvestigated and the TBT concentration for the whole water body was determined and compared withconventional routine analysis method. KW - Tributyltin (TBT) KW - Environmental quality standard (EQS) KW - Isotope dilution KW - Humic acid KW - Surface water KW - Suspended particulate matter PY - 2016 DO - https://doi.org/10.1016/j.chroma.2016.06.068 SN - 0021-9673 VL - 1459 SP - 112 EP - 119 AN - OPUS4-36930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kern, Simon A1 - Michalik-Onichimowska, Aleksandra A1 - Riedel, Jens A1 - Panne, Ulrich A1 - King, R. A1 - Maiwald, Michael T1 - “Click” analytics for “click” chemistry – a simple method for calibration-free evaluation of online NMR spectra N2 - Currently research in chemical manufacturing moves towards flexible plug-and-play approaches focusing on modular plants, capable of producing small scales on-demand with short down-times between individual cam-paigns. This approach allows for efficient use of hardware, a faster optimization of the process conditions, and thus, an accelerated introduction of new products to the market. Driven mostly by the search for chemical syntheses under biocompatible conditions, so-called “click” chemistry rapidly became a growing field of research. The re-sulting simple one-pot reactions are so far only scarcely accompanied by an adequate optimization via compara-bly straightforward and robust analysis techniques. Here we report on a fast and reliable calibration-free online high field NMR monitoring approach for technical mixtures. It combines a versatile fluidic system, continuous-flow measurement with a time interval of 20 s per spectrum, and a robust, automated algo-rithm to interpret the ob-tained data. All spectra were acquired using a 500 MHz NMR spectrometer (Varian) with a dual band flow probe having a 1/16 inch polymer tubing working as a flow cell. Single scan 1H spectra were recorded with an acquisition time of 5 s, relaxation delay of 15 s. T2 - 12. Kolloquium des Arbeitskreises Prozessanalytik CY - Berlin, Germany DA - 28.11.2016 KW - Online NMR KW - Online monitoring KW - “Click” chemistry PY - 2016 AN - OPUS4-38585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Krankenhagen, Rainer A1 - Weber, H. T1 - Thickness determination of semitransparent isolated solids using the flash method and an analytical model N2 - As groundwork for thickness determination of polymeric surface protection systems for concrete, we present a method for measuring the thickness of isolated semitransparent solids using pulse thermography both in Transmission and reflection geometry. Since standard models do not capture semitransparency, an advanced analytical model by Salazar et al. is applied. Physical material parameters are deduced by fitting experimental data from samples of well-known thickness. Using those, the thickness of samples of the material can be obtained by fitting, as demonstrated for different semitransparent polymer materials. T2 - QIRT 2016 CY - Gdańsk, Poland DA - 04.07.2016 KW - Analytical model KW - Concrete KW - Flash thermography KW - Semitransparency KW - Surface protection KW - Thermography KW - Thickness PY - 2016 DO - https://doi.org/10.21611/qirt.2016.001 SN - 2371-4085 VL - 2016 SP - 71 EP - 78 AN - OPUS4-37200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Krankenhagen, Rainer A1 - Bavendiek, F. T1 - Thickness determination of polymeric multilayer surface protection systems for concrete by means of pulse thermography N2 - So far, only destructive measurement techniques are available for thickness determination of polymer based surface protection systems for concrete surfaces. Pulse thermography appears to be well suited for non-destructive thickness evaluation in these systems. Here, we present first results of the development of a respective measurement and analysis procedure. Since surface protection systems consist of a number of layers, a model for the calculation of the surface temperature of a multi-layer structure on an infinite (concrete) substrate in pulse thermography setup was developed. It considers semitransparency of the upmost layer and thermal losses at the surface. It also supports the use of an arbitrary temporal shape of the heating pulse to properly describe the measurement conditions for different heat sources. First experimental results regarding the verification of the model are presented. Funding by the Federal Ministry for Economic Affairs and Energy is gratefully acknowledged. T2 - QNDE 2016 CY - Atlanta, GA, USA DA - 17.07.2016 KW - Thermography KW - Analytical model KW - Surface protection KW - Concrete KW - Semitransparency KW - Thickness PY - 2016 AN - OPUS4-36984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Krankenhagen, Rainer A1 - Weber, H. T1 - Thickness determination of semitransparent isolated solids using the flash method and an analytical model N2 - As groundwork for thickness determination of polymeric surface protection systems for concrete, we present a method for measuring the thickness of isolated semitransparent solids using pulse thermography both in transmission and reflection configuration. An advanced analytical model by Salazar et al. capturing semitransparency is applied. After calibration with samples of well-known thickness, the unknown thickness of samples of the same material can be obtained by fitting. T2 - QIRT 2016 CY - Gdansk, Poland DA - 04.07.2016 KW - Thermography KW - Analytical model KW - Surface protection KW - Concrete KW - Semitransparency KW - Thickness KW - Flash thermography PY - 2016 AN - OPUS4-36983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sötebier, Carina A. A1 - Weidner, Steffen A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Bettmer, J. T1 - Separation and quantification of silver nanoparticles and silver ions using reversed phase high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry in combination with isotope dilution analysis N2 - A reversed phase high performance liquid chromatography coupled to an inductively coupled Plasma mass spectrometer (HPLC–ICP-MS) approach in combination with isotope dilution analysis (IDA) for the separation and parallel quantification of nanostructured and ionic silver (Ag) is presented. The main Focus of this work was the determination of the ionic Ag concentration. For a sufficient stabilization of the Ions without dissolving the nanoparticles (NPs), the eluent had to be initially optimized. The determined Ag ion concentration was in a good agreement with results obtained using ultrafiltration. Further, the mechanism of the NP separation in the HPLC column was investigated. Typical size exclusion effects were found by comparing results from columns with different pore sizes. Since the recovery rates decreased with increasing Ag NP size and large Ag NPs did not elute from the column, additional interactions of the particles with the stationary phase were assumed. Our results reveal that the presented method is not only applicable to Ag NPs, but also to gold and polystyrene NPs. Finally, IDA-HPLC-ICP-MS experiments in single particle mode were performed to determine the particle cut-off size. The comparison with conventional spICP-MS experiments resulted in a similar diameter and particle size distribution. KW - ICP-MS KW - Silver nanoparticles KW - Speciation KW - High performance liquid chromatography KW - Isotope dilution analysis PY - 2016 DO - https://doi.org/10.1016/j.chroma.2016.09.028 SN - 0021-9673 VL - 1468 SP - 102 EP - 108 AN - OPUS4-37652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nadejde, C. A1 - Neamtu, M. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Ababei, G. A1 - Panne, Ulrich T1 - Hybrid iron-based core-shell magnetic catalysts for fast degradation of bisphenol A in aqueous systems N2 - Three types of hybrid modified magnetite (Fe₃O₄) nanoparticles, functionalized with either chitosan, chitosan/iron (II) oxalate or chitosan/iron (III) citrate, were synthesized by chemical precipitation method. The obtained nanomaterials were characterized by energy dispersive X-ray spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller analysis, scanning and Transmission electron microscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometry. The prepared composites were further tested as magnetic catalysts for the removal of bisphenol A (BPA) in aqueous media. The kinetic Degradation experiments were performed at laboratory scale, while the best operational parameters for all three materials were established: 1.00 g L⁻¹ of catalyst, 10 mmol L⁻¹ H₂O₂, under simulated solar light irradiation. After 15 min of UVA irradiation under the experimental conditions mentioned above, it was possible to decompose up to 99% of the micropollutant over all catalysts. Fe₃O₄/chitosan/iron oxalate catalyst showed the highest and fastest catalytic activity in BPA removal. Catalytic wet peroxide oxidation of non-biodegradable micropollutants on such iron-based hybrid nanoparticles can be a suitable pre-treatment method for wastewater decontamination, as an environment-friendly simplified Approach for water clean-up. KW - Katalysator KW - Bisphenol A KW - Nano KW - Fenton KW - Magnetische Nanopartikel PY - 2016 DO - https://doi.org/10.1016/j.cej.2016.05.090 SN - 1385-8947 VL - 302 SP - 587 EP - 594 PB - Elsevier CY - Amsterdam AN - OPUS4-37126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mekonnen, Tessema Fenta A1 - Koch, Matthias A1 - Panne, Ulrich T1 - Metabolic transformation products of pesticides by electrochemical cell coupled to LC-MS (EC-LC-MS) N2 - Metabolic transformation products (TPs) of the insecticide chlorpyrifos (CPF), the new fungicide fluopyram (FLP) and the broad-spectrum herbicide, glyphosate (GLP), were studied by electrochemistry coupled to mass spectrometry (EC-MS) for the first time. Phase I metabolites of the three pesticides from rat liver in-vitro assay experiments were studied by LC-MS/MS and compared to electrochemically oxidized products from EC-MS. Known metabolites from S-oxidation, O-dealkylation and hydroxylation of the insecticide chlorpyrifos have been identified by EC-MS and simulated to in-vitro assays. Chlorpyrifos-oxon (CPF-oxon), diethylthiophosphate (DETP), 3,5,6-trichloropiridinol (TCP), diethylphosphate (DEP) and 2,3,5-trichloropyridine (TCPy) were the main EC oxidative TPs and in-vitro assay metabolites of CPF which was also reported by Choe et al.. Fluopyram was extensively converted to a number of electrochemical products including mono- and dihydroxylated derivatives and yet unidentified TPs. Rat liver microsomal assay experiments showed mainly hydroxylated metabolites of FLP which was also reported by the European Food Safety Agency (EFSA). Aminomethyl phosphonic acid (AMPA) was the main TP of glyphosate detected from both EC-MS analysis and in-vitro assay tests. A number of TPs of CPF, FLP and GLP have been identified by electrochemistry online mass spectrometry and compared to in-vitro assays. Using electrochemistry upfront MS enables fast and matrix free prediction of metabolic pathways, transformation products and/or fate of pesticides. Further studies will focus on structural characterization of detected compounds, phase II metabolites and investigation of real samples. T2 - 9th European Conference on Pesticides and Related Organic Micropollutants in the Environment: 15th Symposium on Chemistry and Fate of Modern Pesticides CY - Santiago de Compostela, Spain DA - 04.10.2016 KW - EC-MS KW - Pesticides KW - Transformation products (TPs) KW - Metabolites PY - 2016 AN - OPUS4-37707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lingott, Jana A1 - Lindner, Uwe A1 - Telgmann, Lena A1 - Esteban-Fernández, Diego A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry N2 - The uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). KW - Gadolinium-uptake KW - Speciation KW - HILIC KW - ICP-MS PY - 2016 DO - https://doi.org/10.1039/c5em00533g SN - 2050-7887 VL - 18 IS - 2 SP - 200 EP - 207 PB - Royal Society of Chemistry CY - Cambridge, UK AN - OPUS4-36281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert A1 - Müller, Larissa A1 - Traub, Heike A1 - Esteban-Fernández, Diego A1 - Panne, Ulrich A1 - Herrmann, Antje A1 - Schellenberger, E. A1 - Kneipp, J. T1 - Novel strategies for standardization and calibration in Laser Ablation ICP-MS N2 - Elemental imaging of biological samples (bio-imaging) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) provides spatially resolved information on element distribution (qualitative and quantitative) in thin sections of biological samples. By rastering with a laser across the sample, a two-dimensional image of the elemental distribution can be reconstructed that shows the relative intensities of the respective elements. However the method is hampered by a lack of internal standards and quantification concepts, which will be discussed in this lecture in more detail. In liquid analysis the internal standard is used for drift correction and calibration and thus it is required that the standard should have similar physical and chemical properties similar to the analyte element during the pneumatic nebulization process, the transport, ionization and transmission into the ICP-MS. In laser ablation it should correct additionally for differences in the ablation process by laser instabilities or changes of sample properties to compensate variations or drift effects during the LA process. T2 - SALSA Lecture CY - Berlin, Germany DA - 14.06.2016 KW - Standardization KW - Calibration KW - LA-ICP-MS PY - 2016 AN - OPUS4-37164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina A1 - Kutscher, D. J. A1 - Rottmann, L. A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Bettmer, J. T1 - Application of ICP-MS in the single particle mode and isotope dilution analysis on the example of silver nanoparticles N2 - Due to its simplicity, speed and ability to obtain a particle number size distribution, single particle ICP-MS (spICP-MS) has emerged as an important tool for the analysis of nanoparticles (NPs). However, when NPs are suspended in a complex, unknown solution, matrix effects can occur affecting the instrument’s sensitivity. As a result, an over- or underestimation of the particle size is possible. In this work, a proof-of-concept study of the combination of isotopic dilution analysis (IDA) and spICP-MS compensating for possible matrix effects is presented. As an example, an isotopically enriched 109Ag standard solution was added to silver NPs (Ag NP) suspensions. Different NP suspensions with mean particle diameters between 30 and 80 nm were chosen. The mixtures were analyzed using a quadrupole ICP-MS instrument. Both Ag isotopes (107Ag and 109Ag) were monitored during one experiment. The result show a good agreement with the diameters obtained using conventional spICP-MS. In a second step, the Ag NPs were suspended in a simulated seawater matrix. Using conventional spICP-MS, a great reduction in the signal intensities and consequently in the particle sizes, was monitored. The application of the IDA-spICP-MS approach on these samples was able to obtain similar diameters compared to the samples without matrix. T2 - Anwendertreffen Plasmaspektrometrie CY - Berlin, Germany DA - 22.02.2016 KW - Single particle ICP-MS KW - Silver nanoparticles KW - Isotope dilution analysis PY - 2016 AN - OPUS4-35627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina A1 - Bierkandt, Frank A1 - Bettmer, J. A1 - Rades, Steffi A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Characterization of Ag nanoparticles: limitation and advantages of field-flow fractionation N2 - Silver nanoparticles (Ag NPs) are widely used in consumer products due to their excellent antibacterial properties. Their broad application has led to a variety of recent regulation on their use and labelling. Thus, a highly specific analytical method for their characterization and quantification is needed. Due to their large separation range, field-flow fractionation (FFF) techniques are repeatedly applied for the analysis of NP. Limitations of FFF include quantification, sample loss and insufficient recovery rates. Another challenge can be non-ideal elution behavior of particles in complex and unknown matrices. The possible sources for sample losses of Ag NP have been studied using an asymmetric flow FFF (AF4) in combination with inductively coupled plasma mass spectrometry (ICP-MS). The influence of different parameters, for example the sample concentration, on the recovery rates and sample loss has been investigated. Using laser ablation ICP-MS, the Ag deposition on the membrane was located and quantified. Our results identified ionic silver as the main sources of sample loss. These results can be useful for further method improvement. However, when a Ag NP sample containing an unknown complex matrix is analyzed, FFF method optimization is challenging as the sample might show a shift in the retention times and lower recovery rates. In this case, ICP-MS experiment in the single particle mode (sp-ICP-MS) can be a useful addition to the FFF measurement. Here, upon assumption of spherical particles, the geometric diameters can be calculated. This fast and easy approach can be helpful in order to interpret the FFF fractograms and advice the FFF method optimization process. T2 - 18th International Symposium on Field- and Flow-Based Separations CY - Dresden, Germany DA - 22.05.2016 KW - Silver KW - Nanoparticles KW - Field-flow fractionation KW - ICP-MS PY - 2016 AN - OPUS4-36352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Antje Jutta A1 - Techritz, Sandra A1 - Panne, Ulrich A1 - Jakubowski, Norbert A1 - Haase, A. A1 - Müller, Larissa T1 - Simple and fast metal staining procedures for identification and characterization of single cells via laser ablation ICP-MS N2 - Biological systems exhibit a very high complexity, because they consist of various cell populations showing heterogenic characteristics. Therefore the individual analysis of single cells is important to understand cellular processes as well as their function in a cell system. Especially investigation in the question about what is biological variability and what is a substantial difference between two cells of the same type (which might lead to dysfunction or disease) is of high interest. Today improved spatial and temporal resolution enable the use of laser ablation inductively coupled mass spectrometry (LA-ICP-MS) for element microscopy of single cells. Next to the characterization of natural trace elements the introduction of artificial metal labels into cells is of high interest. Element labeling of cell compartments and/or proteins allows its simultaneous analysis and localization within a cell via element microscopy. Two fast and simple metal staining procedures of adherent cells for identification of single cells via LA-ICP-MS at sub micrometer resolution are presented. Two labeling reagents were selected which were already described in literature for applications around protein and cell analysis. An Iridium-intercalator is utilized to stain the cell nuclei whereas the whole cell is stained by maleimido-mono-amide-DOTA-complexes (mDOTA) loaded with lanthanide(III) isotope ions. The metal staining procedures allow the visualization of single cells by element microscopy independent of a superposition of analyte’s 2D element intensity profile with a prior taken bright field image of the sample. The applicability was shown on an actual question in nano-toxicology (the cellular uptake of nanoparticles). T2 - 25. ICP-MS Anwendertreffen CY - Siegen, Germany DA - 12.09.2016 KW - Metal staining procedures KW - Single cell analysis KW - Bioimaging PY - 2016 AN - OPUS4-37979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Antje A1 - Müller, Larissa A1 - Techritz, Sandra A1 - Jakubowski, Norbert A1 - Haase, A. A1 - Panne, Ulrich T1 - Simple and fast metal staining procedures for identification of single cells via Laser Ablation ICP-MS N2 - Biological systems exhibit a very high complexity, because they consist of various cell populations showing heterogenic characteristics. Therefore the individual analysis of single cells is important to understand cellular processes as well as their function in a cell system. Especially investigation in the question about what is biological variability and what is a substantial difference between two cells of the same type (which might lead to dysfunction or disease) is of high interest. Today improved spatial and temporal resolution enable the use of laser ablation inductively coupled mass spectrometry (LA-ICP-MS) for element microscopy of single cells. Next to the characterization of natural trace elements the introduction of artificial metal labels into cells is of high interest. Element labeling of cell compartments and/or proteins allows its simultaneous analysis and localization within a cell via element microscopy. Two fast and simple metal staining procedures of adherent cells for identification of single cells via LA-ICP-MS at sub micrometer resolution are presented. An Iridium-intercalator is utilized to stain the cell nuclei whereas the whole cell is stained by maleimido-mono-amide-DOTA-complexes (mDOTA) loaded with lanthanide(III) isotope ions. The metal staining procedures allow the visualization of single cells by element microscopy independent of a superposition of analyte’s 2D element intensity profile with a prior taken bright field image of the sample. T2 - EWLA 2016 CY - Ljubljana, Slovenia DA - 12.07.2016 KW - bioimaging KW - single cell analysis PY - 2016 AN - OPUS4-37077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bolz, Axel A1 - Panne, Ulrich A1 - Rurack, Knut A1 - Buurman, Merwe T1 - SERS microfluidic paper-based analytical devices N2 - The fast identification and quantification of analytes in the field of food safety or environmental analysis is difficult. Surface enhanced Raman scattering (SERS) is an analytical method which can be used simultaneously for the rapid identification and concentration determination of trace analytes,[1,2] usually covering a large dynamic range from nanomolar up to molar concentrations. The identification of the molecules is accomplished through the specific fingerprint of a molecule’s Raman spectrum. For facile and straightforward SERS measurements, we present here a combination of paper-based SERS test strips with microfluidic systems on paper as a microfluidic paper-based analytical device (μPAD). The SERS μPAD is thus principally suited for cheap, fast, non-destructive, label-free and portable detection of analytes. In this system basically, the use of the microfluidic structured paper increases the sensitivity and suppresses background signals of the SERS assay. Deposition of the SERS substrate on the test strips is simple and relies on an inkjet printer. For the optimization of the reproducibility and intensity of the SERS signal, we tested different nanoparticles, different numbers of print cycles and different paper types. The nanoparticle solutions used in the μPAD preparation were gold and silver nanoparticle solutions. The paper types were cellulose and glass fiber. SERS arrays were prepared by printing and compared to arrays prepared by spraying. The optimized μPAD was used for the identification and quantification of pure analyte solutions (e.g., adenine) and mixtures of compounds, the concentration series following Langmuir isotherms. Relevant analytes in the field of food safety are antibiotics and pesticides. We apply the SERS microfluidic paper-based analytical devices for the detection of antibiotics (enoxacin, enrofloxacin) and pesticides. T2 - Europtrode XIII CY - Graz, Austria DA - 20.03.2016 KW - SERS KW - Paper PY - 2016 AN - OPUS4-35702 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Michalik-Onichimowska, Aleksandra A1 - Riedel, Jens A1 - Panne, Ulrich A1 - Löhmannsröben, H.-G. T1 - Real time monitoring of photoreactions performed within levitated droplets by LA-DBD-MS N2 - The upscaling from small scale academic reactors to large industrial processes typically suffers from a large change in surface-to-volume ratio. A promising approach is the general avoidance of surfaces as in levitated droplet techniques. However, up to now, no mass spectrometric interface for online reaction monitoring in levitated droplets has been provided. As model reaction the photoinitiated thiol-ene coupling between N-boc cysteine methyl ester and allyl alcohol was studied. A droplet of 5 µL reactand solution was provisioned into an acoustic trap aligned lateral to the MS inlet. Contactless sampling by laser ablation (LA) is followed by dielectric barrier discharge (DBD) postionization. The latter is needed to address non polar reaction partners. T2 - 21st International Mass Spectrometry Conference CY - Toronto, Canada DA - 20.08.2016 KW - Monitoring of chemical reactions KW - Acoustic levitation KW - Laser ablation KW - Mass spectrometry PY - 2016 AN - OPUS4-37159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzweber, Markus A1 - Nietzold, Carolin A1 - Dietrich, Paul A1 - Lippitz, Andreas A1 - Kamalakumar, A. A1 - Ivanov-Pankov, S. A1 - Blanchard, V. A1 - Weigel, W. A1 - Panne, Ulrich A1 - Unger, Wolfgang T1 - Surface chemical characterization and shelf life studies of reference glycan microarrays using ToF-SIMS, XPS and fluorescence spectroscopy N2 - Covalent modification of surfaces with carbohydrates (glycans) is a prerequisite for a variety of glycomics-based biomedical applications, including functional biomaterials, glycan-arrays, and glycan-based biosensors. The chemistry of glycan immobilization plays an essential role in the bioavailability and function of surface bound carbohydrate moieties. For biomedical applications the stability over time (shelf life) of a glycan-array is a crucial factor. Basic requirements for the production of microarrays are first of all stable signals without any loss of quality. Therefore, the investigation of the shelf life for carbohydrate microarrays is an important part in the development of glycan-arrays. Motivated by the need of reliable quality control for glycan microarrays, we developed reference arrays using fluorescent model glycans. Since the long term stability of glycan microarrays is a crucial factor for their clinical application the shelf life at different storage conditions of glycan microarrays was studied in detail using the two model glycan compounds. Herein, we present a shelf life study of model glycan microarrays on epoxy modified glass surfaces over a period of 320 days. This was carried out using different analyzing techniques such as Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS) and Fluorescence Spectroscopy. To analyze and interpret the ToF-SIMS dataset the multivariate technique principal component analysis (PCA) was used. The dependence of the array´s shelf life upon storage conditions was specifically studied. T2 - SIMS Europe 2016 CY - Münster, Germany DA - 18.9.2016 KW - Glycan microarray KW - XPS KW - SIMS KW - Fluorescence spectroscopy PY - 2016 AN - OPUS4-37638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lindner, Uwe A1 - Lingott, Jana A1 - Telgmann, L. A1 - Richter, Silke A1 - Jiang, W. A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Speciation of Gd contrast agents using HILIC-ICP-MS N2 - Hydrophilic interaction chromatography (HILIC)coupled with inductively coupled plasma mass spectrometry (ICP-MS) were optimised for the direct determination of gadolinium-based contrast agents in tap water. With the speciation method described, tap water samples from the area of Berlin were analysed and for the first time, three Gd species, Gd-BT-DO3A, Gd-DOTA and Gd-BOPTA, were found in tap water samples at concentrations of about 10–20 ng Gd per litre. These are the same Gd species which have been previously detected predominantly in surface waters of the Berlin area. T2 - Anwendertreffen Plasmaspektrometrie CY - Berlin, Germany DA - 22.02.2016 KW - Gadolinium-based contrast agents KW - Hydrophilic interaction chromatography (HILIC) KW - Speciation KW - Inductively coupled plasmamass spectrometry (ICP-MS) KW - Internal standard KW - Berlin tap water PY - 2016 AN - OPUS4-35875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bolz, Axel A1 - Panne, Ulrich A1 - Rurack, Knut A1 - Buurman, Merwe T1 - Paper-based SERS test strips N2 - For the non-destructive chemical analysis of organic compounds, several different methods such as NMR, UV-vis absorption, IR, Raman, or fluorescence spectroscopy are available. However, all available methods have some restrictions such as the necessity of a large sample amount, interferences in the presence of water, or overlapping signals from the analytes or matrix. Surface enhanced Raman scattering (SERS) allows to observe analytes directly without labelling in low concentrations in aqueous solutions and to identify them by their spectral fingerprint. Therefore, in this work we use SERS as a detection method for different analytes in low concentrations in combination with paper-based test strips as SERS substrates and for sample preparation. We present a spray method for the preparation of SERS test stripes.[1] With this spray method, nanoparticle solution was deposited on cellulose and glass fibre paper as SERS substrate. The prepared paper-based test strips were tested with classical SERS reporter molecules, e.g. rhodamine 6G, 4-aminothiophenol, and adenine. For the quantification of analytes, highly reproducible signal intensities are necessary, which can be realized with the test strips in acceptable quality. Moreover, employing intensity vs concentration calibration for the analytes, data analysis revealed a behaviour that was best described by a Langmuir isotherm, stressing the strong distance dependence of the SERS effect. For an easier identification of analytes in a mixture of compounds, the paper-based test strips were functionalised with hydrophobic barriers by wax printing. With these microfluidic paper-based analytical devices (µPAD) the sample mixture can be separated by the chromatographic effects of the paper and the different analytes can be separately detected and identified by SERS. [1] A. Bolz, U. Panne, K. Rurack, M. Buurman, Glass fibre paper-based test strips for sensitive SERS sensing, Anal. Methods, 2016, 8, 1313-1318. T2 - International RamanFest 2016 CY - Berlin, Germany DA - 19.05.2016 KW - SERS KW - Raman KW - Paper PY - 2016 AN - OPUS4-36726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao A1 - Weidner, Steffen A1 - Jakubowski, Norbert A1 - Meier, F. A1 - Panne, Ulrich T1 - Comparison of the separation performance of a conventional and a miniaturized AF4 channel N2 - A miniaturized AF4 channel was introduced for the rapid analysis of different nanoparticle samples. UV-Vis-MALS provides the possibility to measure the particle size and molar mass and offers a powerful tool for the investigation of separation performances of different AF4 channels. T2 - BfR Retreat 2016 CY - Berlin, Germany DA - 23.09.2016 KW - Field-flow fractionation KW - Miniaturized AF4 channel PY - 2016 AN - OPUS4-38255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. A1 - Shabanov, Sergej V. A1 - Demidov, Alexander A1 - Glaus, Reto A1 - Panne, Ulrich T1 - Diagnostics and modeling of laser induced plasma in relation to current needs of spectrochemical analysis N2 - The short report on computer modeling and diagnostics of laser induced plasmas T2 - Winter Plasma Conference CY - Tucson, USA DA - 08.01.2016 KW - Plasma diagnostics KW - Laser induced plasma KW - LIBS KW - Plasma modeling PY - 2016 AN - OPUS4-38773 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abdelshafi, Nahla A. A1 - Panne, Ulrich A1 - Schneider, Rudolf T1 - Microfluidic electrochemical immunosensor for cocaine monitoring N2 - Immunoassays based on the detection of the antibody-antigen interaction belong to the most important analytical techniques. Electrochemical methods in immunoassays are increasingly used as they offer some Advantages as being fast, simple, portable and cheap detection methods. Cocaine is a highly addictive stimulant that occurs naturally as an Alkaloid of the Coca plants. It is frequently detected on bank notes and in wastewater. T2 - Biosensors 2016 CY - Gothenburg, Sweden DA - 25.05.2016 KW - Cocain PY - 2016 AN - OPUS4-38552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Phukphatthanachai, Pranee A1 - Vogl, Jochen A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Determination of total sulfur in a metal matrix by ICP-IDMS: Example Cu matrix N2 - Previously on sulfur determination in metal revealed a lack of traceability and inconsistent results. Solving the problems a reference procedure for sulfur measurement in metal are required to build up a reliable reference value. In this study a procedure was developed for quantification of total sulfur at low concentration (in sub ppm level) in metal using inductively coupled plasma-isotope dilution mass spectrometry (ICP-IDMS). The ion exchange method and complexing agent were applied in this procedure to avoid loading large amount of metal into the instrument. Adding ammonia as a complexing agent into sample solution to reduce sulfur-metal co-elute. The procedure shows high performance and it is expressed in % recovery of sulfur (> 90%) and % metal elimination (>99 %). Additionally, relative measurement uncertainties were calculated less than 1.5 % and the results are traceable directly to SI units. This study would establish as reference procedure for sulfur measurement in metal sample which fit for these purpose as follows; for certified reference material and assigned value for inter-laboratory comparison. T2 - Anwendertreffen Plasmaspektrometrie 2016 CY - Berlin, Germany DA - 22.02.2016 KW - IDMS KW - Sulfur-matrix separatio KW - Purity assessment PY - 2016 AN - OPUS4-40027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sturm, Heinz T1 - Friction-induced explosive reactions N2 - The motivation to examine the influence of friction on surfaces of energetic materials (EM) has diverse backgrounds. On the one hand the very old hot spot theory predicts, that the size of such hot spot could be in the range of a molecule. The initiation of an EM could start by mechanical excitation, i.e. friction, and continues driven by an exothermal chemical reaction. Following such phenomena on the molecular scale with an imaging method such as AFM should enable us to separate several steps of ignition, if there are any. The experiments showed that HMX mainly undergoes a plastic deformation without further consequences. TNP however showed self healing in the wear track after scratching and simultaneously the destruction of a crystal edge outside the wear track. Additionally nanoparticles appear, tribologists call this "third body formation", which are proven to have a different chemical composition as the original TNP. The self healing effect on the surface is verified with experiments on self diffusion of TNP molecules to and fro the free edges of the crystal. The conclusion is that the formation of a hot spot can be shown to consist of several subsequent steps, separated temporally and locally. The goal to excite the thermal decomposition of a whole TNP crystal (nanoexplosion) was yet not reached due to unfavourable conditions related to thermal conductivity and build-up of pressure. T2 - Role of Third Bodies in Tribology, Colloquium of 5.1 CY - BAM, Berlin, Germany DA - 09.06.2016 KW - AFM KW - Energetic material KW - Hot spot KW - Friction PY - 2016 AN - OPUS4-36433 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 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 - CONF A1 - Wunderle, B. A1 - Onken, T. A1 - Heilmann, J. A1 - Silbernagl, Dorothee A1 - Arnold, J. A1 - Bieniek, T. A1 - Pufall, R. T1 - Reliability of sputtered thin aluminium films under accelerated stress testing by vibration loading and modeling N2 - Aluminium is still one of the most important contact metallisations for power electronic chips like MOSFETs or IGBTs. With a large difference in thermal expansion coefficients (CTEs) between aluminium and silicon and the temperatures generated in hot-spots during high power transients, these layers are prone to failure due to thermo-mechanical fatigue. Usually lifetime assessment is done by subjecting dedicated test specimens to standardised stress tests as e.g. active or passive thermal cycling. This paper proposes a novel method for accelerated stress testing and lifetime modelling of thin aluminium films in the high-cycle fatigue regime by isothermal mechanical loading. The proposed novel test method is suggested to complement or replace resource-demanding thermal cycling tests and allow simple in-situ monitoring of failure. T2 - 6th Electronic System-Integration Technology Conference (ESTC) CY - Grenoble, France DA - 13.09.2016 KW - Semiconductor device reliability KW - Thermal expansion KW - AFM KW - Vibrations KW - Nanoroughness KW - Accelerated stress testing KW - Active thermal cycling KW - Power electronic chips KW - Sputtered thin aluminium film KW - Thermomechanical fatigue PY - 2016 DO - https://doi.org/10.1109/ESTC.2016.7764458 SP - 1 EP - 14 PB - IEEE AN - OPUS4-43595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hartmann, S A1 - Sturm, Heinz A1 - Blaudeck, T A1 - Hoelck, O A1 - Hermann, S A1 - Schulz, SE A1 - Wunderle, B. T1 - Experimental and computational studies on the role of surface functional groups in the mechanical behavior of interfaces between single-walled carbon nanotubes and metals N2 - To study the mechanical interface behavior of single-walled carbon nanotubes (CNTs) embedded in a noble metal, we performed CNT-metal pull-out tests with in situ scanning electron microscope experiments. Molecular dynamics (MD) simulations were conducted to predict force-displacement data during pull-out, providing critical forces for failure of the system. In MD simulations, we focused on the influence of carboxylic surface functional groups (SFGs) covalently linked to the CNT. Experimentally obtained maximum forces between 10 and 102 nN in palladium and gold matrices and simulated achievable pulling forces agree very well. The dominant failure mode in the experiment is CNT rupture, although several pull-out failures were also observed. We explain the huge scatter of experimental values with varying embedding length and SFG surface density. From simulation, we found that SFGs act as small anchors in the metal matrix and significantly enhance the maximum forces. This interface reinforcement can lead to tensile stresses sufficiently high to initiate CNT rupture. To qualify the existence of carboxylic SFGs on our CNT material, we performed analytical investigation by means of fluorescence labeling of surface species and discuss the results. With this contribution, we focus on a synergy between computational and experimental approaches involving MD simulations, nano scale testing, and analytics (1) to predict to a good degree of accuracy maximum pull-out forces of single-walled CNTs embedded in a noble metal matrix and (2) to provide valuable input to understand the underlying mechanisms of failure with focus on SFGs. This is of fundamental interest for the design of future mechanical sensors incorporating piezoresistive single-walled CNTs as the sensing element. KW - Oxygen-containing functionalities KW - Molecular-dynamics KW - Structural characterization KW - Reinforced composites KW - Raman spectroscopy KW - Shear strength KW - Polymer matrix KW - Pull-out KW - Simulation KW - Purification PY - 2016 DO - https://doi.org/10.1007/s10853-015-9142-6 SN - 0022-2461 SN - 1573-4803 VL - 51 IS - 3 SP - 1217 EP - 1233 AN - OPUS4-35795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lisec, Jan T1 - InterpretMSSpectrum (R package to annotate mass spectra) N2 - Gas chromatography using atmospheric pressure chemical ionization coupled to mass spectrometry (GC/APCI-MS) is an emerging metabolomics platform, providing much-enhanced capabilities for structural mass spectrometry as compared to traditional electron ionization (EI)-based techniques. To exploit the potential of GC/APCI-MS for more comprehensive metabolite annotation, a major bottleneck in metabolomics, we here present the novel R-based tool InterpretMSSpectrum assisting in the common task of annotating and evaluating in-source mass spectra as obtained from typical full-scan experiments. After passing a list of mass-intensity pairs, InterpretMSSpectrum locates the molecular ion (M0), fragment, and adduct peaks, calculates their most likely sum formula combination, and graphically summarizes results as an annotated mass spectrum. Using (modifiable) filter rules for the commonly used methoximated-trimethylsilylated (MeOx-TMS) derivatives, covering elemental composition, typical substructures, neutral losses, and adducts, InterpretMSSpectrum significantly reduces the number of sum formula candidates, minimizing manual effort for postprocessing candidate lists. We demonstrate the utility of InterpretMSSpectrum for 86 in-source spectra of derivatized standard compounds, in which rank-1 sum formula assignments were achieved in 84% of the cases, compared to only 63% when using mass and isotope information on the M0 alone. We further use, for the first time, automated annotation to evaluate the purity of pseudospectra generated by different metabolomics preprocessing tools, showing that automated annotation can serve as an integrative quality measure for peak picking/deconvolution methods. As an R package, InterpretMSSpectrum integrates flexibly into existing metabolomics pipelines and is freely available from CRAN (https://cran.r-project.org/). KW - Mass Spectrometry KW - Spectra annotation KW - Software KW - R package PY - 2016 UR - https://github.com/cran/InterpretMSSpectrum/ PB - GitHub CY - San Francisco, CA, USA AN - OPUS4-57856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer-Plath, Asmus A1 - Beckert, F A1 - Tölle, FJ A1 - Sturm, Heinz A1 - Mülhaupt, R T1 - Stable aqueous dispersions of functionalized multi-layer graphene by pulsed underwater plasma exfoliation of graphite N2 - A process was developed for graphite particle exfoliation in water to stably dispersed multi-layer graphene. It uses electrohydraulic shockwaves and the functionalizing effect of solution plasma discharges in water. The discharges were excited by 100 ns high voltage pulsing of graphite particle chains that bridge an electrode gap. The underwater discharges allow simultaneous exfoliation and chemical functionalization of graphite particles to partially oxidized multi-layer graphene. Exfoliation is caused by shockwaves that result from rapid evaporation of carbon and water to plasma-excited gas species. Depending on discharge energy and locus of ignition, the shockwaves cause stirring, erosion, exfoliation and/or expansion of graphite flakes. The process was optimized to produce long-term stable aqueous dispersions of multi-layer graphene from graphite in a single process step without requiring addition of intercalants, surfactants, binders or special solvents. A setup was developed that allows continuous production of aqueous dispersions of flake size-selected multi-layer graphenes. Due to the well-preserved sp(2)-carbon structure, thin films made from the dispersed graphene exhibited high electrical conductivity. Underwater plasma discharge processing exhibits high innovation potential for morphological and chemical modifications of carbonaceous materials and surfaces, especially for the generation of stable dispersions of two-dimensional, layered materials. KW - Exfoliation KW - Graphene KW - Aqueous dispersion KW - Solution plasma KW - Functionalization KW - Electrohydraulic effect KW - Shear exfoliation KW - Oxide-films KW - Water PY - 2016 DO - https://doi.org/10.1088/0022-3727/49/4/045301 SN - 0022-3727 VL - 49 IS - 4 SP - 045301-1 EP - 045301-11 AN - OPUS4-35796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao A1 - Weidner, Steffen T1 - Determination of chromatographic parameters of a miniaturized AF4 channel and its comparison with a conventioanl AF4 channel N2 - The performance of a miniaturized channel for the separation of polymer and metal nanoparticles (NP) using Asymmetrical Flow Field-Flow Fractionation (AF4) was investigated and compared with a conventional AF4 system. To develop standard separation methods, experimental parameters like cross flow, gradient profile and injection time were varied and optimized. Corresponding chromatographic parameters were calculated and compared. Our results indicate that the chromatographic resolution in the miniaturized channel is lower, whereas significantly shorter analyses time and less solvent consumption were obtained. Moreover, the limit of detection (LOD) and limit of quantification (LOQ) obtained from hyphenation with a UV-detector are obviously lower than in a conventional channel, which makes the miniaturized channel interesting for trace analysis. T2 - BAM Seminar CY - Berlin, Germany DA - 31.08.2016 KW - Nanoparticles separation asymetrical flow field flow fractionation PY - 2016 AN - OPUS4-47190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao A1 - Weidner, Steffen A1 - Meier, Florian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Comparison of the separation performance of a conventional and a miniaturized AF4 channels N2 - Currently available separation channels for asymmetric flow field-flow fractionation (AF4), which results in long analysis time and solvent consumption, limits the application of AF4 in [1} the field of nanoparticle analysis . A miniaturized AF4 channel was introduced for the rapid analysis of different nanoparticle samples. UV-Vis-MALS provides the possibility to measure the particle size and molar mass and offers a powerful tool for the investigation of [2] separation performances of different AF4 channels . Our objective was to develop fast and reliable separation methods for both channels and enable a direct comparison by the corresponding chromatographic parameters. T2 - 2016 BfR PhD Retreat DA - 31.08.2016 KW - Nanoparticles separation asymetrical flow field flow fractionation PY - 2016 AN - OPUS4-47192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Chemical and electrochemical interaction mechanisms of metal-reducing bacteria with gold surfaces N2 - Bacterial biofilms are considered one of the salient contributing factors to the deterioration of metals and their alloys, occurring in virtually all environments and across various industrial systems. Considering the sheer magnitude of detrimental effects, it is of pertinent interest to elucidate the interaction mechanisms of sessile bacteria with metal and metal oxide surfaces to facilitate the development of efficient antifouling strategies. A common constituent of microbial communities within aquatic and sedimentary settings, the Shewanella genus consists of facultatively aerobic, Gram-negative bacterium which exhibit exceptional plasticity in respiratory capacities. During aerobic conditions, Shewanella utilizes oxygen as a terminal electron acceptor; conversely, under anaerobic conditions, it is able to undertake respiration by reducing alternative terminal electron acceptors such as oxidized metals via extracellular electron transfer mechanisms not yet thoroughly discerned. The aim of this work is to explicate the mechanisms governing the initial bacterial adhesion and subsequent biofilm formation on metallic surfaces. To investigate this dynamic interplay, a combined approach has been followed which couples surface enhanced Raman spectroscopy (SERS) with electrochemical techniques using Shewanella sp. model biofilms. Gold nano-islands deposited on thin glass slides have been chosen as inert model substrates with good uniformity and high surface enhancement factor. Furthermore, the utilization of gold as substrate material not only allowed the differentiation of the sole effect of substrate polarization on bacterial attachment but also enabled a precise adjustment of the surface chemistry and surface energy by means of surface functionalization with organothiol self-assembled monolayers. The results present the correlation of the primary settlement rate of bacteria on metallic substrates with the environmental parameters such as electrolyte composition and pH as well as surface-related properties like hydrophobicity/hydrophilicity and polarization. With the overall strategic goal of transferring this methodology to technical systems the results provide the fundamental basis for the bottom-up design of anti-fouling surfaces. T2 - Electrochemistry 2016 CY - Göslar, Germany DA - 26.09.2016 KW - Bacterial biofilms KW - Electrochemistry KW - Microbiology KW - Surface enhanced Raman spectroscopy KW - Raman spectroscopy KW - Microbiologically induced corrosion KW - Anti-fouling KW - Shewanella KW - Biocorrosion PY - 2016 AN - OPUS4-47243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Özcan Sandikcioglu, Özlem T1 - Chemical and electrochemical interaction mechanisms of metal-reducing bacteria with gold surfaces N2 - Bacterial biofilms are considered one of the salient contributing factors to the deterioration of metals and their alloys, occurring in virtually all environments and across various industrial systems. Considering the sheer magnitude of detrimental effects, it is of pertinent interest to elucidate the interaction mechanisms of sessile bacteria with metal and metal oxide surfaces to facilitate the development of efficient antifouling strategies. A common constituent of microbial communities within aquatic and sedimentary settings, the Shewanella genus consists of facultatively aerobic, Gram-negative bacterium which exhibit exceptional plasticity in respiratory capacities. During aerobic conditions, Shewanella utilizes oxygen as a terminal electron acceptor; conversely, under anaerobic conditions, it is able to undertake respiration by reducing alternative terminal electron acceptors such as oxidized metals via extracellular electron transfer mechanisms not yet thoroughly discerned. The aim of this work is to explicate the mechanisms governing the initial bacterial adhesion and subsequent biofilm formation on metallic surfaces. To investigate this dynamic interplay, a combined approach has been followed which couples surface enhanced Raman spectroscopy (SERS) with electrochemical techniques using Shewanella sp. model biofilms. Gold nano-islands deposited on thin glass slides have been chosen as inert model substrates with good uniformity and high surface enhancement factor. Furthermore, the utilization of gold as substrate material not only allowed the differentiation of the sole effect of substrate polarization on bacterial attachment but also enabled a precise adjustment of the surface chemistry and surface energy by means of surface functionalization with organothiol self-assembled monolayers. The results present the correlation of the primary settlement rate of bacteria on metallic substrates with the environmental parameters such as electrolyte composition and pH as well as surface-related properties like hydrophobicity/hydrophilicity and polarization. With the overall strategic goal of transferring this methodology to technical systems the results provide the fundamental basis for the bottom-up design of anti-fouling surfaces. T2 - Electrochemistry 2016 CY - Göslar, Germany DA - 26.09.2016 KW - Biofilms KW - Electrochemistry KW - Biocorrosion KW - Surface enhanced Raman Spectroscopy KW - Bacteria KW - Microbiological induced corrosion KW - Microbiology PY - 2016 AN - OPUS4-47246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kastanias, Elaine A1 - Özcan Sandikcioglu, Özlem T1 - Chemical and electrochemical interaction mechanisms of metal-reducing bacteria with gold surfaces N2 - Bacterial biofilms are considered one of the salient contributing factors to the deterioration of metals and their alloys, occurring in virtually all environments and across various industrial systems. Considering the sheer magnitude of detrimental effects, it is of pertinent interest to elucidate the interaction mechanisms of sessile bacteria with metal and metal oxide surfaces to facilitate the development of efficient antifouling strategies. A common constituent of microbial communities within aquatic and sedimentary settings, the Shewanella genus consists of facultatively aerobic, Gram-negative bacterium which exhibit exceptional plasticity in respiratory capacities. During aerobic conditions, Shewanella utilizes oxygen as a terminal electron acceptor; conversely, under anaerobic conditions, it is able to undertake respiration by reducing alternative terminal electron acceptors such as oxidized metals via extracellular electron transfer mechanisms not yet thoroughly discerned. The aim of this work is to explicate the mechanisms governing the initial bacterial adhesion and subsequent biofilm formation on metallic surfaces. To investigate this dynamic interplay, a combined approach has been followed which couples surface enhanced Raman spectroscopy (SERS) with electrochemical techniques using Shewanella sp. model biofilms. Gold nano-islands deposited on thin glass slides have been chosen as inert model substrates with good uniformity and high surface enhancement factor. Furthermore, the utilization of gold as substrate material not only allowed the differentiation of the sole effect of substrate polarization on bacterial attachment but also enabled a precise adjustment of the surface chemistry and surface energy by means of surface functionalization with organothiol self-assembled monolayers. The results present the correlation of the primary settlement rate of bacteria on metallic substrates with the environmental parameters such as electrolyte composition and pH as well as surface-related properties like hydrophobicity/hydrophilicity and polarization. With the overall strategic goal of transferring this methodology to technical systems the results provide the fundamental basis for the bottom-up design of anti-fouling surfaces. T2 - Electrochemistry 2016 CY - Goslar, Germany DA - 26.09.2016 KW - Biofilms KW - Electrochemistry KW - Microbiology KW - Bacterial Extracellular Electron Transfer Mechanisms KW - Surface Enhanced Raman Spectroscopy KW - Spectroelectrochemical Techniques KW - Biocorrosion PY - 2016 AN - OPUS4-47249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -