TY - JOUR A1 - Emmerling, Franziska A1 - Martins, Ines T1 - Carbamazepine Dihydroxybenzoic Acid Cocrystals: Exploring Packing Interactions and Reaction Kinetics N2 - Herein, we present the mechanochemical formation of three new cocrystals containing the active pharmaceutical ingredient carbamazepine and dihydroxybenzoic acids as coformers (CBZ:2,4-DHBA 1:1, CBZ:2,5-DHBA 1:1, and CBZ:2,6-DHBA 1:1). Rietveld methods were used for three different purposes: (i) refining all structures solved using powder X-ray diffraction, (ii) performing a quantitative phase analysis of the diffraction data collected from ex situ mechanochemical reactions at different milling times, and (iii) determining the cocrystallization kinetic profiles. The rate of cocrystallization was found to be higher for the formation of CBZ:2,4-DHBA and CBZ:2,6-DHBA, reaching an equilibrium after 600 s of milling. In the case of CBZ:2,5-DHBA a short induction period of 20 s was detected prior to the start of the reaction and an equilibrium was reached after 1200 s. An empirical trend between the rate of cocrystallization and the structural complexity of the cocrystal product was found. The slowest cocrystallization rate observed for CBZ:2,5-DHBA corresponds to the crystal structure deviating substantially from the hydrogen-bonding motif found in the reactants. KW - Mechanochemistry KW - In situ real-time monitoring KW - Kinetics PY - 2021 DO - https://doi.org/10.1021/acs.cgd.1c00902 VL - 21 IS - 12 SP - 6961 EP - 6970 PB - ACS Publications AN - OPUS4-54407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lakshmipathi, M. A1 - Tothadi, S. A1 - Emmerling, Franziska A1 - Bhattacharya, Biswajit A1 - Ghosh, S. T1 - Different mechanical responses of dimorphic forms of Anthracene Schiffbase crystal N2 - We obtained concomitant dimorphic forms of Anthracene Schiffbase (N-(anthracen-9-yl methylene)-2,5- dichloroaniline) from hexane solvent. Two polymorphs can be differentiated by their morphology and mechanical properties. One form is long acicular type and elastically bendable while another form is block shaped and brittle in nature. Mechanical property is attributed to underlying crystal packing. Hirsh- feld analysis and energy framework calculations were done to corroborate structure-property correlation of two forms. KW - Elasticity KW - Mechanical properties KW - Anthracene schiff base KW - Dimorphs PY - 2021 DO - https://doi.org/10.1016/j.molstruc.2021.132182 VL - 1252 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-54356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Casali, C. A1 - Feiler, Torvid A1 - Heilmann, Maria A1 - Braga, D. A1 - Emmerling, Franziska A1 - Grepioni, F. T1 - Too much water? Not enough? In situ monitoring of the mechanochemical reaction of copper salts with dicyandiamide N2 - n situ monitoring of mechanochemical reactions between dicyandiamide (DCD) and CuX2 salts (X = Cl−, NO3−), for the preparation of compounds of agrochemical interest, showed the appearance of a number of phases. It is demonstrated that milling conditions, such as the amount of water added in wet grinding and/or the milling frequency, may affect the course of the mechanochemical reactions, and drive the reaction towards the formation of different products. It has been possible to discover by in situ monitored experiments two novel crystalline forms, namely the neutral complexes [Cu(DCD)2(OH2)2(NO3)2] (2) and [Cu(DCD)2(OH2)Cl2]·H2O (4), in addition to the previously known molecular salt [Cu(DCD)2(OH2)2][NO3]2·2H2O (1, DIVWAG) and neutral complex [Cu(DCD)2(OH2)Cl2] (3, AQCYCU), for which no synthesis conditions were available. Compounds 2 and 4 were fully characterized via a combination of solid-state techniques, including X-ray diffraction, Raman spectroscopy and TGA. KW - Mechanochemistry KW - In situ PY - 2022 DO - https://doi.org/10.1039/d1ce01670a VL - 24 IS - 6 SP - 1292 EP - 1298 PB - RSC AN - OPUS4-54344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Plastik in Böden: Mikroplastik-Ergebnisse N2 - In diesem Vortrag geht um die Vorstellung der Ergebnisse des UBA Projektes Plastik in Böden. Es werden Mikroplastik-Gehalte in verschiedenen Böden präsentiert. T2 - Fachgespräch "Plastik in Böden" CY - Online meeting DA - 28.03.2022 KW - Mikroplastik KW - Mikroplastik Böden KW - Mikroplastik-Analytik PY - 2022 AN - OPUS4-54648 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisentraut, Paul T1 - Qualitätssicherung bei der Analyse von Mikroplastik per TED GC/MS N2 - Die Thermo Extraktion Desorption Gas Chromatograpie Massen Spektrometrie (TED-GC/MS) ist ein schnelles thermoanalytisches Verfahren zur Bestimmung von Gehalten an Mikroplastik (MP). Die Kombination aus teils schwerflüchtigen Analyten und Kältebrücken führt zu Memory-Effekten, denen u.a. durch häufige Blindwertmessungen begegnet werden muss. Reduzierte Probedurchsätze sind die Folge. Um Messergebnisse abzusichern und den Gerätestatus bei gleichzeitig hoher Messleistung überwachen zu können, wurde die sequentielle Standardmethode überarbeitet. T2 - Tagung der Wasserchemischen Gesellschaft 2022 CY - Online meeting DA - 23.05.2022 KW - Mikroplastik KW - Thermoanalytik KW - TED-GC/MS KW - Qualitätssicherung PY - 2022 AN - OPUS4-55087 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Mikroplastik heute: Was haben wir in den letzten Jahren erreicht? N2 - In diesem Vortrag geht es um eine Übersicht über die Thematik der Mikroplastik, Was ist Mikroplastik, wie entsteht es und wo kommt es her. Es wird beschrieben wie eine repräsentative Probenahme erfolgen kann und wie welche Herausforderungen bei der Probenvorbereitung existieren. Die Detektion wird ausführlich beschrieben, sowohl mit Partikelanzahl als auch Masse. Im weiteren werden erste Referenzmaterialien und ihre Anwendung in internationalen Ringversuchen beschrieben. Der zweite Teil zeigt die Normungsaktivitäten im Bereich der Mikroplastik. T2 - Mitgliederversammlung der GdCh Lackchemie CY - Online Meeting DA - 20.09.2024 KW - Mikroplastik KW - TED-GC/MS KW - Polymer 3R KW - Reference material KW - ILC on detection methods PY - 2024 AN - OPUS4-61087 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Moeez, A. A1 - Hörmann, Anja A1 - Breßler, Ingo T1 - Example configurations and test cases for the Python HDF5Translator framework. N2 - This is a set of use examples for the HDF5Translator framework. This framework lets you translate measurement files into a different (e.g. NeXus-compatible) structure, with some optional checks and conversions on the way. For an in-depth look at what it does, there is a blog post here. The use examples provided herein are each accompanied by the measurement data necessary to test and replicate the conversion. The README.md files in each example show the steps necessary to do the conversion for each. We encourage those who have used or adapted one or more of these exampes to create their own conversion, to get in touch with us so we may add your example to the set. KW - Measurement data conversion KW - Data conversion KW - HDF5 KW - NeXus KW - NXsas KW - Framework KW - Python PY - 2024 DO - https://doi.org/10.5281/zenodo.10925971 PB - Zenodo CY - Geneva AN - OPUS4-59796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob T1 - The SPONGE N2 - This software tool is intended to calculate X-ray scattering patterns from 3D objects described by an STL file. The fundamentals and use example(s) are shown. T2 - Better with Scattering workshop 2020 CY - BAM, Berlin, Germany DA - 16.03.2020 KW - Small angle scattering KW - Software KW - Simulation PY - 2020 AN - OPUS4-51020 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Glimpses of the Future : Advancing X-ray Scattering in an Automated Materials Research Laboratory N2 - In our (dramatically understaffed) X-ray scattering laboratory, developing a systematic, holistic methodology1 let us provide scattering and diffraction information for more than 2100 samples for 200+ projects led by 120+ collaborators. Combined with automated data correction pipelines, and our analysis and simulation software, this led to more than 40 papers2 in the last 5 years with just over 2 full-time staff members. This year, our new, modular synthesis platform has made more than 1000 additional samples for us to analyse and catalogue. By virtue of the automation, the synthesis of these samples is automatically documented in excruciating detail, preparing them for upload and exploitation in large-scale materials databases. Having developed these proof-of-concepts, we find that materials research itself is changed dramatically by automating dull tasks in a laboratory. This talk is intended to spark ideas and invite collaborations by providing an overview of: 1) the current improvements in our wide-range X-ray scattering laboratory methodology, 2) Introduce some of our open-source analysis and simulation software, touching on scattering, diffraction and PDF, and 3) introducing our open, modular robotic platform for systematic sample preparation. Finally, the remaining bottlenecks and points of attention across all three are highlighted. T2 - Swiss Society for Crystallography (SSCr) annual meeting CY - Zurich, Switzerland DA - 08.09.2023 KW - Lab automation KW - Fourier transforms KW - X-ray scattering KW - Robotic synthesis KW - Data stewardship KW - Holistic experimental procedures KW - MOUSE KW - Metal-organic frameworks KW - High-throughput measurements PY - 2023 AN - OPUS4-58237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cakir, Cafer Tufan A1 - Piotrowiak, T. A1 - Reinholz, Uwe A1 - Ludwig, A. A1 - Emmerling, Franziska A1 - Streli, C. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin T1 - Exploring the Depths of Corrosion: A Novel GE-XANES Technique for Investigating Compositionally Complex Alloys N2 - In this study, we propose the use of nondestructive, depth-resolved, element-specific characterization using grazing exit X-ray absorption near-edge structure spectroscopy (GE-XANES) to investigate the corrosion process in compositionally complex alloys (CCAs). By combining grazing exit X-ray fluorescence spectroscopy (GE-XRF) geometry and a pnCCD detector, we provide a scanning-free, nondestructive, depth-resolved analysis in a sub-micrometer depth range, which is especially relevant for layered materials, such as corroded CCAs. Our setup allows for spatial and energy-resolved measurements and directly extracts the desired fluorescence line, free from scattering events and other overlapping lines. We demonstrate the potential of our approach on a compositionally complex CrCoNi alloy and a layered reference sample with known composition and specific layer thickness. Our findings indicate that this new GE-XANES approach has exciting opportunities for studying surface catalysis and corrosion processes in real-world materials. KW - Degradation mechanisms KW - Grazin exit XANES KW - Depth resolved XANES KW - Compositional complex alloys KW - Corrosion PY - 2023 DO - https://doi.org/10.1021/acs.analchem.3c00404 VL - 95 SP - 4810 EP - 4818 PB - ACS Publications AN - OPUS4-57823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Holger A1 - Baldofski, Stefanie A1 - Hoffmann, Kristin A1 - Flemig, Sabine A1 - Silva, C. P. A1 - Esteves, V. I. A1 - Emmerling, Franziska A1 - Panne, Ulrich A1 - Schneider, Rudolf T1 - Structural considerations on the selectivity of an immunoassay for sulfamethoxazole N2 - Sulfamethoxazol (SMX),a sulfonamide, is a widely used bacteriostatic antibiotic and therefore a promising marker for the entry of anthropogenic Pollution in the environment. SMX is frequently found in wastewater and surface water. This study presents the production of high affinity and selective polyclonal antibodies for SMX and the development and Evaluation of a direct competitive enzyme-linked immunosorbent assay(ELISA)for the quantification of SMX in environmental watersamples. The crystal structures of the cross-reacting compounds sulfamethizole, N4-acetyl-SMX andsuccinimidyl-SMX were determined by x-ray diffraction aiming to explain their high cross-reactivity. These crystal structures are described for the first time. The quantification range of the ELISA is 0.82–63 µg/L. To verify our results, the SMX concentration in 20 environmental samples,including wastewater and surfacewater,was determined by ELISA and tandem mass spectrometry(MS/MS).A good Agreement of the measured SMX concentrations was found with average recoveries of 97–113%for the results of ELISA compared to LC-MS/MS. KW - X-Ray diffraction KW - Sulfamethoxazole KW - ELISA KW - LC-MS/MS PY - 2016 DO - https://doi.org/10.1016/j.talanta.2016.05.049 SN - 0039-9140 SN - 1873-3573 IS - 158 SP - 198 EP - 207 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-36676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Surov, Artem O. A1 - Vasilev, Nikita A. A1 - Churakov, Andrei V. A1 - Stroh, Julia A1 - Emmerling, Franziska A1 - Perlovich, German L. T1 - Solid Forms of Ciprofloxacin Salicylate: Polymorphism, Formation Pathways, and Thermodynamic Stability N2 - The crystallization of ciprofloxacin - an antibacterial fluoroquinolone compound - with salicylic acid resulted in the isolation of five distinct solid forms of the drug, namely, an anhydrous salt, two polymorphic forms of the salt monohydrate, methanol and acetonitrile solvates, and the salt-cocrystal hydrate. The salicylate salts were investigated by different analytical techniques ranging from powder and single crystal X-ray diffractometry, differential scanning calorimetry, thermogravimetric analysis, variable temperature powder X-ray diffraction, dynamic vapor sorption analysis, dissolution, and solubility investigations. Real-time in situ Raman spectroscopy was used to investigate the mechanochemical formation pathways of the different solid polymorphs of ciprofloxacin salicylate. The mechanism of the phase transformation between the crystalline forms was evaluated under mechanochemical conditions. It was found that the formation pathway and kinetics of the grinding process depend on the form of the starting material and reaction conditions. The analysis of the solid-state thermal evolution of the hydrated salts revealed the two-step mechanism of dehydration process, which proceeds through a formation of the distinct intermediate crystalline products. KW - Cocrystal KW - Polymorphism KW - Ciprofloxacin KW - XRD KW - DSC PY - 2019 DO - https://doi.org/10.1021/acs.cgd.9b00185 SN - 1528-7483 VL - 19 IS - 5 SP - 2979 EP - 2990 PB - American Chemical Society AN - OPUS4-47903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heilmann, Maria A1 - Simões, R. G. A1 - Bernardes, C. E. S. A1 - Ramisch, Yen A1 - Bienert, Ralf A1 - Röllig, Matthias A1 - Emmerling, Franziska A1 - Minas da Piedade, M. E. T1 - Real-Time In situ XRD Study of Simvastatin Crystallization in Levitated Droplets N2 - Simvastatin (SV) is an important active pharmaceutical ingredient (API) for treatment of hyperlipidemias, which is known to exist in different crystalline and amorphous phases. It is, therefore, an interesting model to investigate how the outcome of evaporative crystallization in the contactless environment of an acoustically levitated droplet may be influenced by key experimental conditions, such as temperature, solvent properties (e.g., polarity and hygroscopicity), and dynamics of the evaporation process. Here, we describe a real-time and in situ study of simvastatin evaporative crystallization from droplets of three solvents that differ in volatility, polarity, and protic character (acetone, ethanol, and ethyl acetate). The droplet monitorization relied on synchrotron X-ray diffraction (XRD), Raman spectroscopy, imaging, and thermographic analysis. A pronounced solvent-dependent behavior was observed. In ethanol, a simvastatin amorphous gel-like material was produced, which showed no tendency for crystallization over time; in ethyl acetate, a glassy material was formed, which crystallized on storage over a two-week period to yield simvastatin form I; and in acetone, form I crystallized upon solvent evaporation without any evident presence of a stable amorphous intermediate. The XRD and Raman results further suggested that the persistent amorphous phase obtained from ethanol and the amorphous precrystallization intermediate formed in ethyl acetate were similar. Thermographic analysis indicated that the evaporation process was accompanied by a considerable temperature decrease of the droplet surface, whose magnitude and rate correlated with the solvent volatility (acetone > ethyl acetate > ethanol). The combined thermographic and XRD results also suggested that, as the cooling effect increased, so did the amount of residual water (most likely captured from the atmosphere) remaining in the droplet after the organic solvent was lost. Finally, the interpretation of the water fingerprint in the XRD time profiles was aided by molecular dynamics simulations, which also provided insights into the possible role of H2O as an antisolvent that facilitates simvastatin crystallization. KW - Simvastatin KW - In-situ KW - API KW - Crystallization PY - 2021 DO - https://doi.org/10.1021/acs.cgd.1c00509 SN - 1528-7483 VL - 21 IS - 8 SP - 4665 EP - 4673 PB - ACS Publications AN - OPUS4-53663 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical processes N2 - Overview of the present BAM activities in the field of in situ analytics of mechanochemical processes. Recent results for the synthesis of metal organic frameworks and cocrystals are presented. T2 - HZB Seminar CY - Online meeting DA - 21.01.2022 KW - Mechanochemistry KW - In situ real-time monitoring PY - 2022 AN - OPUS4-54296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In-situ investigations of mechanochemical reactions N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic[1], metal-organic[2], and inorganic[3] compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms remain often unclear. In the last years, have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy.[4] Here, we present an in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time.[5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - ACS Conference Boston CY - Boston, USA DA - 19.08.2018 KW - Mechanochemistry KW - In situ KW - Kinetic PY - 2018 AN - OPUS4-46989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Emmerling, Franziska T1 - Experimantal raw data sets associated with certified reference material BAM-P116 (titanium dioxide) for comparison of nitrogen and argon sorption, available in the universal adsorption information format (AIF) N2 - These data sets serve as models for calculating the specific surface area (BET method) using gas sorption in accordance with ISO 9277. The present measurements were carried out with nitrogen at 77 Kelvin and argon at 87 Kelvin. It is recommended to use the following requirements for the molecular cross-sectional area: Nitrogen: 0.1620 nm² Argon: 0.1420 nm² Titanium dioxides certified with nitrogen sorption and additionally measured with argon for research purposes were used as sample material. The resulting data sets are intended to serve as comparative data for own measurements and show the differences in sorption behaviour and evaluations between nitrogen and argon. These data are stored in the universal AIF format (adsorption information file), which allows flexible use of the data. KW - Physisorption KW - Surface area KW - AIF KW - Argon KW - Nitrogen PY - 2023 DO - https://doi.org/10.5281/zenodo.10199628 PB - Zenodo CY - Geneva AN - OPUS4-59102 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bauer, J. A1 - Miclea, P.-T. A1 - Braun, U. A1 - Altmann, Korinna A1 - Turek, M. A1 - Hagendorf, C. T1 - Microplastic detection and analysis in water samples N2 - Microplastic detection in water samples becomes important for tracing microplastic sources. Microplastic may harm desalination facilities by blocking filters and disturbing the marine food chain. Thermo analytical methods such as pyrolysis gas chromatography mass spectroscopy, and spectroscopic methods like (micro) Raman spectroscopy or (micro) Fouriertransform infrared spectroscopy in combination with appropriate filters and sample preparation are suitable for analyzing microplastics on a scale from 1 µm to 1000 µm fast and unambiguous. While the thermo analytical methods are suitable for larger sample volumes, Raman spectroscopy and Fouriertransform infrared spectroscopy are able to detect and analyze single microplastic particles for instance in bottled water. Machine learning algorithms ensure a reliable classification of different plastic materials. T2 - International Conference on Sustainable Energy-Water-Environment Nexus in Desert Climate 2019 CY - Ar-Rayyan, Qatar DA - 02.12.2019 KW - Microplastics KW - Water samples PY - 2022 SP - 111 EP - 113 PB - Springer AN - OPUS4-56240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stroh, Julia T1 - High resolution in situ monitoring of the initial cement hydration influenced by organic admixtures N2 - Numerous admixtures are used in the building practice to customize the properties of the cement paste during application. The influences of admixtures on the course of cement hydration and formation of hydrate phases have to be considered. Polycarboxylate ether (PCE) based polymeric superplasticizers (SPs) are known to retard the setting of the cement paste. The extent of the retardation differs depending on the molecular structure of the SP. Additionally, the presence of a stabilizing agent (SA) in the cement paste has a retarding side effect on the setting. The initial cement hydration processes and the detailed mechanisms of the retardation influenced by PCEs, as well as their interactions with particular SAs, are insufficiently understood. Up to now, only the results of phenomenological studies were taken into account to describe this retardation process. A detailed structure analysis monitoring the change of the phase composition during the hydration was never applied. Both SP and SA affect the adsorption of the sulphate ions on the clinker particles, causing changes in the formation of ettringite during the initial hydration, and are therefore a crucial part of the setting process itself. Here, the initial hydration of cement influenced by the interaction of SP and SA was monitored in situ by synchrotron X-ray diffraction. The high time resolution of the measurements allowed a continuous detection of the hydrates formed. The hydration was followed from the starting point of water addition and for couple of hours afterwards. The hydration of the levitated cement pellets containing starch as SA was initialized by adding aqueous solutions of different commercial SPs. Changes in the ettringite formation were detected in comparison to the reference hydration of pure cement. T2 - Early Age Concrete: From the Research Lab to the Construction Site CY - Tomsk, Russia DA - 02.06.2015 KW - Portland cement KW - Initial hydration KW - Superplasticizer KW - Stabilizer KW - Synchrotron XRD PY - 2015 AN - OPUS4-35470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - In situ investigation of mechanochemical syntheses of manganese phosphonates with N-containing ligands N2 - Mechanochemistry is a versatile approach for green and fast synthesis of pure substances. The exploration of the chemistry of metal phosphonates has gained considerable interest during the last decades due to their structural diversity. We synthesized manganese phosphonates in milling reactions. The mechanochemical reactions were investigated in situ to reveal the underlying mechanisms. T2 - Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - In situ KW - Thermography PY - 2018 AN - OPUS4-46999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dittmann, Daniel A1 - Saal, L. A1 - Zietzschmann, F. A1 - Mai, M. A1 - Altmann, Korinna A1 - Al-Sabbagh, Dominik A1 - Ruhl, A. S. A1 - Jekel, M. A1 - Braun, U. T1 - Aktivkohlecharakterisierung als weiterer Schlüssel für Adsorptionsprognosen organischer Spurenstoffe in der vierten Reinigungsstufe N2 - In diesem Beitrag wird der Einfluss des Aktivkohleprodukts auf die Adsorption von Spurenstoffen aus Kläranlagenablauf gezeigt und diskutiert. Im zweiten Teil wird das Material Aktivkohle analytisch charakterisiert und die Eigenschaften systematisiert. Die gewonnenen Erkenntnisse werden mit Bezug zu Praxislösungen zusammengefasst. T2 - Wasser 2021 CY - Online meeting DA - 10.05.2021 KW - Aktivkohle KW - Thermogravimetrie KW - Zersetzungsgasanalyse KW - Proximatanalyse PY - 2021 SP - 373 EP - 378 AN - OPUS4-52740 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peplinski, Burkhard A1 - Adamczyk, Burkart A1 - Formanek, P. A1 - Meyer, Christian A1 - Krüger, O. A1 - Scharf, Holger A1 - Reinsch, Stefan A1 - Ostermann, Markus A1 - Nofz, Marianne A1 - Jäger, Christian A1 - Adam, Christian A1 - Emmerling, Franziska T1 - Nanocrystalline and stacking-disordered beta-cristobalite AlPO4 chemically stabilized at room temperature: synthesis, physical characterization, and X-ray powder diffraction data N2 - This paper reports the first successful synthesis and the structural characterization of nanocrystalline and stacking-disordered β-cristobalite AlPO4 that is chemically stabilized down to room temperature and free of crystalline impurity phases. Several batches of the title compound were synthesized and thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy mapping in SEM, solid-state 31P nuclear magnetic resonance (31P-NMR) spectroscopy including the TRAPDOR method, differential thermal analysis (DTA), gas-sorption methods, optical Emission spectroscopy, X-ray fluorescence spectroscopy, and ion chromatography. Parameters that are critical for the synthesis were identified and optimized. The synthesis procedure yields reproducible results and is well documented. A high-quality XRD pattern of the title compound is presented, which was collected with monochromatic copper radiation at room temperature in a wide 2θ range of 5°–100°. KW - Stabilization of high-temperature phase at RT KW - Nanochrystalline AlPO4 KW - Beta-christobalite structure type KW - High-cristobalite form KW - Aluminium phosphate PY - 2017 DO - https://doi.org/10.1017/S0885715617000537 SN - 1945-7413 SN - 0885-7156 VL - 32 IS - S1 SP - S193 EP - S200 PB - JCPDS-ICDD CY - Cambridge AN - OPUS4-42235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Haferkamp, Sebastian A1 - Emmerling, Franziska T1 - Insights into mechanochemical Knoevenagel condensations N2 - Mechanochemistry paves the way to simple, fast, and green syntheses. Despite considerable effort, there is a lack in understanding of the underlying mechanisms. In situ investigations help to understand these mechanisms, which occur during a mechanochemical reaction. Here we present a universal strategy for simultaneous real-time in situ analysis, combining X-ray diffraction, Raman spectroscopy, and thermography. The potential of of our approach is shown for diffrent model reactions. T2 - Adlershofer Forschungsforum 2019 CY - Berlin, Germany DA - 11.11.2019 KW - Mechanochemistry KW - In situ KW - Knoevenagel condensation PY - 2019 AN - OPUS4-49694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Synthesizing a library of 1000+ reproducible MOFs N2 - While the synthesis of Metal-Organic Framework (MOF) particles can be as easy as adding two solutions together, reproducibly obtaining the same particles, time and time again, is a lot harder. As laboratory-independent reproducibility is a cornerstone of the scientific method, we must put effort into finding and controlling all necessary parameters to achieve this. An open-source Python/EPICS-controlled robotic platform (see picture) was adapted to systematically explore this for a 20 ml MOF synthesis of the Zeolitic Imidazole Framework-8 (ZIF-8) chemistry in methanol. Parameters that were explored included: 1) addition sequence, 2) addition speeds, 3) reaction times, 4) source chemicals, 5) stirring speeds, 6) stirring bar choice, 7) starting concentrations, and 8) workup methodologies. It was found that, by controlling these parameters, highly reproducible syntheses are obtained. Secondly, the variation of these parameters alone led to a dramatic difference in volume-weighted particle size means, which exceeds an order of magnitude as investigated by our in-house X-ray scattering instrument [1]. The syntheses are thoroughly documented in an automated fashion, and the synthesis libraries as well as analyses libraries will become available in batches soon. With this library, it will be possible to extract previously unknown correlations, and other laboratories can produce specific particles by following the exact procedures of the particles of their choice. T2 - 787. WE-Heraeus-Seminar: Accelerated Discovery of New Materials CY - Bad Honnef, Germany DA - 15.05.2023 KW - Metal organic frameworks KW - Automation KW - Lab automation KW - Robotic-supported synthesis KW - Reproducibility KW - Synthesis library KW - X-ray scattering KW - Particle size distribution PY - 2023 AN - OPUS4-57596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Digital Everything: X-ray Scattering and Synthesis Laboratories N2 - In our (dramatically understaffed) X-ray scattering laboratory, developing a systematic, holistic methodology let us provide scattering and diffraction information for more than 2100 samples for 200+ projects led by 120+ collaborators. Combined with automated data correction pipelines, and our analysis and simulation software, this led to more than 40 papers in the last 5 years with just over 2 full-time staff members. This year, our new, modular synthesis platform has made more than 1000 additional samples for us to analyse and catalogue. By virtue of the automation, the synthesis of these samples is automatically documented in excruciating detail, preparing them for upload and exploitation in large-scale materials databases. This talk is intended to spark ideas and invite collaborations by providing an overview of: 1) the current improvements in our wide-range X-ray scattering laboratory methodology, and 2) introducing our open, modular robotic platform for systematic sample preparation. T2 - Seminar at KIT CY - Karlsruhe, Germany DA - 17.08.2023 KW - Lab automation KW - Data stewardship KW - Scattering KW - X-ray scattering KW - Automated synthesis KW - Data pipelines PY - 2023 AN - OPUS4-58234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard A1 - Breßler, Ingo T1 - 30.000+ datasets in an underground SciCat instance: the good, the bad, and the improvables. N2 - For the last four years, we have been running a SciCat instance to manage the projects and data in our X-ray scattering laboratory. We here report on the configuration of this SciCat instance, how it connects to the scientific workflow, and how it is integrated in the data pipeline. T2 - SciCat 2023 CY - Didcot, UK DA - 18.07.2023 KW - Scicat KW - X-ray scattering KW - Laboratory management KW - Research Data Management KW - Laboratory organization KW - RunDeck PY - 2023 AN - OPUS4-57958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - McSAS for SAS analysis: Usage, Benefits and Potential Pitfalls N2 - This talk introduces McSAS, code for analysis of scattering patterns to extract particle size distributions. It highlights how it works, how it should be used, and when it may (not) be applied T2 - Better with Scattering workshop 2020 CY - BAM, Berlin, Germany DA - 16.03.2020 KW - Small angle scattering KW - Software KW - Analysis PY - 2020 AN - OPUS4-51019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chabbah, T. A1 - Chatti, S. A1 - Jaffrezic-Renault, N. A1 - Weidner, Steffen A1 - Marestin, C. A1 - Mercier, R. T1 - Impedimetric sensors based on diethylphosphonate-containingpoly(arylene ether nitrile)s films for the detection of lead ions N2 - This article describes the elaboration and characterization of diethylphosphonate-containing polymers coated electrodes as sensors for the detection of heavy metalstraces, by electrochemical impedance spectroscopy. Diethylphosphonate groupswere chosen as heavy metals binding sites. Two different series of polymers bearingthese anchoring groups were synthesized. Whereas the diethylphosphonate groupsare directly incorporated in the aromatic macromolecular chain in some polymers, analiphatic spacer is removing the chelating site from the polymer backbone in others.The influence of the macromolecular structure on the sensing response was studied,especially for the detection of Pb2+,Ni2+,Cd2+and Hg2+. Polymer P6, including thehigher amount of diethylphosphonate groups removed from the polymer chain by ashort alkyl spacer gave the higher sensitivity of detection of lead ions, with a detec-tion limit of 50 pM KW - Heavy metals KW - Phosphonate esters KW - Lead ions KW - MALDI TOF MS PY - 2023 DO - https://doi.org/10.1002/pat.6065 SN - 1042-7147 SP - 1 EP - 11 PB - John Wiley & Sons, Ltd AN - OPUS4-57356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rösler, Alexander A1 - Weidner, Steffen A1 - Klamroth, Tillmann A1 - Müller, Axel HE A1 - Schlaad, Helmut T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents N2 - AbstractThe kinetics of anionic polymerization of β‐myrcene initiated by sec‐butyllithium were examined in saturated and unsaturated hydrocarbon solvents, i.e. cyclohexane, cyclohexene, 4‐vinylcyclohexene and dl‐limonene. Polymerizations usually proceeded in a living manner, i.e. in the absence of termination and chain transfer reactions, in all solvents, to produce well‐defined polymyrcenes with high content (85%) of cis‐1,4 units. However, polymyrcenyllithium chains exhibited limited long‐term stability in 4‐vinylcyclohexene solution, most probably due to chain transfer to solvent. Reaction orders with respect to the concentration of active chains were found to be one‐quarter in cyclohexane increasing to one‐half in unsaturated solvents, indicating that the polymyrcenyllithium chains are present as tetrameric or dimeric associates, respectively. Apparent activation energies were found to be 81 kJ mol−1 in cyclohexane and 77 kJ mol−1 in dl‐limonene solution, which are close to the values obtained by quantum chemical calculations. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. KW - Myrcene KW - Anionic polymerization KW - MALDI TOF MS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649039 DO - https://doi.org/10.1002/pi.6772 SN - 0959-8103 SP - 1 EP - 8 PB - Wiley AN - OPUS4-64903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gründer, Klaus-Peter A1 - Geburtig, Anja T1 - Optical Methods in Single Crystal Deformation Analysis at High Temperature N2 - This poster deals with grating methods, white light intereference microscopy, a setup for HT investigation and applications. T2 - International Symposium on „Photonics in Measurement“ CY - Aachen, Germany DA - 11.06.2002 KW - Grating method KW - White light intereference microscopy KW - HT investigation PY - 2002 AN - OPUS4-35899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hufgard, Josefin T1 - AIM Forward: Acoustic Ion Manipulation for Efficient Ambient-Pressure Ion Control N2 - In ion-based spectrometry techniques the possibility to manipulate ions is fundamentally important. Currently used ion optics mostly rely on magnetic or electric fields. The electromagnetic forces compete with ion diffusion and are therefore most effective under low-pressure conditions. Therefore, high-pressure ion optics pose challenges related to elevated powers and potentials as well as complex structures and electrode contamination. Acoustic Ion Manipulation (AIM) is a recently discovered phenomenon that relies on the unique interactions between gas-phase ions and acoustic waves. This presentation shows selected patterns of ion manipulation, highlights the flexibility of AIM and discusses its current limitations and potentials. T2 - DGMS Annual Conference 2026 CY - Leipzig, Germany DA - 10.03.2026 KW - Acoustic ion manipulation KW - Mass spectrometry PY - 2026 AN - OPUS4-65680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El Abbassi, Abdelouahad A1 - Krenzer, Julius A1 - Petrov, Eugene P. A1 - Biesen, Lukas A1 - Vasylyeva, Vera A1 - Merzenich, Sarah A1 - Resch-Genger, Ute A1 - Müller, Thomas J. J. T1 - Aroyl-S,N-ketene acetal-triarylamine bichromophores – intramolecular energy transfer and dual emission upon induced aggregation and encapsulation N2 - Aroyl-S,N-ketene acetal-based bichromophores are synthesized by a catalytic aryl amination and their photophysics are studied in the solid state, in ethanol–water mixtures inducing aggregation, and after encapsulation in polystyrene nanoparticles. The dye substitution pattern controls aggregation-induced emission and intramolecular energy transfer efficiency, resulting in single-band or dual fluorescence and a strong increase in fluorescence quantum yield upon particle encapsulation. KW - Fluorescence KW - Dye KW - Aggregation KW - Photophysics KW - Enhancement KW - White light emission KW - Energy transfer KW - Quantum yield PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656700 DO - https://doi.org/10.1039/d5ra09361a SN - 2046-2069 VL - 16 IS - 11 SP - 10255 EP - 10260 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wachtendorf, Volker A1 - Barthel, Anne-Kathrin A1 - Geburtig, Anja A1 - Trubiroha, P. ED - Reichert, T. T1 - Low-Temperature Irradiation Experiments for PE, PA, and PC Matrices N2 - In this paper, we demonstrate the effects of radiation exposures of polymeric materials with UV-A 340 nm lamps (ISO 4892-3, Type 1A) at -10 °C in comparison to an irradiation at +50 °C using a Global UV Test 200 fluorescent lamp device from Weiss Umwelttechnik GmbH, which incorporates an active cooling appliance. While the effects at -10 °C actually are lower than at + 50°C their extent was clearly beyond expectations. T2 - 8th European Weathering Symposium CY - Vienna, Austria DA - 20.09.2017 KW - Artificial weathering KW - Irradiation KW - Low-temperature KW - Photo-oxidation KW - Polyamide KW - Polycarbonate KW - Polyethylene PY - 2017 SN - 978-3-9818507-1-0 VL - 18 SP - Paper 22, 319 EP - 329 PB - Thomas Würtz Grafik Design CY - Karlsruhe AN - OPUS4-42130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute A1 - Krüger, Oliver A1 - Bandow, Nicole A1 - Geburtig, Anja ED - Reichert, Thomas T1 - Laboratory Weathering Test for Simulating the Leaching from Artificial Sporting Grounds N2 - In order to estimating the amount and kind of emissions from polymeric sporting tracks a laboratory test was developed in BAM that combines artificial weathering and subsequent batch and column tests [1, 2, 3]. The goal consisted in nvestigating a possible change of emissions into soil and groundwater of a new sporting ground as a function of ageing and egradation of the system. At various stages of the weathering, the samples were removed and subjected to especially designed column extraction tests for the solid samples. Both these extracts and the accumulated rainwater run-off of the weathering device were subjected to analytical tests of their ingredients. The overall aim of the test consisted in developing ontrollable, reproducible, and standardisable conditions and methods of investigation that would allow an estimation of the emissions in the course of outdoor application of about five years. T2 - 7th European Weathering Symposium. Natural and Artificial Ageing of Polymers CY - Naples, Italy DA - 16.09.2015 KW - artificial weathering KW - emission KW - leaching KW - sporting track KW - degradation KW - ageing KW - rubber KW - extraction PY - 2015 SN - 978-3-9816286-6-1 VL - CEES 17 SP - 195 EP - 208 PB - Thomas Würtz CY - Karlsruhe, Germany AN - OPUS4-35401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - McSAS for SAS analysis: Usage, Benefits and Potential Pitfalls N2 - An introductory lecture for users at the Diamond Light Source, on how to use the McSAS software to analyze their data. T2 - Small Angle Scattering Training School CY - Diamond Light Source, Didcot, United Kingdom DA - 04.06.2018 KW - Small-angle scattering KW - Software KW - Analysis PY - 2018 AN - OPUS4-46517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Battistella, Beatrice A1 - Revill, Adam A1 - Venzago, Cornel A1 - Hoffmann, Volker A1 - Agudo Jácome, Leonardo A1 - Al-Sabbagh, Dominik A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Depth-Resolved Lithium Isotope Fractionation as a Diagnostic of Interphase Evolution and Degradation in Lithium Ion Batteries N2 - Lithium isotopic fractionation is well-established in dynamic geochemical systems; however, its role in lithium-ion batteries (LIBs) remains uninvestigated. Herein, we report the first depth-resolved demonstration that isotopic separation occurs during Li-ion cell operation whose magnitude depends on the cycling history. Using depth-resolved glow discharge mass spectrometry, we monitored the 7Li/6Li ratio in LiNi0.333Mn0.333Co0.333O2 (NMC111)||graphite coin cell electrodes at defined life-cycle stages. Different charging rates were examined to get mechanistic insight into kinetic and thermodynamic control in the fractionation process. Although pristine electrodes exhibit a uniform isotopic ratio, cycled electrodes show a distinct 7Li enrichment in the positive electrode and a corresponding accumulation of 6Li at the surface of the negative electrode. The degree of isotopic separation varies with the charging rate. Isotopic signatures correlate with capacity fading, indicating lithium isotope mapping as a sensitive diagnostic tool for tracking electrode degradation and the evolution of the electrode–electrolyte interphases in LIBs. KW - Li-ion batteries KW - Lithium isotopes KW - Post-mortem analysis KW - GD-MS KW - Depth profile KW - Mass spectrometry PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651287 DO - https://doi.org/10.26434/chemrxiv-2025-5rvlk SP - 1 EP - 19 AN - OPUS4-65128 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Vogl, Jochen A1 - Pritzkow, Wolfgang ED - Vanhaecke, F. ED - Degryse, P. T1 - Reference materials in isotopic analysis N2 - The production of isotopic reference materials (IRMs), which started in the 1960s, has stagnated during the last 15 years. On the other hand, the need for IRMs increased strongly with upcoming ICP-MS techniques, especially with MC instruments, in the beginning of the millennium. In parallel, the precision of the isotope amount ratio determinations reached a level which is beyond that of IRMs certified relying on synthetic isotope mixtures. Additionally, the number of elements for which IRMs are required has increased. This difference between the users’ needs and the limitations of current IRMs can only be solved by providing IRMs defining a δ-scale for each element of interest. Such δ-RMs should be produced as solutions to avoid any complications with homogeneity issues. Whenever possible, isotope amount fractions should be provided additionally, even if the uncertainties are not sufficient for cutting-edge research on isotopic variations. Research should also focus on ways to provide isotope amount fractions with lower uncertainties. For the coming years, around 27 elements have been selected by user communities as "of interest” in this context. These elements are of interest to geo- and cosmochemists, and also to scientists working in the fields of human nutrition, human medicine, veterinary medicine, and food traceability. For 18 elements, such as Pb and U, IRMs or δ-RMs are available, provided as a solution or a solid material with sufficient homogeneity. Nevertheless, in some cases further materials are necessary, because the number of units is too small or the materials are too expensive to be widely accepted by users. At BAM, IRMs and δ-RMs will be produced according to the requirements mentioned above. NIST has also started a program to produce new RMs for δ-values. As discussed at the latest meeting of the IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW) in July 2009 in Vienna, these activities will be supported by IUPAC. KW - ICPMS KW - IRM KW - Reference materials KW - Delta reference materials PY - 2012 SN - 978-3-527-32896-3 SN - 978-3-527-65048-4 DO - https://doi.org/10.1002/9783527650484.ch6 SP - 139 EP - 163 PB - Wiley-VCH CY - Weinheim AN - OPUS4-26102 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tannenberg, Robert A1 - Tscheuschner, Georg A1 - Raab, Christopher A1 - Flemig, Sabine A1 - Döring, Sarah A1 - Ponader, Marco A1 - Thurmann, Melinda A1 - Paul, Martin A1 - Weller, Michael G. T1 - Simplified Sample Preparation and Lateral Flow Immunoassay for the Detection of Plant Viruses N2 - Lateral flow immunoassays (LFAs) are widely used for on-site testing; however, their use for the rapid detection of plant viruses in the field is often limited by inconvenient sample preparation. Here, we present a new sampling method and a simplified dipstick LFA format for the detection and monitoring of cowpea chlorotic mottle virus (CCMV) as a model plant pathogen. The assay employs a monoclonal mouse antibody for capture and a poly-clonal rabbit antibody conjugated to 80 nm gold nanoparticles for detection. Conventional sample and conjugate pads are omitted, allowing the test strips to be dipped directly into wells containing plant extract and antibody–gold conjugate. No plastic casing was required, which could lead to a reduction in waste. It was shown that CCMV concentrations as low as 3.5 µg/L or 350 pg per sample could be reliably detected in 15 min. Specificity tests confirmed that other plant viruses, cowpea mosaic virus (CPMV) and tobacco mosaic virus (TMV), did not produce false-positive results. In addition, we describe a new method for on-site sampling using a manual punch and a syringe equipped with a frit. This step combines grinding the sample, extraction, filtration, and reconstitution and mixing of the antibody-gold conjugate, enabling the analysis of punched leaf disks without laboratory equipment. When applied to CCMV-infected cowpea plants, the assay revealed systemic infection before visual symptoms became apparent. This work demonstrates that simplified LFAs combined with innovative sampling techniques can provide sensitive, specific, and rapid diagnostics for crop monitoring and support early intervention strategies in agriculture. N2 - Lateral-Flow-Immunoassays (LFAs) werden häufig für Vor-Ort-Tests eingesetzt; ihr Einsatz zum schnellen Nachweis von Pflanzenviren im Feld wird jedoch oft durch eine umständliche Probenvorbereitung eingeschränkt. Hier stellen wir eine neue Probenahmemethode und ein vereinfachtes Dipstick-LFA-Format zum Nachweis und zur Überwachung des Cowpea Chlorotic Mottle Virus (CCMV) als Modellpflanzenpathogen vor. Der Test verwendet einen monoklonalen Maus-Antikörper zur Bindung und einen polyklonalen Kaninchen-Antikörper, der an 80-nm-Goldnanopartikel konjugiert ist, zum Nachweis. Herkömmliche Proben- und Konjugatpads entfallen, sodass die Teststreifen direkt in Vertiefungen getaucht werden können, die Pflanzenextrakt und das Antikörper-Gold-Konjugat enthalten. Es ist keine Kunststoffhülle erforderlich, was zu einer Reduzierung des Abfallaufkommens führen könnte. Es zeigte sich, dass CCMV-Konzentrationen von nur 3,5 µg/L oder 350 pg pro Probe innerhalb von 15 Minuten zuverlässig nachgewiesen werden konnten. Spezifitätstests bestätigten, dass andere Pflanzenviren, das Cowpea Mosaic Virus (CPMV) und das Tobacco Mosaic Virus (TMV), keine falsch-positiven Ergebnisse lieferten. Darüber hinaus beschreiben wir eine neue Methode zur Probenahme vor Ort unter Verwendung eines manuellen Lochers und einer mit einer Fritte ausgestatteten Spritze. Dieser Schritt kombiniert das Zerkleinern der Probe, die Extraktion, die Filtration sowie die Rekonstitution und das Mischen des Antikörper-Gold-Konjugats und ermöglicht so die Analyse der ausgestanzten Blattscheiben ohne Laborausrüstung. Bei der Anwendung an mit CCMV infizierten Augenbohnenpflanzen zeigte der Assay eine systemische Infektion, bevor visuelle Symptome erkennbar wurden. Diese Arbeit zeigt, dass vereinfachte LFAs in Kombination mit innovativen Probenahmetechniken eine sensitive, spezifische und schnelle Diagnostik für die Pflanzenüberwachung bieten und Strategien zur frühzeitigen Intervention in der Landwirtschaft unterstützen können. KW - Point-of-care diagnostics KW - Dipstick immunoassay KW - Pre-symptomatic detection KW - Precision agriculture KW - Integrated pest management KW - Crop health monitoring PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657039 DO - https://doi.org/10.3390/bios16020100 SN - 2079-6374 VL - 16 IS - 2 SP - 1 EP - 16 PB - MDPI AG CY - Basle, Switzerland AN - OPUS4-65703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herter, Sven-Oliver T1 - Quantifizierung von Mutterkornalkaloiden in Lebensmitteln unter Verwendung neu entwickelter stabil isotopenmarkierter interner Standards N2 - Mutterkornalkaloide sind Mykotoxine, die von Pilzen der Gattung Claviceps produziert werden und häufig in Roggen- und Weizenprodukten vorkommen. Aufgrund ihrer toxikologischen Relevanz hat die Europäische Union im Jahr 2022 erstmals Grenzwerte für diese Alkaloide in Lebensmitteln eingeführt. Eine zuverlässige Quantifizierung ist essenziell für die Überwachung der Lebensmittelsicherheit. Allerdings stellte der bisherige Mangel an stabilen isotopenmarkierten (SIL - stable isotopically labeled) Standards eine wesentliche Herausforderung für die Entwicklung präziser Analysemethoden mittels HPLC-MS/MS dar. Um diese Lücke zu schließen, wurden erstmals alle zwölf prioritären Mutterkornalkaloide über einen einheitlichen Semisyntheseansatz als 13CD3-markierte Analoga synthetisiert und als interne Standards für die massenspektrometrische Analyse eingesetzt. Die Quantifizierung erfolgte mittels HPLC-MS/MS in verschiedenen Lebensmittelmatrizes, darunter Brot, Roggen- und Weizenmehl sowie Kleie. Zur Evaluierung der SIL-Standards wurden etablierte Methoden wie externe Kalibrierung und Standardaddition herangezogen. Die Studienergebnisse zeigen, dass der Einsatz von SIL-Standards die Genauigkeit und Präzision der Mutterkornalkaloid-Quantifizierung signifikant verbessert. Dies ist insbesondere auf die Korrektur von Matrixeffekten, Extraktions- und Signalschwankungen während der massenspektrometrischen Analyse zurückzuführen. Die neu synthetisierten 13CD3 markierten Mutterkornalkaloide stellen daher ein wertvolles Werkzeug zur Verbesserung der Lebensmittelsicherheit dar, da sie zuverlässigere und reproduzierbare Messergebnisse ermöglichen. Darüber hinaus leisten diese Ergebnisse einen wichtigen Beitrag zur Weiterentwicklung analytischer Methoden zur Überwachung von Mutterkornalkaloiden und damit zur Sicherstellung der Lebensmittelqualität. T2 - 53. Deutsche Lebensmittelchemietage CY - Halle (Saale), Germany DA - 22.09.2025 KW - HPLC-MS/MS KW - Interner Standard KW - Qualitätssicherung PY - 2025 AN - OPUS4-64546 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Thorsten A1 - Goerdeler, Cornelius A1 - El-Khatib, Ahmed H. A1 - Meyer, Klas A1 - Bruer, Gustav G. A1 - Abraham, Klaus A1 - Monien, Bernhard T1 - Characterization and quantitation of urinary metabolites of 3-monochloropropane-1,2-diol (3-MCPD) in rats N2 - Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD) are heat-induced contaminants formed from fats and sodium chloride. The mode of action for the 3-MCPD mediated induction of renal tubule neoplasms in rats is still unclear, which is in part due to lacking metabolism data. In the current study, urinary metabolites were identified by one- and two-dimensional 13C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry following oral administration of 3-MCPD or [13C3]3-MCPD in rats. In addition to 3-MCPD itself, nine metabolites were identified. Four of those, N-acetyl-S-(2,3-dihydroxypropyl)cysteine (DHPMA), 3-MCPD sulfate, β-chlorolactic acid (β-ClLA) and oxalic acid have been reported before. Five novel metabolites in rat urine were thiodiglycolic acid (TDGA), thionyldiglycolic acid (TNDGA), 3-MCPD glucuronide (at least three isomers), 3-carboxy-2-hydroxypropyl mercapturic acid (CHPMA), and 3-(S-carboxymethyl)mercaptolactic acid (CMMLA). Only three metabolites were excreted at mean dose ratios > 1% (after treatment with 50 mg 3-MCPD/kg body weight in male and female rats), i.e. 3-MCPD (7.3%, 9.7%), DHPMA (3.5%, 1.7%) and TDGA (1.1%, 4.0%). The overall mean dose excretion in urine samples (males: 12.2%, females: 16.3%) supported hypotheses on formation of conjugates/adducts of reactive metabolites and the possibility that dechlorination leads to suitable building blocks for amino acid and fatty acid synthesis. The identification of TDGA indicated the interim formation 2-chloroacetaldehyde, previously identified to mediate specific nephrotoxic effects of the cytostatic ifosfamide in rats. KW - 3-Monochloropropane-1,2-diol KW - 3-MCPD KW - Metabolism KW - Urine PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657230 DO - https://doi.org/10.1007/s00204-026-04318-x SP - 1 EP - 17 PB - Springer-Verlag GmbH CY - Heidelberg AN - OPUS4-65723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Altmann, Korinna A1 - Abusafia, A A1 - Bannick, C-G A1 - Braun, U A1 - Crasselt, Claudia A1 - Dittmar, S A1 - Fuchs, M A1 - Gehde, M A1 - Hagendorf, C A1 - Heller, C A1 - Herper, D A1 - Heymann, S A1 - Kerndorff, A A1 - Knefel, M A1 - Jekel, M A1 - Lelonek, M A1 - Lunkenbein, T A1 - Obermaier, N A1 - Manhart, M A1 - Meurer, Maren A1 - Miclea, P-T A1 - Paul, A A1 - Richter, S A1 - Ricking, M A1 - Rohner, C A1 - Ruhl, A A1 - Sakai, Y A1 - Saravia Arzabe, C A1 - Scheid, C A1 - Schmitt, M A1 - Schnarr, M A1 - Schwertfirm, F A1 - Steinmetz, H A1 - Wander, Lukas A1 - Wiesner, Yosri A1 - Zechmeister, L T1 - RUSEKU - Repräsentative Untersuchungsstrategien für ein integratives Systemverständnis von spezifischen Einträgen von Kunststoffen in die Umwelt : Abschlussbericht N2 - Im Verbundprojekt RUSEKU wurde die Probenahme von Wasserproben entscheidend weiterentwickelt. Wichtig ist hierbei zu gewährleisten, dass genügend Merkmalsträger in jeder Probe untersucht werden. Es muss daher eine für den Probenahmeort repräsentative Beprobung hinsichtlich des Wasservolumens in Abhängigkeit der Partikelanzahl gewährleistet sein. Das Hauptaugenmerk lag im vorliegenden Projekt auf einer praxisnahen Beprobungsstrategie. Es wurden verschiedene Konzepte ausprobiert. • Grundsätzlich hat sich gezeigt, dass eine Stichprobe eine Momentaufnahme des MP-Massengehaltes zeigt. Es wird eine hohe Statistik, also eine Vielzahl an Messungen am gleichen Probenahmeort, benötigt, um eine valide Aussage über den MP-Gehalt zu machen. • Es zeigt sich, dass eine integrale Probenahme über mehrere Wochen mit dem SK routinemäßig möglich ist. Die erfassten MP-Massen sind reproduzierbar und robust. • Die DFZ ist für Stichproben geeignet. Partikel < 50 µm werden eventuell unterschätzt • Die fraktionierte Filtration kann für Stich- und Mischproben direkt im Feld genutzt werden. Fraktionen von 10 und 5 µm werden später im Labor Vakuum filtriert. Es erfolgt eine Fraktionierung der Probe mit Siebmaschenweiten von 1000, 500, 100, 50, 10 und 5 µm. • Die fraktionierte Filtration kann auch anschließend an die Beprobung mit dem SK zur Anwendung kommen. Wird die mit dem SK gewonnene Wasserprobe fraktioniert filtriert, kann neben einem MP-Gesamtgehalt auch eine Einschätzung über die Partikelgrößen gewonnen werden. • Für Wässer mit geringen Partikelzahlen wurde ein Messfiltertiegel entwickelt. Dieser hat eine Maschenweite von 6 µm. Seine Anwendung kann mögliche Verluste beim Transferieren vom Probenahmetool zum Messgefäß und mögliche Kontaminationen reduzieren. Die Optimierung der Probenahmestrategie wurde durch Modellversuche und Simulationen unterstützt. Modellversuche zum Sinkverhalten und Simulationen von MP in realen Gewässern verdeutlichten das komplexe Verhalten der Partikel. Es konnte gezeigt werden, dass Partikel ab einer bestimmten Größe (und kleiner) bei genügend starker Turbulenz sich in der Wassersäule unabhängig von ihrer Dichte verhalten und so auch MP mit kleiner Dichte (z.B. PE) in der gesamten Wassersäule zu finden sind. Es konnte mit dem TEM die Existenz von NP gezeigt werden. Ein wesentlicher Aspekt des RUSEKU Projektes war die Beprobung realer Kompartimente. Beprobt wurde neben Oberflächengewässern, das urbane Abwassersystem der Stadt Kaiserslautern, Waschmaschinenabwasser und Flaschenwasser. • In Oberflächengewässern wurde hauptsächlich PE gefunden. Je nach Probe und Gewässer konnten auch PP, PS, PET, PA, SBR und Acrylate nachgewiesen werden. • Im urbanen Abwassersystem der Stadt Kaiserslautern konnte an allen Probenahmestandorten MP nachgewiesen werden. Es wurde hauptsächlich PE, neben geringeren Mengen an PP, PS und SBR gefunden. Nach einem Regenereignis war der SBR Anteil deutlich erhöht. • Die Beprobung eines realen Wäschepostens, bestehend aus T-Shirts und Hemden mit PA/CO oder PES/CO Mischgewebe, zeigte einen PA- und PES-Austrag im Waschwasser. Der überwiegende Teil der detektierten Fasern ist aber auf Baumwolle zurückzuführen. Reine gravimetrische Messungen zur Detektion von MP führen zu einer starken Überschätzung. • In Flaschenwasser (PET-Flaschen) konnte MP detektiert werden. PET wurde nur im stillen Mineralwasser, nicht in Mineralwasser mit Kohlensäure gefunden werden. Teilweise wurde auch das MP-Material des Verschlusses im Wasser detektiert. • Für Luftproben konnte ein Aufbau zur größenselektiven Beprobung getestet werden. Neben der Probenahme hat das Projekt auch gezeigt, dass die TED-GC/MS geeignet für die MP-Detektion im Routinebetrieb ist. Die TED-GC/MS konnte weiter optimiert werden. Es wurden MP-Massen bestimmt. Im Projekt wurden erste realitätsnahe Referenzmaterialien für die MP Detektion hergestellt. Die Herstellung von realitätsnahen Polymeren in ausreichender Homogenität und Menge hat sich als große Herausforderung herausgestellt. KW - Mikroplastik KW - Probennahme KW - TED-GC/MS KW - Fraktionierte Filtration KW - Mikroplastikreferenzmaterial PY - 2022 SP - 1 EP - 201 AN - OPUS4-57800 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ studies of mechanochemistry: a force of synthesis N2 - Recent results in the field of mechanisms and kinetics of mechanochemical reactions. T2 - Seminar GFZ Potsdam CY - Postdam, Germany DA - 28.03.2018 KW - In situ KW - XRD KW - Rietveld PY - 2018 AN - OPUS4-46992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Detektion von Kunststoffen mittels TED-GC-MS N2 - Vortrag zur Funktionsweise der TED-GC-MS für die Analyse von Mikroplastik in Umweltproben T2 - Arbeitsgespräch der Ressortforschungseinrichtungen CY - Berlin, Germany DA - 26.11.2018 KW - Mikroplastik KW - TED-GC-MS PY - 2018 AN - OPUS4-47184 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - New insights in mechanochemical processes using real-time In situ investigations N2 - Mechanochemistry is a fast and efficient method applicable for the synthesis of new organic[1], metal-organic[2], and inorganic[3] compounds. The direct monitoring of milling reactions is still challenging. The underlying reaction mechanisms remain often unclear. In the last years, have established a tandem in situ approach for investigating mechanochemical reactions using time-resolved in situ XRD coupled with Raman spectroscopy.[4] Here, we present an in situ coupling of synchrotron XRD, Raman spectroscopy, and thermography allowing the observation of mechanochemical reactions in real time.[5] Information on the crystalline, molecular, and temperature state of the materials during grinding could be collected. The chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. Furthermore, the presented setup allows the detection of crystalline, amorphous, eutectic as well as liquid intermediates. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. T2 - 5th International Conference "Fundamental Bases of Mechanochemical Technologies" CY - Novosibirsk, Russia DA - 25.06.2018 KW - Mechanochemistry KW - XRD KW - Kinetic KW - Coordination polymers PY - 2018 AN - OPUS4-46994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - Mechanochemical synthesis of metal phosphonates N2 - The exploration of metal phosphonates chemistry has gained great interest during the last decades, because of their structural diversity. Transition metal phosphonates are promising candidates for an application as electrocatalysts in oxygen evolution reactions (OER). Here, we present the in situ investigation of mechanochemical syntheses of different manganese phosphonates by synchrotron X-ray diffraction. Nitrilotri(methylenephosphonic acid) and N,N-Bis(phosphonomethyl)glycine were chosen as ligands. The liquid-assisted milling process can be divided into three steps, including an amorphous stage. One of the products has not been obtained by classical solution chemistry before. These metal phosphonates and/or their derivatives are considered to be active in electrochemical energy conversion. The verification of their applicability is one of the topics of our resent research. T2 - Fundamental Bases of Mechanochemical Technologies CY - Novosibirsk, Russia DA - 25.06.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - Thermography PY - 2018 AN - OPUS4-46996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Akhmetova, Irina T1 - In situ investigation of milling reactions and structure determination of the products using X-ray diffraction N2 - Mechanochemistry is a versatile approach for green and fast synthesis of pure substances. By milling the reactants, various organic, inorganic, and metal-organic compounds can be obtained in high yields. Although mechanochemistry is widely used, the underlying mechanisms are not fully understood making mechanochemical reactions difficult to predict. Metal phosphonates are metal-organic compounds accessible by grinding. Because of their structural diversity, the exploration of the chemistry of metal phosphonates has gained considerable interest during the last decades. Transition metal phosphonates are promising candidates for an application as electrocatalysts in oxygen evolution reaction (OER). Here, we present the in situ investigation of the mechanochemical synthesis of a manganese(II)-phosphonate by synchrotron X-ray diffraction and thermography. The product has not been obtained by classical solution chemistry before and its crystal structure was determined from PXRD data. The milling process can be divided into different steps, with the product crystallization corresponding with the highest temperature rise. The activity of this metal phosphonate towards OER was measured and is presented here. T2 - International School of Crystallography - 52nd Course: Quantum Crystallography CY - Erice, Italy DA - 1.06.2018 KW - Metal phosphonates KW - Mechanochemistry KW - PXRD KW - OER KW - Thermography PY - 2018 AN - OPUS4-46998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lauer, Franziska A1 - Diehn, Sabrina A1 - Seifert, Stephan A1 - Kneipp, Janina A1 - Sauerland, V. A1 - Barahona, C. A1 - Weidner, Steffen T1 - Multivariate analysis of MALDI imaging mass spectrometry data of mixtures of single pollen grains N2 - Mixtures of pollen grains of three different species (Corylus avellana, Alnus cordata, and Pinus sylvestris) were investigated by matrixassisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF imaging MS). The amount of pollen grains was reduced stepwise from > 10 to single pollen grains. For sample pretreatment, we modified a previously applied approach, where any additional extraction steps were omitted. Our results show that characteristic pollen MALDI mass spectra can be obtained from a single pollen grain, which is the prerequisite for a reliable pollen classification in practical applications. MALDI imaging of laterally resolved pollen grains provides additional information by reducing the complexity of the MS spectra of mixtures, where frequently peak discrimination is observed. Combined with multivariate statistical analyses, such as principal component analysis (PCA), our approach offers the chance for a fast and reliable identification of individual pollen grains by mass spectrometry. KW - MALDI Imaging MS KW - Pollen grains KW - Multivariate Statistics KW - Hierarchical cluster analysis KW - Principal component analysis PY - 2018 DO - https://doi.org/10.1007/s13361-018-2036-5 SN - 1044-0305 SN - 1879-1123 VL - 29 IS - 11 SP - 2237 EP - 2247 PB - Springer AN - OPUS4-45607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Glimpses of the Future : Oh my god it’s full of metadata! N2 - In this talk, the importance of metadata is underscored by real-world examples. Metadata is essential to alleviating the reproducibility crises in science. This imples that a wide range of metadata must be collected, with a heavy emphasis on the automated collection of such metadata. This must subsequently be organized in an intelligible, archival structure, when possible with units and uncertainties. Such metadata can aid in improving the usage efficiency of instrumentation, as is demonstrated on the MOUSE instrument. This metadata can now be used to connect the various aspects of the holistic experimental procedure to gain better insights on the materials structure. A second example shows the extraction and organization of such metadata from an automated materials development platform, collected during the synthesis of 1200 samples. These metadata from the synthesis can then be linked to the results from the analysis of these samples, to find direct correlations between the synthesis parameters and the final structure of the materials. T2 - Helmholtz Incubator Summer Academy - Next Level Data Science CY - Online meeting DA - 18.09.2023 KW - Metadata KW - Lab automation KW - Data provenance KW - High-throughput KW - Correlative analysis KW - MOUSE KW - X-ray scattering KW - Robotics PY - 2023 AN - OPUS4-58463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Laskina, Sofya A1 - Naik, Aakash A1 - Smales, Glen Jacob A1 - George, Janine A1 - Breßler, Ingo A1 - Benner, Philipp T1 - Jupyter notebook and VASP calculation details accompanying the manuscript: "Ultima Ratio: Simulating wide-range X-ray scattering and diffraction" N2 - Summary: This notebook and associated datasets (including VASP details) accompany a manuscript available on the ArXiv (https://doi.org/10.48550/arXiv.2303.13435) and hopefully soon in a journal as short communication as well. Most of the details needed to understand this notebook are explained in that paper with the same title as above. For convenience, the abstract is repeated here: Paper abstract: We demonstrate a strategy for simulating wide-range X-ray scattering patterns, which spans the small- and wide scattering angles as well as the scattering angles typically used for Pair Distribution Function (PDF) analysis. Such simulated patterns can be used to test holistic analysis models, and, since the diffraction intensity is presented coupled to the scattering intensity, may offer a novel pathway for determining the degree of crystallinity. The "Ultima Ratio" strategy is demonstrated on a 64-nm Metal Organic Framework (MOF) particle, calculated from $Q<0.01$\,$\mathrm{nm}^{-1}$ up to $Q\approx150$\,$\mathrm{nm}^{-1}$, with a resolution of 0.16\,\AA. The computations exploit a modified 3D Fast Fourier Transform (3D-FFT), whose modifications enable the transformations of matrices at least up to $8000^3$ voxels in size. Multiple of these modified 3D-FFTs are combined to improve the low-$Q$ behaviour. The resulting curve is compared to a wide-range scattering pattern measured on a polydisperse MOF powder. While computationally intensive, the approach is expected to be useful for simulating scattering from a wide range of realistic, complex structures, from (poly-)crystalline particles to hierarchical, multicomponent structures such as viruses and catalysts. KW - X-ray KW - Simulation KW - Scattering KW - MOUSE KW - Nanomaterials KW - XRD KW - SAXS KW - PDF KW - Total scattering KW - 3D Fourier transform KW - High resolution KW - FFT PY - 2023 DO - https://doi.org/10.5281/zenodo.7764044 PB - Zenodo CY - Geneva AN - OPUS4-57207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Döring, Sarah A1 - Wulfes, Birte S. A1 - Atanasova, Aleksandra A1 - Jaeger, Carsten A1 - Walzel, Leopold A1 - Tscheuschner, Georg A1 - Flemig, Sabine A1 - Gawlitza, Kornelia A1 - Feldmann, Ines A1 - Konthur, Zoltán A1 - Weller, Michael G. T1 - Corundum Particles as Trypsin Carrier for Efficient Protein Digestion N2 - Reusable enzyme carriers are valuable for proteomic workflows, yet many supports are expensive or lack robustness. This study describes the covalent immobilization of recombinant trypsin on micrometer-sized corundum particles and assesses their performance in protein digestion and antibody analysis. The corundum surface was cleaned with potassium hydroxide, silanized with 3-aminopropyltriethoxysilane and activated with glutaraldehyde. Recombinant trypsin was then attached, and the resulting imines were reduced with sodium cyanoborohydride. Aromatic amino acid analysis (AAAA) estimated an enzyme loading of approximately 1 µg/mg. Non-specific adsorption of human plasma proteins was suppressed by blocking residual aldehydes with a Tris-glycine-lysine buffer. Compared with free trypsin, immobilization shifted the temperature optimum from 50 to 60 °C and greatly improved stability in 1 M guanidinium hydrochloride. Activity remained above 80% across several reuse cycles, and storage at 4 °C preserved functionality for weeks. When applied to digesting the NISTmAb, immobilized trypsin provided peptide yields and sequence coverage comparable to soluble enzyme and outperformed it at elevated temperatures. MALDI-TOF MS analysis of Herceptin digests yielded fingerprint spectra that correctly identified the antibody and achieved 60% sequence coverage. The combination of low cost, robustness and analytical performance makes corundum-immobilized trypsin an attractive option for research and routine proteomic workflows. N2 - Wiederverwendbare Enzymcarrier sind für proteomische Arbeitsabläufe von großem Wert, doch viele Trägermaterialien sind teuer oder nicht robust genug. Diese Studie beschreibt die kovalente Immobilisierung von rekombinantem Trypsin auf mikrometergroßen Korundpartikeln und bewertet deren Leistungsfähigkeit beim Proteinverdau und der Antikörperanalyse. Die Korundoberfläche wurde mit Kaliumhydroxid gereinigt, mit 3-Aminopropyltriethoxysilan silanisiert und mit Glutaraldehyd aktiviert. Anschließend wurde rekombinantes Trypsin gebunden, und die entstandenen Imine wurden mit Natriumcyanoborhydrid reduziert. Die aromatische Aminosäureanalyse (AAAA) ergab eine geschätzte Enzymbeladung von etwa 1 µg/mg. Die unspezifische Adsorption von menschlichen Plasmaproteinen wurde durch Blockierung der restlichen Aldehyde mit einem Tris-Glycin-Lysin-Puffer unterdrückt. Im Vergleich zu freiem Trypsin verschob die Immobilisierung das Temperaturoptimum von 50 auf 60 °C und verbesserte die Stabilität in 1 M Guanidiniumhydrochlorid erheblich. Die Aktivität blieb über mehrere Wiederverwendungszyklen hinweg bei über 80 %, und die Lagerung bei 4 °C bewahrte die Funktionalität über Wochen hinweg. Beim Verdau des NISTmAb lieferte das immobilisierte Trypsin Peptidausbeuten und Sequenzabdeckungen, die mit denen des löslichen Enzyms vergleichbar waren, und übertraf dieses bei erhöhten Temperaturen. Die MALDI-TOF-MS-Analyse von Herceptin-Verdauen ergab Fingerabdruck-Spektren, die den Antikörper korrekt identifizierten und eine Sequenzabdeckung von 60 % erreichten. Die Kombination aus niedrigen Kosten, Robustheit und analytischer Leistungsfähigkeit macht auf Korund immobilisiertes Trypsin zu einer attraktiven Option für die Forschung und routinemäßige proteomische Arbeitsabläufe. KW - Bottom-up proteomics KW - Solid-phase digestion KW - Biopharmaceutical analysis KW - Peptide mapping KW - Non-specific binding KW - amino acid analysis PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657021 DO - https://doi.org/10.3390/biotech15010002 SN - 2673-6284 VL - 15 IS - 1 SP - 1 EP - 23 PB - MDPI CY - Basel AN - OPUS4-65702 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Singh, Chandan T1 - Oxidation resistant, interlaced 3D MXene composite for electrochemical biosensing N2 - BSA (Bovine Serum Albumin) as an oxidation resistant for Ti₃C₂Tx-MXene : BSA derived method protects 3D interlaced Ti₃C₂Tx–CNT nanocomposite from oxidative degradation, preserving their structural integrity . Application in biosensing: After the removal of excess BSA, the nanocomposite were amino-silane functionalized and decorated with anti-SARS-CoV-2 antibodies, enabling selective detection of SARS-CoV-2 nucleocapsid protein (SNP) in saliva. Performance of the biosensor: The designed biosensor showed high sensitivity (LoD 23.6 pM), wide detection range (0.1–500 ng/mL), no cross-reactivity, and improved response due to the preserved 3D interwoven nanostructure. T2 - Graphene Week 2025 CY - Vicenza, Italy DA - 22.09.2025 KW - Nanocomposite KW - Biosensor KW - SARS-CoV-2 PY - 2025 AN - OPUS4-65728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kumari, Surbhi T1 - Tagetes erecta synthesized bimetallic Ag–Au nanoparticles and their potential application in electrochemical detection and estimation of ampicillin in raw milk N2 - This study focuses on the green synthesis of Ag–Au nanoparticles using Tagetes erecta extract and their potential application in electrochemical detection and estimation of ampicillin in raw milk. The Ag–Au nanoparticles were covalently bonded to the hydroxylated fluorine-doped tin oxide electrode surface through silane chemistry enabling the effective interaction of the 5' thiolated-aptamer with the nanoparticle-modified surface for aptasensor development. The aptasensor displayed a limit of detection of 0.40 ng mL−1 and a stability of 30 days. Moreover, the aptasensor demonstrated reliable performance with both spiked milk samples and real milk samples, detecting a concentration of 194 ng mL−1 in raw milk with results closely matching with those obtained by the LC-MS technique. T2 - SALSA Make & Measure 2025: Interfaces CY - Berlin, Germany DA - 10.09.2025 KW - Aptamer KW - Antibiotic KW - Biosensing PY - 2025 AN - OPUS4-65727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Klas T1 - Benchtop NMR-Spektroskopie im industriellen Produktionsumfeld: Herausforderungen auf dem Weg zur Online-Prozessintegration N2 - Benchtop-NMR Spektrometer erobern erfolgreich seit Jahren die Labore und haben sich als ein vielseitiges analytisches Werkzeug etabliert. Zunächst stark fokussiert auf den Forschungs-bereich, sind sie heute zunehmend auch nahe der Produktion auf dem Vormarsch. Die Zielstellung ist nur selten der Ersatz von klassischer „Hochfeld“-NMR-Spektroskopie. Vielmehr erschließen die kompakten Geräte oftmals neue Anwendungsfelder, beispielsweise in der Online-Reaktionsverfolgung im Labor oder der schnellen at-line Qualitätskontrolle in der chemischen Produktion. Hier kommen die Vorteile der geringeren Anschaffungs- und Betriebskosten, die Möglichkeit des prozessnahen Einsatzes, sowie besonders der einfachen Bedienung zum Tragen. Während es zahlreiche Beispiele von Online-Applikationen im Labor gibt, ist die direkte Einbindung in großtechnische Produktionsanlagen bislang selten. Im Vergleich zu etablierten prozessanalytischen Verfahren, wie z.B. der Nahinfrarot- oder Raman-Spektroskopie ist die Benchtop-NMR-Spektroskopie noch Neuland und es existieren kaum prozesstaugliche kommerzielle Lösungen. Im Rahmen eines gemeinsamen Entwicklungsprojekts zwischen BAM und Evonik wurde eine Einhausung für ein handelsübliches Benchtop-NMR-Spektrometer konzipiert und gebaut. Diese dient nicht nur der Erfüllung sicherheitstechnischer Auflagen wie dem Explosionsschutz, sondern auch der Abschirmung rauer Umgebungseinflüsse auf den Betrieb des Laborgeräts. Eine flexible integrierte Automatisierung ermöglicht die skalierbare Anbindung an übergeordnete Prozessleittechnik im Sinne eines PAT-Moduls. Dieser Vortrag gibt einen Überblick über die Herausforderungen auf dem Weg von der Idee, über die Umsetzung bis hin zur tatsächlichen Prozessintegration. T2 - 47. Praktische Probleme der Kernresonanzspektroskopie CY - Göttingen, Germany DA - 17.03.2026 KW - Prozessanalytik KW - NMR Spektroskopie KW - Feldintegration KW - Explosionsschutz PY - 2026 AN - OPUS4-65705 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pérez-Padilla, Víctor A1 - Burnage, Samual C. A1 - Wittwer, Philipp A1 - Valderrey, Virginia A1 - Bell, Jérémy A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Detection of Perfluoroalkylic Acids From Water Using a Guanidine-Based Fluorescent Probe and Microfluidic Droplet Extraction N2 - Perfluoroalkylic acids (PFAAs), a subclass of per- and polyfluoroalkyl substances (PFAS), are stable, widely used industrial compounds posing environmental concerns due to their persistence and toxicity. Regulatory actions and remediation strategies necessitate effective onsite analytical methods for PFAS management. We developed an optical sensing system using a fluorescent probe with a benzoxadiazole core and guanidine receptor in a droplet-based microfluidic assay to detect PFAAs in water samples with low detection limits. The PFAAs binding enhances the probe's fluorescence in organic media through protonation-mediated hydrogen bond-assisted ion pairing, exploiting two complementary supramolecular forces. Direct detection employs a liquid-liquid extraction protocol in the microfluidic device, achieving detection limits for PFOA and PFOS down to ≥0.5 µm, with a dynamic range up to 200 µm for sample volumes <100 µL. HCl/KCl buffering facilitates analyte desalting and phase transfer for quantitation from surface water. Additionally, we developed a method involving a thin polymer layer of the probe and a crosslinker on submicron silica particles for direct detection of PFAAs in water. Our approaches provide sensitive, direct recognition and indication of PFAAs, advancing the field beyond indirect sensing and offering improved background suppression, rapid assay times, and a modular design for targeting other PFAS subclasses. KW - PFAS KW - Fluorescence KW - Microfluidics KW - Droplet Extraction PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657330 DO - https://doi.org/10.1002/adsr.70145 VL - 5 IS - 3 SP - 1 EP - 13 PB - Wiley-VCH CY - Weinheim AN - OPUS4-65733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Devi, Sarita A1 - Goel, S. A1 - Rani, S. A1 - Schneider, Rudolf J. A1 - Rohilla, R. A1 - Kumari, Surbhi A1 - Prabhakar, N. T1 - MOF-metal nanohybrid-assisted charge transfer amplification for electrochemical biosensing of the MUC1 cancer biomarker N2 - Cancer is a severe disease characterized by high mortality and complex pathophysiology; however, its early and accurate diagnosis remains inadequate. Conventional diagnostic approaches often fall short, particularly for dense tissues, and are frequently invasive, costly, and of limited availability. This reinforces the need for a compact, economical, and ultrasensitive assay that is operationally simple and interpretable. We present an efficient electrochemical detection platform for the cancer biomarker mucin 1 (MUC1). A fluorine-doped tin oxide (FTO) surface was modified with an iron-based metal–organic framework (FeMOF) intercalated with palladium nanorods (PdNR). FeMOF was prepared using Fe3+/Fe2+ precursors at a 1.2/1 mmol ratio and dual ligands, i.e. tetrahydroxy-1,4-benzoquinone and 2-aminobenzene-1,4-dicarboxylic acid. AntiMUC1 antibodies were immobilized on a modified electrode via p-phenylenediamine (PDA) (FTO/FeMOF@PdNR/PDA/antiMUC1Ab) and evaluated using electrochemical impedance spectroscopy (EIS) and voltammetry. The designed sensor demonstrated an excellent binding affinity for the MUC1 antigen. Among these techniques, the EIS method stands out for its technical performance, as evidenced by the high sensitivity (detection limit 0.074 fg mL−1), quantification limit 0.24 fg mL−1, and high analytical sensitivity (1.39 × 103 Ω fg−1 mL−1 cm−2). The negligible cross-reactivity with interferent biomolecules, rapid response (10-minute equilibrium), regenerability up to 5 cycles, high reproducibility (RSD ∼1–3%), and long-term stability (up to 35 days) further validate the suitability of the proposed MUC1 immunosensor. This study presents an ultrasensitive biosensor that is compact, cost-effective, and easy for individuals at home to use after further development into a kit-based end product. Moreover, its excellent functionality for spiked serum samples shows promise for next-generation clinical diagnostics. KW - Antibodies KW - Metal-organic framework KW - Immunoassay PY - 2026 DO - https://doi.org/10.1039/D6AN00018E SP - 1 EP - 11 PB - Royal Society of Chemistry CY - London AN - OPUS4-65726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sötebier, Carina A1 - Bierkandt, Frank A1 - Rades, Steffi A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Sample loss in asymmetric flow field-flow fractionation coupled to inductively coupled plasma-mass spectrometry of silver nanoparticles N2 - In this work, sample losses of silver nanoparticles (Ag NPs) in asymmetrical flow field-flow fractionation (AF4) have been systematically investigated with the main focus on instrumental conditions like focusing and cross-flow parameters as well as sample concentration and buffer composition. Special attention was drawn to the AF4 membrane. For monitoring possible silver depositions on the membrane, imaging laser ablation coupled to inductively coupled plasma mass spectrometry (LA-ICP-MS) was used. Our results show that the sample residue on the membrane was below 0.6% of the total injected amount and therefore could be almost completely avoided at low sample concentrations and optimized conditions. By investigation of the AF4 flows using inductively coupled plasma mass spectrometry (ICP-MS), we found the recovery rate in the detector flow under optimized conditions to be nearly 90%, while the cross-flow, slot-outlet flow and purge flow showed negligible amounts of under 0.5%. The analysis of an aqueous ionic Ag standard solution resulted in recovery rates of over 6% and the ionic Ag content in the sample was found to be nearly 8%. Therefore, we were able to indicate the ionic Ag content as the most important source of sample loss in this study. KW - Asymmetric flow filed-flow fractionation KW - ICP-MS KW - Nanoparticles KW - Sample loss KW - Quantification PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-336171 DO - https://doi.org/10.1039/c5ja00297d SN - 0267-9477 SN - 1364-5544 VL - 30 IS - 10 SP - 2214 EP - 2222 PB - Royal Society of Chemistry CY - London AN - OPUS4-33617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fink, Friedrich A1 - Emmerling, Franziska A1 - Falkenhagen, Jana T1 - Identification and Classification of Technical Lignins by means of Principle Component Analysis and k-Nearest Neighbor Algorithm N2 - The characterization of technical lignins is a key step for the efficient use and processing of this material into valuable chemicals and for quality control. In this study 31 lignin samples were prepared from different biomass sources (hardwood, softwood, straw, grass) and different pulping processes (sulfite, Kraft, organosolv). Each lignin was analysed by attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy. Statistical analysis of the ATR-FT-IR spectra by means of principal component analysis (PCA) showed significant differences between the lignins. Hence, the samples can be separated by PCA according to the original biomass. The differences observed in the ATR-FT-IR spectra result primarily from the relative ratios of the p-hydroxyphenyl, guaiacyl and syringyl units. Only limited influence of the pulping process is reflected by the spectral data. The spectra do not differ between samples processed by Kraft or organosolv processes. Lignosulfonates are clearly distinguishable by ATR-FT-IR from the other samples. For the classification a model was created using the k-nearest neighbor (k NN) algorithm. Different data pretreatment steps were compared for k=1…20. For validation purposes, a 5-fold cross-validation was chosen and the different quality criteria Accuracy (Acc), Error Rate (Err), Sensitivity (TPR) and specificity (TNR) were introduced. The optimized model for k=4 gives values for Acc = 98.9 %, Err = 1.1 %, TPR = 99.2 % and TNR = 99.6 %. KW - Classification KW - PCA KW - K-nearest neighbor KW - FT-IR KW - Technical lignin PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533855 DO - https://doi.org/10.1002/cmtd.202100028 VL - 1 IS - 8 SP - 350 EP - 396 PB - Wiley-VCH GmbH AN - OPUS4-53385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen T1 - ROP of L-lactide and ε-caprolactone catalyzed by tin(ii) andtin(iv) acetates–switching from COOH terminated linear chains to cycles N2 - The catalytic potential of tin(II)acetate, tin(IV)acetate, dibutyltin-bis-acetate and dioctyl tin-bis-acetate was compared based on polymerizations of L-lactide conducted in bulk at 160 or 130°C. With SnAc2 low-Lac/Cat ratios (15/1–50/1) were studied and linear chains having one acetate and one carboxyl end group almost free of cyclics were obtained. Higher monomer/catalyst ratios and lower temperatures favored formation of cycles that reached weight average molecular weights (Mw's) between 100,000 and 2,500,000. SnAc4 yielded mixtures of cycles and linear species under all reaction conditions. Dibutyltin- and dioctyl tin bis-acetate yielded cyclic polylactides under most reaction conditions with Mw's in the range of 20,000–80,000. Ring-opening polymerizations performed with ε-caprolactone showed similar trends, but the formation of COOH-terminated linear chains was significantly more favored compared to analogous experiments with lactide. The reactivity of the acetate catalysts decreased in the following order: SnAc2> SnAc4>Bu2SnAc2~Oct2SnAc2 KW - Polylactide KW - MALDI-TOF MS KW - Catalyst KW - Ring-opening polymerization KW - Tin acetates PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521923 DO - https://doi.org/10.1002/pol.20200866 VL - 59 IS - 5 SP - 439 EP - 450 PB - Wiley Online Library AN - OPUS4-52192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Scheliga, F. A1 - Weidner, Steffen T1 - What does conversion mean in polymer science? N2 - The definition of the term “conversion” is discussed for a variety of polymer syntheses. It is demonstrated that in contrast to organic and inorganic chemistry several different definitions are needed in polymer science. The influence of increasing conversion on structure and topology of homo- and Copolymers is illustrated. Chain-growth polymerizations, such as radical polymerization or living anionic polymerizations of vinyl monomers, condensative chain polymerization, two and three-dimensional step-growth polymerizations, ring–ring or chain–chain equilibration and chemical modification of polymers are considered. KW - Polymers KW - Polymerization KW - Conversion KW - Polycondensation PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523597 DO - https://doi.org/10.1002/macp.202100010 VL - 222 IS - 8 SP - 10 PB - Wiley VCH AN - OPUS4-52359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen T1 - H2O-Initiated Polymerization of L-Lactide N2 - Water-initiated ring-opening polymerizations (ROPs) of L-lactide (LA) were performed in bulk at 140 °C, whereupon 11 different salts or complexes of low-toxic metal ions such as tin (II), Zn(II), Zr(IV), and Bi(III) were used as catalysts. Only four catalysts gave satisfactory results despite a long reaction time (24 h). The influence of the temperature was studied with tin (II) 2-ethylhexanoate (SnOct2), dibutyltin oxide (Bu2SnO), and zinc bis-acetylacetonate (Zn(acac)2) and zirconium acetylacetonate (Zr(acac)4). With SnOct2, Bu2SnO and Zr(acac)4 the time was varied at 140 °C to compare their reactivity. Furthermore, two series of ROPs were carried out with variation of the LA/H2O ratio to verify the control of the molecular weight by the monomer-initiator ratio. Bi- or tri-modal molecular weight distributions (MWD) were found for most of the ROPs and bimodal melting endotherms in the differential scanning calorimetry (DSC) heating traces. The thickness and dependence of the 3D packing of the crystallites were monitored by small-angle X-ray scattering (SAXS) measurements. KW - MALDI-TOF MS KW - Polylactide KW - Ring-opening polymerization KW - Crystallization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628761 DO - https://doi.org/10.1007/s10924-025-03565-w SN - 1572-8919 VL - 33 IS - 6 SP - 2843 EP - 2857 PB - Springer Science and Business Media LLC CY - New York, NY AN - OPUS4-62876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Scheliga, Felix A1 - Kricheldorf, Hans R. T1 - Polycondensation, Cyclization and Disproportionation of Solid Poly(L-lactide) Trifluoroethyl Esters and the Simultaneous Formation of Extended Chain Crystals and Extended Ring Crystals N2 - Two poly(L-lactide)s (PLAs) with a degree of polymerization (DP) of 20 or 100 were prepared by trifluoroethanol-initiated ring-opening polymerization (ROP) catalyzed by tin(II) 2-ethyl hexanoate (SnOct2). These PLAs were annealed at 140 ◦C or at 160 ◦C in the presence of SnOct2, and the changes in topology and molecular weight distribution (MWD) were monitored by matrix-assisted laser desorption/ionization time-of flight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC). For the PLA with a DP 20, the main reaction was polycondensation combined with higher dispersities. In the case of the DP 100, PLA polycondensation was combined with disproportionation and the formation of a new MWD maximum around m/z 3500. In addition, extensive cyclization occurred, and the resulting cyclic PLAs crystallized separately from the linear chains in the form of extended ring crystals. These results also suggest that both extended chain and extended ring crystals posses the same crystal thickness as a result of thermodynamically controlled transesterification in the solid state. KW - Polycondensation KW - MALDI KW - Polylactide KW - Cyclization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-616441 DO - https://doi.org/10.1016/j.polymer.2024.127800 VL - 315 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-61644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falkenhagen, Jana A1 - Dalgic, Mete-Sungur A1 - Weidner, Steffen T1 - Quantitative MALDI-TOF Mass Spectrometry of Star-Shaped Polylactides Based on Chromatographic Hyphenation N2 - The end groups of three- and four-arm star-shaped polylactides (PLA) with trimethylolpropane and pentaerythritol core structures were functionalized with acetic acid. Reaction products with different degrees of functionalization were analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Additional gradient elution liquid adsorption chromatography (GELAC) measurements were performed to determine the degree of functionalization. This technique enabled clear separation and sufficient quantification of the formed species. These chromatographic data could be used inversely to quantify mass spectrometric results, which are usually biased by the unknown ionization probabilities of different polymer end group structures. Our results showed that, in this particular case, the peak intensity in the MALDITOF mass spectra can be used to semiquantitatively determine the degree of functionalization in incompletely functionalized multiarm PLA. KW - Polylactides KW - MALDI-TOF-MS KW - Gradient elution liquid adsorption chromatography PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625292 DO - https://doi.org/10.1021/jasms.4c00491 SN - 1879-1123 SP - 1 EP - 9 PB - American Chemical Society (ACS) AN - OPUS4-62529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, Hans R. A1 - Weidner, Steffen A1 - Scheliga, Felix T1 - Polycondensation of L-lactic acid: a deeper look into solid state polycondensation N2 - L-Lactic acid (LA) was condensed in the presence of SnCl2 or 4-toluenesulfonic acid (TSA) at 140 °C, and chain growth without cyclization was observed. In addition, poly(L-lactic acid)s (PLAs) with a degree of polymerization (DP) of 25, 50 or 100 were prepared by water-initiated ring-opening polymerization (ROP). These PLAs were annealed in the solid state at 140 °C and 160 °C in the presence of tin(II) 2-ethylhexanoate (SnOct2, SnCl2 or TSA). The changes in the molar mass distribution and in the topology were characterized by means of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and size exclusion chromatography (SEC). With increasing time, fewer side reactions caused higher molar masses and increasing fractions of cyclic polylactides (cPLA) were obtained. Their “saw tooth” pattern in the MALDI-TOF mass spectra indicated the formation of extended ring crystallites in the solid state. TSA was the most active catalyst and caused fewer side reactions than SnCl2, which was the least reactive catalyst. Acetylation of the CH-OH end groups hindered polycondensation and prevented the formation of cPLAs. Reaction mechanisms will be discussed. KW - MALDI-TOF MS KW - Polycondensation KW - Polylaktide KW - Solid state PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625271 DO - https://doi.org/10.1039/d4py01191k SN - 1759-9962 SP - 1 EP - 9 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. A1 - Weidner, Steffen A1 - Meyer, A. T1 - About alcohol-initiated polymerization of glycolide and separate crystallization of cyclic and linear polyglycolides N2 - Alcohol-initiated polymerizations of glycolide (GL) catalyzed by tin(II) 2-ethylhexanoate (SnOct2) were carried out in bulk with variation of GA/In ratio, temperature and time. Due to a rather strong competition of cyclization polyglycolide (PGA) free of cycles were never obtained. When the cyclic catalysts 2,2-dibutal-2-stanna − 1,3-dithiolane (DSTL) or 2-stanna 1,3-dioxo-4,5,6,7 bibenzepane (SnBiph) were used in combination with 1,4-butanediol the influence of cyclization was even stronger. Furthermore, the degrees of polymerization were higher than the GA/alcohol ratio due to rapid polycondensation in the solid state. At 160 °C or below, the matrixassisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra indicated separate crystallization of low molar mass cyclic and linear PGAs from the same reaction mixture (also observed for poly(L-lactide)s). KW - MALDI TOF MS KW - Polyglycolide KW - Ring opening polymerization KW - Cyclization KW - Crystallization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607282 DO - https://doi.org/10.1016/j.polymer.2024.127440 SN - 0032-3861 VL - 309 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-60728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen T1 - Syntheses of cyclic polylactides and the problem of catenane formation N2 - Cyclic poly(L-lactide)s (PLAs) were prepared in bulk either by ring-expansion polymerization (REP) or by ring-opening polymerization (ROP) with simultaneous polycondensation (ROPPOC). In contrast to REP the latter method involves formation of linear chains and thus, may involve formation of polydisperse catenanes that affect crystallization. The reprecipitated PLAs were annealed at 120 °C and compared with regard to melting temperature (Tm) and melting enthalpy (ΔHm). For similar molar masses the PLAs prepared by REP and ROPPOC had almost identical Tm's and crystallinities. Furthermore, the influence of REP and ROPPOC catalysts on the morphology of the virgin reaction products was compared. KW - MALDI-TOF MS KW - Catenane KW - Polylactide PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625061 DO - https://doi.org/10.1039/d4ra08683j VL - 15 IS - 5 SP - 3686 EP - 3692 PB - RSC AN - OPUS4-62506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Falkenhagen, Jana A1 - Weidner, Steffen ED - Barner-Kowollik, C. ED - Gründling, T. ED - Falkenhagen, Jana ED - Weidner, Steffen T1 - Hyphenated techniques N2 - Hyphenation of techniques has become a versatile tool in polymer analysis. It has been demonstrated that the complexity and heterogeneity of modern polymers and copolymers, in particular, could only be determined by a combination of several methods. With this regard, a chromatographic separation in various thermodynamic modes combined with mass spectral identification of polymer species provides new insights in polymer synthesis, modification, and degradation. Both methods are widely complementary and can therefore often compensate each other’s drawbacks. The development of suitable coupling interfaces, the introduction of AP devices, and an increasing application of ESI pushed polymer analysis toward new regions. Future developments in the field of MS detectors, lasers and software, as well new pressure-stable stationary chromatographic phases will aid in increasing the importance and acceptance of LC-MS coupling methods and will enable new applications in sophisticated polymer analysis. KW - MALDI KW - Chromatography KW - Coupling techniques PY - 2012 SN - 978-3-527-32924-3 SN - 978-3-527-64182-6 DO - https://doi.org/10.1002/9783527641826.ch7 SP - 209 EP - 235 PB - Wiley-VCH CY - Weinheim AN - OPUS4-26395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmid, C. A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Barner-Kowollik, C. T1 - In-depth LCCC-(GELC)-SEC characterization of ABA block copolymers generated by a mechanistic switch from RAFT to ROP N2 - A recently introduced procedure involving a mechanistic switch from reversible addition–fragmentation chain transfer (RAFT) polymerization to ring-opening polymerization (ROP) to form diblock copolymers is applied to synthesize ABA (star) block copolymers. The synthetic steps include the polymerization of styrene with R-group designed RAFT agents, the transformation of the thiocarbonyl thio end groups into OH functionalities, and their subsequent chain extension by ROP. The obtained linear ABA poly(ε-caprolactone)-block-poly(styrene)-block-poly(ε-caprolactone) (pCL-b-pS-b-pCL) (12 500 g mol¯¹ ≤ Mₙ ≤ 33 000 g mol¯¹) and the star-shaped poly(styrene)-block-poly(ε-caprolactone) (Mₙ = 36 000 g mol¯¹) copolymers were analyzed by size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The focus of the current study is on the detailed characterization of the ABA (star) block polymers via multidimensional chromatographic techniques specifically high performance liquid chromatography coupled to size exclusion chromatography (HPLC-SEC). In particular, we demonstrate the first time separation of poly(ε-caprolactone) (pCL) homopolymer and additionally poly(styrene) (pS) from the ABA poly(ε-caprolactone)-b-poly(styrene)-b-poly(ε-caprolactone) and star-shaped poly(styrene)-b-poly(ε-caprolactone) block copolymer utilizing critical conditions (CC) for pCL with concomitant gradient elution liquid chromatography (GELC). KW - Two-dimensional-liquid chromatography (2D-LC) KW - Liquid chromatography under critical conditions (LCCC) KW - Gradient elution liquid chromatography (GELC) KW - Soft ionization mass spectrometry (ESI, MALDI) KW - Reversible addition fragmentation chain transfer (RAFT) KW - Ring opening polymerization (ROP) PY - 2012 DO - https://doi.org/10.1021/ma2022452 SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 1 SP - 87 EP - 99 PB - American Chemical Society CY - Washington, DC AN - OPUS4-25464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen T1 - High molar mass cyclic poly(L-lactide)s by means of neat tin (II) 2-ethylhexanoate N2 - L-lactide was polymerized in bulk at 120, 140, 160 and 180°C with neat tin(II) 2-ethylhexanoate (SnOct2) as catalyst. At 180°C the Lac/Cat ratio was varied from 25/1 up to 8 000/1 and at 160°C from 25/1 up to 6 000/1. The vast majority of the resulting polylactides consist of cycles in combination with a small fraction of linear chains having one octanoate and one COOH end group. The linear chains almost vanished at high Lac/Cat ratios, as evidenced by MALDI-TOF mass spectrometry and measurements of intrinsic viscosities and dn/dc values. At Lac/Cat ratios <1000/1 the number average molar masses (Mn) are far higher than expected for stoichiometic initiation, and above 400/1 the molar masses vary relatively little with the Lac/Cat ratio. At 180° slight discoloration even at short times and degradation of the molar masses were observed, but at 160°C or below colorless products with weight average molar masses (Mw) up to 310 000 g mol-1 were obtained. The formation of high molar mass cyclic polylactides is explained by a ROPPOC (Ring-Opening Polymerizatiom with simultaneous Polycondensation) mechanism with intermediate formation of linear chains having one Sn-O-CH end group and one mixed anhydride end group. Additional experiments with tin(II)acetate as catalyst confirm this interpretation. These findings together with the detection of several transesterification mechanisms confirm previous critique of the Jacobson-Stockmayer theory. KW - Polylactide KW - MALDI-TOF MS KW - Cyclization PY - 2020 DO - https://doi.org/10.1039/d0py00811g VL - 11 IS - 32 SP - 5249 EP - 5260 PB - Royal Society for Chemistry AN - OPUS4-51130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grabicki, N. A1 - Nguyen, K. T. G. A1 - Weidner, Steffen A1 - Dumele, O. T1 - Confined Spaces in [n]Cyclo-2,7-pyrenylenes N2 - A set of strained aromatic macrocycles based on [n]cyclo2,7-(4,5,9,10-tetrahydro)pyrenylenes is presented with size dependent photophysical properties. The K-region of pyrene was functionalized with ethylene glycol groups to decorate the outer rim and thereby confine the space inside the macrocycle. This confined space is especially pronounced for n = 5, which leads to an internal binding of up to 8.0×104 M–1 between the ether-decorated [5]cyclo-2,7-pyrenylene and shape complementary crown ether–cation complexes. Both, the ether-decorated [n]cyclo-pyrenylenes as well as one of their host–guest complexes have been structurally characterized by single crystal X-ray analysis. In combination with computational methods the structural and thermodynamic reasons for the exceptionally strong binding have been elucidated. The presented rim confinement strategy makes cycloparaphenylenes an attractive supramolecular host family with a favorable, size-independent read-out signature and binding capabilities extending beyond fullerene guests. KW - Cycloparaphenylenes KW - Host–guest systems KW - Macrocycles KW - Molecular recognition KW - Supramolecular chemistry PY - 2021 DO - https://doi.org/10.1002/anie.202102809 SN - 1433-7851 VL - 60 IS - 27 SP - 1 EP - 7 PB - Wiley VCH AN - OPUS4-52517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Polymer characterisation by multidimensional techniques with focus on LC - MALDI/ESI-TOF-MS N2 - Since the first LC/ ESI-MS experiment of the Nobel prize winner John B. Fenn in 1984, the coupling of liquid chromatographic to mass spectrometric techniques gained a continuous rapid development. The lecture will give a general survey of different LC separation techniques as size exclusion chromatography (SEC), liquid adsorption chromatography (LAC), liquid chromatography at critical conditions (LCCC) and gradient elution liquid chromatography (GELC) combined with Matrix assisted Laser Desorption Ionization (MALDI) respectively Electrospray Ionization (ESI) Time of Flight (TOF) mass spectrometry. Often the deficiencies of stand-alone methods can be bridged. LC, blind to structural information needs mass spectrometry as one of the most powerful detectors able to give detailed information on e.g. the repeat units, functionalization or copolymer composition of the chromatographic separated constituents. A separation prior to MS reduces the polydispersity which is one of the reasons for failing of MS. Also problems with different ionization probabilities in complex mixtures can partly be overcame. On the basis of different examples on- and offline coupling principles will be compared and the pros and cons of both mass spectrometric techniques will be discussed. Recently, MALDI imaging techniques in coupling with chromatography have become interesting e.g. for visualization of copolymer composition. T2 - International Symposium GPC/SEC and Related Techniques CY - Amsterdam, The Netherlands DA - 26.09.2016 KW - Polymers KW - Liquid chromatography KW - MALDI-TOF-MS KW - ESI-TOF-MS PY - 2016 AN - OPUS4-37629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mahoney, C. M. A1 - Weidner, Steffen ED - Barner-Kowollik, C. ED - Gründling, T. ED - Falkenhagen, Jana ED - Weidner, Steffen T1 - Surface analysis and imaging techniques N2 - Over the past couple of decades, the field of imaging mass spectrometry has taken a quantum leap in the area of organic, polymeric, and biological analysis. SIMS, originally developed for characterization of inorganic materials and semiconductors, is now used on a regular basis for the surface and in-depth characterization of polymers and other soft samples. The recent development of cluster sources over the past 15 years has resulted in a major paradigm shift in SIMS, moving from 2-D to 3-D analysis in polymeric materials. MALDIs recent development of imaging methodology has made an overwhelming impact in the biological community. The ability to detect high-mass proteins and other organic compounds remains unrivaled. Furthermore, some of these instruments can now be operated under ambient pressure conditions, thus making it a much more versatile tool. Although this is a time of expansion in the entire field of surface mass spectrometry, DESI and PDI methods are right at the beginning of their growth curve. It is expected, therefore, that significant developments will be observed in the coming years as these techniques mature. It has been said that these methods represent the future of desorption mass spectrometry. This is very likely to be true. KW - Surface analysis KW - Imaging techniques PY - 2012 SN - 978-3-527-32924-3 SN - 978-3-527-64182-6 DO - https://doi.org/10.1002/9783527641826.ch6 SP - 149 EP - 207 PB - Wiley-VCH CY - Weinheim AN - OPUS4-26396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lauer, Franziska A1 - Seifert, Stephan A1 - Kneipp, Janina A1 - Weidner, Steffen T1 - Simplifying the preparation of pollen grains for MALDI-TOF MS classification N2 - Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) is a well-implemented analytical technique for the investigation of complex biological samples. In MS, the sample preparation strategy is decisive for the success of the measurements. Here, sample preparation processes and target materials for the investigation of different pollen grains are compared. A reduced and optimized sample preparation process prior to MALDI-TOF measurement is presented using conductive carbon tape as target. The application of conductive tape yields in enhanced absolute signal intensities and mass spectral pattern information, which leads to a clear separation in subsequent pattern analysis. The results will be used to improve the taxonomic differentiation and identification, and might be useful for the development of a simple routine method to identify pollen based on mass spectrometry. KW - MALDI KW - Conductive carbon tape KW - Pollen KW - Sample pretreatment KW - Principal component analysis PY - 2017 DO - https://doi.org/10.3390/ijms18030543 SN - 1422-0067 SN - 1661-6596 VL - 18 IS - 3 SP - 543-1 EP - 543-11 PB - MDPI AN - OPUS4-41733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lahcini, M. A1 - Weidner, Steffen A1 - Oumayama, J. A1 - Scheliga, F. A1 - Kricheldorf, H. R. T1 - Unsaturated Copolyesters of Lactide N2 - Four classes of unsaturated copolyesters of L-lactide were prepared either from isosorbide or bis(hydroxymethyl)tricyclodecane in combination with fumaric acid or from 1,4-butenediol or 1,4- butynediol with terephthalic acid. All syntheses were performed in such a way that lactide was oligomerized with a diol as the initiator and the resulting oligomers were polycondensed with a dicarboxylic acid dichloride either in a one-pot synthesis or in a two-step procedure. For most copolyesters the SEC measurements gave weight average molecular weights in the range of 30–60 kg mol⁻1 and dispersities in the range of 4.2–6.2. The MALDI-TOF mass spectra displayed a high content of cycles and indicated an irreversible kinetic course of all polycondensations. Glass-transition temperatures (Tg) above 90 °C were only found for two copolyesters of isosorbide. Addition of bromine to copolyesters of 1,4-butenediol yielded flame retarding biodegradable polymers. KW - Copolyester KW - MALDI-TOF MS KW - SEC KW - Lactide PY - 2016 DO - https://doi.org/10.1039/c6ra16008e VL - 2016/6 IS - 96 SP - 93496 EP - 93504 PB - Royal Society of Chemistry AN - OPUS4-37913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Differences in MALDI Ionization of neat linear and cyclic poly(L-lactide)s N2 - In addition to molar mass distribution (MMD) synthetic polymers often exhibit an additional chemical heterogeneity distribution, expressed by different end groups and other structural variations (e.g. tacticity, copolymer composition etc.). Ionization in MALDI MS is always strongly affected by such chemical properties. For example, the abundance of cyclics in MALDI TOF mass spectra is frequently reported to greatly exceed that of linears. Thus, the MALDI ionization behavior of various neat end-capped linear poly(L-lactide)s and one cyclic poly(L-lactide) was investigated and compared with that of blends of both structures. Moreover, the influence of the cationizing salt was investigated too. Neat compounds and various blends of cyclic and linear species were prepared and studied using two MALDI TOF mass spectrometers under identical conditions with regard to sample preparation and instrumental conditions, except for the laser power and the salt used for cationization. Polymer samples were additionally characterized by NMR and SEC. The steady increase of the laser intensity caused an exponential increase of the peak intensities of both linear and cyclic polylactides.The response of linear polylactides (in the investigated molecular mass range), whether as neat polymer or in blends with other linear polylactides was almost similar. This clearly supports our assumption that ionization in MALDI is probably unaffected by the end group structure.The variation of the laser power shows only little effect on the intensity ratio of linear-to linear and cyclic-to-linear polylactides in blends. Whereas neat linear polylactides at all laser intensities have a significantly higher abundance than neat cyclics, in mixtures of both an overestimation of cyclic species in MALDI TOF mass spectra of polylactides was found. However, this is far less distinct than frequently reported for other polymers.Concluding, peak suppression of linear polymers in mixtures of both architectures can be excluded, which also means, that polylactides showing only peaks of cyclic compounds in their MALDI - TOF mass spectra do not contain a significant fraction of linear analogues. Our study is the first systematic comparison of the MALDI ionization of neat and blended cyclic and linear polylactides. T2 - ASMS 2020 Reboot CY - Online meeting DA - 01.06.2020 KW - MALDI KW - Ionization KW - Linear KW - Cyclic KW - Polylactide PY - 2020 AN - OPUS4-50852 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI Mass spectrometry of synthetic polymers – making molecular elephants to fly N2 - The importance of MALDI TOF mass spectrometry for the analysis of synthetic polymers is shown and some specific issues influencing the analysis e.g. polymer mass dispersity, matrix and matrix homogeneity, nature of cations and end groups, sequence distribution are discussed by means of examples. T2 - Merck Polymer Seminar CY - Online meeting DA - 29.04.2021 KW - MALDI-ToF MS KW - Ionization KW - Desorption KW - Polymers PY - 2021 AN - OPUS4-52545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao 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 - JOUR A1 - Trimpin, S. A1 - Lee, C. A1 - Weidner, Steffen A1 - El-Baba, T. A1 - Lutomski, C. A1 - Inutan, E. A1 - Foley, C. A1 - Ni, C.-K. A1 - McEwen, C. T1 - Unprecedented Ionization Processes in Mass SpectrometryProvide Missing Link between ESI and MALDI N2 - In the field of mass spectrometry,producing intact, highly-charged protein ions from surfaces is a conundrum with significant potential payoff in application areas ranging from bio-medical to clinical research. Here, we report on the ability to form intact, highly-charged protein ions on high vacuum time-of-flight mass spectrometers in the linear and reflectron modes achievable using experimental conditions that allow effective matrix removal from both the sample surfaces and from the charged clusters formed by the laser Ablation event. The charge states are the highest reported on high vacuum mass spectrometers, yet they remain at only around athird of the highest charge obtained using laser ablation with a suitable matrix at atmospheric pressure. Other than physical instrument modifications, the key to forming abundant and stable highly-charged ions appears to be the volatility of the matrix used. Cumulative results suggest mechanistic links between the ionization process reported here and traditional ionization methods of electrospray ionization and matrix-assisted laser desorp-tion/ionization. KW - MALDI KW - Electrospray KW - Mass spectrometry KW - Ionization PY - 2018 DO - https://doi.org/10.1002/cphc.201701246 SN - 1439-4235 SN - 1439-7641 VL - 19 IS - 5 SP - 581 EP - 589 PB - Wiley-VCH AN - OPUS4-44404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lee, C. A1 - Inutan, E. D. A1 - Chen, J. L. A1 - Mukeku, M. M. A1 - Weidner, Steffen A1 - Trimpin, S. A1 - Ni, C.-K. T1 - Toward understanding the ionization mechanism of matrix‐assisted ionization using mass spectrometry experiment and theory N2 - Matrix‐assisted ionization (MAI) mass spectrometry does not require voltages, a laser beam, or added heat to initiate ionization, but it is strongly dependent on the choice of matrix and the vacuum conditions. High charge state distributions of nonvolatile analyte ions produced by MAI suggest that the ionization mechanism may be similar to that of electrospray ionization (ESI), but different from matrix‐assisted laser desorption/ionization (MALDI). While significant information is available for MAI using mass spectrometers operating at atmospheric and intermediate pressure, little is known about the mechanism at high vacuum. Eleven MAI matrices were studied on a high‐vacuum time‐of‐flight (TOF) mass spectrometer using a 266 nm pulsed laser beam under otherwise typical MALDI conditions. Detailed comparisons with the commonly used MALDI matrices and theoretical prediction were made for 3‐nitrobenzonitrile (3‐NBN), which is the only MAI matrix that works well in high vacuum when irradiated with a laser. Screening of MAI matrices with good absorption at 266 nm but with various degrees of volatility and laser energies suggests that volatility and absorption at the laser wavelength may be necessary, but not sufficient, criteria to explain the formation of multiply charged analyte ions. 3‐NBN produces intact, highly charged ions of nonvolatile analytes in high‐vacuum TOF with the use of a laser, demonstrating that ESI‐like ions can be produced in high vacuum. Theoretical calculations and mass spectra suggest that thermally induced proton transfer, which is the major ionization mechanism in MALDI, is not important with the 3‐NBN matrix at 266 nm laser wavelength. 3‐NBN:analyte crystal morphology is, however, important in ion generation in high vacuum. The 3‐NBN MAI matrix produces intact, highly charged ions of nonvolatile compounds in high‐vacuum TOF mass spectrometers with the aid of ablation and/or heating by laser irradiation, and shows a different ionization mechanism from that of typical MALDI matrices. KW - Ionization KW - MALDI-TOF MS KW - Mechanism PY - 2021 DO - https://doi.org/10.1002/rcm.8382 VL - 35 IS - 51 SP - e8382 PB - John Wiley & Sons AN - OPUS4-49209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Coupling of chromatographic and spectrometric techniques for polymer characterization N2 - Presentation of coupling of polymer chromatography and polymer mass spectrometry based on different examples. T2 - Kolloquium CY - Universität für Bodenkultur, Wien, Austria DA - 14.06.2019 KW - LCCC KW - Mass spectrometry of polymers KW - LC x MALDI/ESI-TOF-MS KW - Liquid chromatography of polymers PY - 2019 AN - OPUS4-48223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, A. A1 - Falkenhagen, Jana A1 - Kricheldorf, H. R. T1 - SnOct2-catalyzed and alcohol-initiated ROPs of L-lactide – About the influence of initiators on chemical reactions in the melt and the solid state N2 - SnOct2 (Sn(II) 2-ethylhexanoate) catalyzed ROPs of L-lactide were performed in bulk with eight different alcohols as initiators. The time was varied between 1 h and 24 h for all initiators. For two initiators the temperature was also lowered to 115 ◦C. Even-numbered chains were predominantly formed in all polymerizations at short times, but the rate of transesterification (e.g. even/odd equilibration) and the molecular weight distribution were found to depend significantly on the nature of the initiator. Observed transesterification reactions also continued in solid poly (L-lactide), and with the most active initiator, almost total equilibration was achieved even at 130 ◦C. This means that all chains including those of the crystallites were involved in transesterification reactions proceeding across the flat surfaces of the crystallites. The more or less equilibrated crystalline polylactides were characterized by DSC and SAXS measurements with regard to their melting temperature (Tm), crystallinity and crystal thickness. KW - Polylactide KW - MALDI-TOF MS KW - Crystallization KW - Catalysts KW - SAXS PY - 2021 DO - https://doi.org/10.1016/j.eurpolymj.2021.110508 VL - 153 SP - 110508 PB - Elsevier Ltd. AN - OPUS4-52633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baumann, Maria A1 - Falkenhagen, Jana A1 - Weidner, Steffen A1 - Wold, C. A1 - Uliyanchenko, E. T1 - Characterization of copolymers of polycarbonate and polydimethylsiloxane by 2D chromatographic separation, MALDI-TOF mass spectrometry, and FTIR spectroscopy N2 - The structure and composition of polycarbonate polydimethylsiloxane copolymer (PC-co-PDMS) was investigated by applying various analytical approaches including chromatographic separation methods, spectrometric, and spectroscopic detection techniques. In particular, size exclusion chromatography (SEC) and liquid adsorption chromatography operating at different conditions (e.g. using gradient solvent systems) were used to achieve separations according to molar mass and functionality distribution. The coupling of both techniques resulted in fingerprint two-dimensional plots, which could be used to easily compare different copolymer batches. Matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry was applied for structural investigations. The different ionization behavior of both comonomers, however, strongly limited the applicability of this technique. In contrast to that, Fourier-transform Infrared (FTIR) spectroscopy could be used to quantify the amount of PDMS in the copolymer at different points in the chromatogram. The resulting methodology was capable of distinguishing PC-co-PDMS copolymer from PC homopolymer chains present in the material. KW - FTIR KW - Liquid chromatography KW - Mass spectrometry KW - Gradient elution KW - Polycarbonate-co-dimethylsiloxane copolymer PY - 2020 DO - https://doi.org/10.1080/1023666X.2020.1820170 VL - 25 IS - 7 SP - 1 EP - 12 PB - Taylor & Francis AN - OPUS4-51369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Coupling of chromatographic and spectrometric techniques for polymer characterization N2 - Coupling of chromatographic and spectrometric techniques for polymer characterization; focus topics: LCxMALDI-TOF-MS and UPLC x ESI-TOF-MS T2 - 16. Tagung des Arbeitskreises Polymeranalytik CY - Online meeting DA - 22.03.2022 KW - Liquid chromatography KW - Mass spectrometry KW - Polymers KW - Two-dimensional chromatography (2D-LC) PY - 2022 AN - OPUS4-54567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Polymer mass spectrometry at BAM with special emphasis on MALDI and ESI N2 - Since its introduction mass spectrometric techniques like Matrix-assisted Laser Desorption/ionization (MALDI) and Electrospray Ionization (ESI) have become indispensable for synthetic polymer analyses. Ideally, various polymer properties (monomer structure, masses, mass distribution, end groups) can be determined simultaneously. However, in real life these experiments are always affected by important structural parameters and instrumental limitations. A short introduction focussing on latest findings with respect to ionisation principles and mechanisms will be given. Recent results from our group will be presented and efforts to avoid common drawbacks of polymer mass spectrometry will be discussed. In this regard, MALDI - Imaging mass spectrometry and the 2D hyphenation of MS with different chromatographic separation techniques were especially useful, since they can provide additional information and reduce the complexity of polymer analyses. T2 - 21. European Symposium on Polymer Spectroscopy CY - Linz, Austria DA - 13.01.2020 KW - Mass spectrometry KW - MALDI-TOF MS KW - ESI-TOF MS KW - Polymer PY - 2020 AN - OPUS4-50260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Separation of polysterene nanoparticles with different coatings using 2D off-line coupling of asymmetrical flow field flow fractionation and capillary electrophoresis N2 - The successful off-line coupling of asymmetrical flow field flow fractionation (AF4) and capillary electrophoresis (CE) for Separation of nanoparticles (NPs) with different surface coatings was shown. Two mixtures of polystyrene nanoparticles (PS-NPs) with comparable core sizes (20 nm and 50 nm) but different coatings (no coating/carboxyl-coated) were studied. Separation in either method resulted in non-baseline resolved or non-separated peaks. In contrast, two-dimensional off-line coupling of AF4 and CE resulted in clearly separated regions in their 2 D plots and can obviouly improve separation resolution. T2 - FFF 2020 CY - Wien, Austria DA - 23.02.2020 KW - Capillary electrophoresis KW - Nanoparticle PY - 2020 AN - OPUS4-50487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Panne, Ulrich A1 - Falkenhagen, Jana T1 - Power of ultra performance liquid chromatography/electrospray ionization-MS reconstructed ion chromatograms in the characterization of small differences in polymer microstructure N2 - From simple homopolymers to functionalized, 3-dimensional structured copolymers, the complexity of polymeric materials has become more and more sophisticated. With new applications for instance in the semiconductor or pharmaceutical industry, the requirements for the characterization have risen with the complexity of the used polymers. For each additional distribution, an additional dimension in analysis is needed. Small, often isomeric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector, but affect the properties of materials significantly. For a drug delivery system for example, the degree of branching and branching distribution is crucial for the formation of micelles. Instead of a complicated, time consuming and/or expensive 2d-chromatography or ion mobility spectrometry (IMS) method, that also has its limitations, in this work a simple approach using size exclusion chromatography (SEC) coupled with electrospray ionization mass spectrometry (ESI) is proposed. The online coupling allows the analysis of reconstructed ion chromatograms (RIC) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities. Although some microstructural heterogeneities like short chain branching can for large polymers be characterized with methods such as light scattering, for oligomers where the heterogeneities just start to form and their influence is at the maximum, they are inaccessible with these methods. It is also shown, that with a proper calibration even quantitative information can be obtained. This method is suitable to detect small differences in e. g. branching, 3d-structure, monomer sequence or tacticity and could potentially be used in routine analysis to quickly determine deviations. KW - Polymer KW - Microstructure KW - UPLC KW - ESI-TOF-MS KW - Reconstructed ion chromatograms PY - 2018 DO - https://doi.org/10.1021/acs.analchem.7b05214 SN - 0003-2700 SN - 1520-6882 VL - 90 IS - 5 SP - 3467 EP - 3474 PB - ACS Publ. CY - Washington, DC AN - OPUS4-44423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholz, Philipp A1 - Ulbricht, Alexander A1 - Joshi, Y. A1 - Gollwitzer, Christian A1 - Weidner, Steffen T1 - Microstructure of polymer-imprinted metal–organic frameworks determined by absorption edge tomography N2 - Mechanochemically synthesized metal–organic Framework material HKUST-1 in combination with acrylonitrile butadiene styrene polymer was used to form a polymer metal–organic framework composite material by a simple extruder. This composite filament was used for 3D printing. Xray diffraction measurements were used to prove the homogeneous distribution of the metal–organic framework in the polymer on a centimeter scale, whereas X-ray Absorption Edge Tomography using a synchrotron radiation source was able to evaluate the 3D distribution of the metal–organic framework material both in the filament and the resultant printed sample with a resolution of a few lm. Our very first data indicate that, apart from a few clusters having significantly higher Cu concentration, HKUST-1 is distributed homogeneously down to the 100 lm length scale in both polymer bulk materials in the form of clusters with a size of a few lm. Absorption Edge Tomography in combination with data fusion also allows for the calculation of the metal–organic framework amount located on the external polymer surface. KW - MOF KW - Polymer KW - AET PY - 2019 DO - https://doi.org/10.3139/146.111817 SN - 1862-5282 SP - 1 EP - 10 PB - Carl Hanser Verlag AN - OPUS4-49483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Weidner, Steffen ED - Matyjaszewski, K. ED - Möller, M. T1 - Mass spectrometry: MALDI (Matrix-Assisted Laser Desorption/Ionization) and ESI (Electrospray Ionization) N2 - In recent years mass spectrometric methods, in particular matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) time-of-flight (TOF) mass spectrometry (MS) have become indispensable tools for analyzing molecular masses and mass distributions of polymers. Moreover, these techniques offer the advantage of being able to determine simultaneously chemical functionality, and compositional and topological distributions of polymers. Especially in combination with liquid and/or gas phase separation methods, a comprehensive polymer characterization can be achieved and the difficulties of MS to analyze chemically heterogeneous polymers, copolymers, and samples with broad molecular mass distribution can be overcome. KW - MALDI KW - ESI KW - Polymer KW - Electrospray ionization KW - Mass spectrometry KW - Matrix-assisted laser desorption/ionization KW - Tandem MS KW - Time of flight PY - 2012 SN - 978-0-444-53349-4 DO - https://doi.org/10.1016/B978-0-444-53349-4.00023-6 VL - 2 SP - 93 EP - 109 PB - Elsevier CY - Amsterdam AN - OPUS4-26098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Soulis, S. A1 - Triantou, D. A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Simitzis, J. T1 - Structural analysis of biodegradable low-molecular mass copolyesters based on glycolic acid, adipic acid and 1,4 butanediol and correlation with their hydrolytic degradation N2 - Copolyesters of glycolic acid combined with adipic acid and 1,4 butanediol were synthesized, their in vitro hydrolytic degradation was studied and correlated with their structure. The hydrolytic degradation of the copolyesters was directly related with the degree of crystallinity and the diameter of the crystallites. It was found that glycolate units disturb the ordering of the butylene adipate units, which results in a decrease of the crystallinity. By comparing the hydrolysis parameters of synthesized copolyesters with those of similar aliphatic copolyesters a hydrolysis mechanism was proposed. According to this mechanism, the degradation takes place not only by the loss of end units, but also through the removal of larger segments. MALDI-TOF MS data showed that the possibility of a copolyester macromolecule forming cyclic structures correlates with the arrangement of ester groups in the macromolecules and the structure of the linear segments. KW - Biodegradable KW - Biopolymers KW - Hydrolytic degradation KW - Ft-IR KW - Matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry KW - MALDI-TOF-MS PY - 2012 DO - https://doi.org/10.1016/j.polymdegradstab.2012.09.002 SN - 0141-3910 SN - 1873-2321 VL - 97 IS - 11 SP - 2091 EP - 2103 PB - Applied Science Publ. CY - London AN - OPUS4-26723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen A1 - Scheliga, F. T1 - Poly(Epsilon-caprolactone) by combined ring-opening polymerization and azeotropic polycondensation - The role of cyclization and equilibration N2 - Using three different catalysts, water-initiated polymerizations of ε-caprolactone were conducted in bulk with variation of the monomer/water ratio. The resulting CH2OH and CO2H- terminated polylactones were subjected in situ to azeotropic polycondensations. With Bi-triflate and temperatures, the polycondensations were not much successful and involved side reactions. With ZnCl2, and especially SnCl2, considerably higher molar masses were achieved. The substitution of toluene for chlorobenzene for refluxing gave better results. The polycondensations broadened the molar mass distribution of the ROP-based prepolymers, and polydispersities between 1.4-1.8 were obtained. The MALDI-TOF mass spectra revealed that the polycondensations significantly enhanced the fraction of rings due to efficient 'end-biting' reactions. By comparison with copolymerization experiments and Sn methoxide-initiated polymerizations, it was demonstrated that equilibration reactions, such as the formation of rings by 'back-biting,' did not occur. KW - Ring-opening polymerization KW - Epsilon-caprolactone (e-CL) KW - Cyclization KW - MALDI-TOF mass spectrometry KW - Polycondensation KW - Polyesters PY - 2012 DO - https://doi.org/10.1002/pola.26222 SN - 0360-6376 SN - 0887-624X VL - 50 IS - 20 SP - 4206 EP - 4214 PB - Wiley CY - Hoboken, NJ AN - OPUS4-26500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Falkenhagen, Jana A1 - Breßler, Ingo T1 - Copolymer composition determined by LC-MALDI-TOF MS coupling and 'MassChrom2D' data analysis N2 - The MALDI-TOF MS analysis of copolymers very often results in complex spectra. A chromatographic separation/fractionation prior to the MALDI investigation can be advantageous since the MALDI mass spectra of fractions very often reveal well-resolved peaks of distinguishable copolymer series. For this purpose, different modes of chromatography have been applied. Chromatographic runs were transferred to MALDI targets utilizing a combined air/electrospray deposition device. Using the new MassChrom2D software, fraction-dependent 2D copolymer compositions plots were obtained providing additional information on the chromatographic mode, and enabling fast modification of conditions to increase separation. KW - Copolymer composition KW - Chromatography KW - Coupling KW - MALDI-TOF mass spectrometry PY - 2012 DO - https://doi.org/10.1002/macp.201200169 SN - 1022-1352 SN - 1521-3935 VL - 213 IS - 22 SP - 2404 EP - 2411 PB - Wiley-VCH CY - Weinheim AN - OPUS4-27270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kricheldorf, H. R. T1 - Cyclization and dispersity of polyesters N2 - Starting out from Flory`s most probable Distribution concept, correct and incorrect evaluations of SEC measurements are discussed. Using the correct mode, polyesters prepared by irreversible and reversible polycondensation methods were studied. Polyesters of α,ω−alkanediols and isophthalic acid or polyesters of diphenols and sebacic acid were prepared by three different irreversible polyconcensation methods. Formation of cyclic oligo and polyesters was monitored by MALDI-TOF mass spectrometry and dispersities were measured by SEC. The results are compared with the theories of Flory and Odian. Eqilibrated polyesters were prepared by reversible polycondensation of ethyl 6-hydroxycaproate or by alcohol-initiated ring-opening polymerization of ε-caprolactone. Various catalysts were compared. The influence of dilution and of di- or multifunctional initiators was evaluated. Furthermore, equilibrated polylactides were prepared from L- or meso-lactide at 120, 160 and 180°C. A fast even-odd equilibration was discovered in addition to reversible cyclization and intermolecular transesterification. The influence of these different equilibration mechanisms on the dispersity was investigated. The preparative and theoretical consequences are discussed. T2 - Polycondensation 2016 CY - Moscow, Russia DA - 11.09.2016 KW - Polyester KW - Cyclization KW - MALDI-TOF MS KW - SEC PY - 2016 AN - OPUS4-38365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - You, Zengchao A1 - Meier, Florian A1 - Weidner, Steffen ED - Weidner, Steffen T1 - Comparison of miniaturized and conventional asymmetrical flow field flow fractionation (AF4) channels for nanoparticle separation 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. KW - Nanoparticles separation asymetrical flow field flow fractionation PY - 2017 DO - https://doi.org/10.3390/separations4010008 SN - 2297-8739 VL - 4 IS - 1 SP - 8, 1 EP - 11 AN - OPUS4-47196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Holger A1 - Baldofski, Stefanie A1 - Hoffmann, Kristin A1 - Flemig, Sabine A1 - Silva, C. P. A1 - Esteves, V. I. A1 - Emmerling, Franziska A1 - Panne, Ulrich A1 - Schneider, Rudolf T1 - Structural considerations on the selectivity of an immunoassay for sulfamethoxazole N2 - Sulfamethoxazol (SMX),a sulfonamide, is a widely used bacteriostatic antibiotic and therefore a promising marker for the entry of anthropogenic Pollution in the environment. SMX is frequently found in wastewater and surface water. This study presents the production of high affinity and selective polyclonal antibodies for SMX and the development and Evaluation of a direct competitive enzyme-linked immunosorbent assay(ELISA)for the quantification of SMX in environmental watersamples. The crystal structures of the cross-reacting compounds sulfamethizole, N4-acetyl-SMX andsuccinimidyl-SMX were determined by x-ray diffraction aiming to explain their high cross-reactivity. These crystal structures are described for the first time. The quantification range of the ELISA is 0.82–63 µg/L. To verify our results, the SMX concentration in 20 environmental samples,including wastewater and surfacewater,was determined by ELISA and tandem mass spectrometry(MS/MS).A good Agreement of the measured SMX concentrations was found with average recoveries of 97–113%for the results of ELISA compared to LC-MS/MS. KW - X-Ray diffraction KW - ELISA KW - LC-MS/MS KW - Sulfamethoxazole PY - 2016 DO - https://doi.org/10.1016/j.talanta.2016.05.049 SN - 0039-9140 SN - 1873-3573 IS - 158 SP - 198 EP - 207 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-38530 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Somasundaram, S. K. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Krishnan, S. A1 - Senthilkumar, K. A1 - Joseyphus, R.J. T1 - New insights into pertinent Fe-complexes for the synthesis of iron via the instant polyol process N2 - Chemically synthesized iron is in demand for biomedical applications due to its large saturation magnetization compared to iron oxides. The polyol process, suitable for obtaining Co and Ni particles and their alloys, is laborious in synthesizing Fe. The reaction yields iron oxides, and the reaction pathway remains unexplored. This study shows that a vicinal polyol, such as 1,2-propanediol, is suitable for obtaining Fe rather than 1,3-propanediol owing to the formation of a reducible Fe intermediate complex. X-ray absorption spectroscopy analysis reveals the ferric octahedral geometry and tetrahedral geometry in the ferrous state of the reaction intermediates in 1,2-propanediol and 1,3-propanediol, respectively. The final product obtained using a vicinal polyol is Fe with a γ-Fe2O3 shell, while the terminal polyol is favourable for Fe3O4. The distinct Fe–Fe and Fe–O bond lengths suggest the presence of a carboxylate group and a terminal alkoxide ligand in the intermediate of 1,2-propanediol. A large Fe–Fe bond distance suggests diiron complexes with bidentate carboxylate bridges. Prominent high-spin and low-spin states indicate the possibility of transition, which favors the reduction of iron ions in the reaction using 1,2-propanediol. KW - XAS KW - Nanoparticle PY - 2023 DO - https://doi.org/10.1039/D3CP01969A SN - 1463-9076 VL - 25 IS - 33 SP - 21970 EP - 21980 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Terkawi, Abdal-Azim A1 - Scholz, G. A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - Hydrated and dehydrated Ca-coordination polymers based on benzene-dicarboxylates: mechanochemical synthesis, structure refinement, and spectroscopic characterization N2 - A series of Ca-based coordination polymers were prepared mechanochemically by milling Ca(OH)2 with phthalic acid (H2oBDC), isophthalic acid (H2mBDC), and terephthalic acid (H2pBDC). The hydrated compounds [Ca(oBDC)(H2O)], [Ca(mBDC)(H2O)3.4], and [Ca(pBDC)(H2O)3] were prepared for the first time via mechanochemical routes. The refined structures were validated by extended X-ray absorption data. The new dehydrated compound [Ca(oBDC)] (1-H2O), obtained after the thermal post-treatment of 1 in a reversible phase transition process, was determined ab initio based on the powder X-ray diffraction (PXRD) data. The materials were thoroughly characterized using elemental analysis, thermal analysis, and spectroscopic methods: magic-angle spinning NMR and attenuated total reflection-infrared spectroscopy. The specific surface areas and sorption properties of the hydrated and dehydrated samples were determined using the isotherms of gas sorption and dynamic vapor sorption measurements. KW - Mechanochemistry KW - XRD PY - 2018 UR - http://pubs.rsc.org/en/content/articlehtml/2017/ce/c7ce01906h DO - https://doi.org/10.1039/C7CE01906H VL - 20 SP - 946 EP - 961 PB - Royal Society of Chemistry AN - OPUS4-44440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Surov, A. A1 - Vasilev, N. A1 - Voronin, A. A1 - Churakov, A. A1 - Emmerling, Franziska A1 - Perlovich, G. T1 - Ciprofloxacin salts with benzoic acid derivatives: structural aspects, solid-state properties and solubility performance N2 - n this work, three new pharmaceutical hydrated salts of ciprofloxacin with selected derivatives of benzoic acid, namely 4-hydroxybenzoic acid, 4-aminobenzoic acid and gallic acid, were obtained and systematically investigated by several solid-state analytical techniques. In situ Raman spectroscopy was applied to elucidate the alternative pathways of the solid forms' formation under mechanochemical conditions. Crystal structure analysis and a CSD survey allowed us to establish a distinct supramolecular motif formed by infinite columnar stacks of ciprofloxacin dimers arranged in the “head-to-tail” manner. An alternative “head-to-head” packing arrangement was only observed in the crystal of the hydrated ciprofloxacin salt with 4-aminobenzoic acid. In addition, the pH-solubility behavior of the solid forms was thoroughly investigated. Furthermore, a distinct structure–property relationship between the specific features of the supramolecular organization of the hydrated salts and their solubility was observed and discussed. KW - Mechanochemistry KW - XRD PY - 2020 DO - https://doi.org/10.1039/D0CE00514B VL - 22 IS - 25 SP - 4238 EP - 4249 AN - OPUS4-51818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobina, E. A1 - Zimathies, Annett A1 - Prinz, Carsten A1 - Emmerling, Franziska A1 - de Santis Neves, R. A1 - Wang, H. A1 - Mizuno, K. A1 - Devoille, L. A1 - Steel, E. A1 - Ceyhan, A. A1 - Sadak, E. ED - Sobina, E. T1 - Final report of CCQM-K153 Measurement of Specific Adsorption A [mol/kg] of N-2 and Kr on nonporous SiO2 at LN temperature (to enable a traceable determination of the Specific Surface Area (BET) following ISO 9277) N2 - CCQM key comparison K-153 Measurement of Specific Adsorption A [mol/kg] of N-2 and Kr on nonporous SiO2 at LN temperature (to enable a traceable determination of the Specific Surface Area (BET) following ISO 9277) has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of specific adsorption, BET specific surface area) of nonporous substances (sorbents, ceramics, catalytic agents, etc) used in advanced technology. In this key comparison, a commercial nonporous silicon dioxide was supplied as a sample. Eight NMIs participated in this key comparison, but only five NMI's have reported in time. All participants used a gas adsorption method, here nitrogen and (or) krypton adsorption at 77.3 K, for analysis according to the international standards ISO 15901-2 and 9277. In this key comparison, the degrees of equivalence uncertainties for specific adsorption nitrogen and krypton, BET specific surface area were established. KW - Nonporous SiO2 KW - Specific Adsorption of N-2 and Kr KW - BET specific surface area PY - 2019 DO - https://doi.org/10.1088/0026-1394/56/1A/08013 VL - 56 IS - 1A SP - 08013 PB - IOP publishing Ltd CY - Bristol, UK AN - OPUS4-50358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Haferkamp, Sebastian A1 - Kraus, Werner T1 - Studies on the mechanochemical Knoevenagel condensation of fluorinated benzaldehyde derivates N2 - The mechanochemical Knoevenagel condensation of three fluorinated benzaldehyde derivates and malononitrile was investigated. The reactions were performed under solvent- and catalyst-free conditions and resulted in highly crystalline products after crystallization from a viscous phase in the milling jar. The quality of the obtained crystals was sufficient for single-crystal X-ray diffraction circumventing a recrystallization step. To gain more information on the reaction, progress was investigated in situ using time-resolved Raman spectroscopy. The results show a direct conversion of the reactants. KW - C-C coupling KW - Knoevenagel condensation KW - In situ KW - Mechanochemistry PY - 2018 DO - https://doi.org/10.1007/s10853-018-2492-0 SN - 0022-2461 VL - 53 IS - 19 SP - 13713 EP - 13718 PB - Springer Link AN - OPUS4-45682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Emmerling, Franziska T1 - Revealing Mechanical Plastic Bending in Coordination Polymer Crystals N2 - Crystalline molecular materials with mechanical flexibility are promising for technological development. This is particularly true for the development of advanced materials with optoelectronic and biomedical applications. While a growing number of mechanically flexible crystalline molecular materials are being reported,1 they remain scarce. At present, most discoveries are serendipitous, as limited design strategies are currently known. Amongst these strategies Desiraju et. al. suggested that elastic materials must contain herringbone structures.2 For plastic crystals, the so-called ‘shape-synthon’ strategy has been developed, in which weak non-covalent interactions are introduced into structures to facilitate mobility of molecules.3 This includes formation of slip planes. Generally, these models have performed very well at predicting and rationalizing the mechanical properties of new materials. Recently, however, a family of one-dimensional covalent networks (coordination polymers; CPs) has been described, which show mechanical elasticity. With drastically different structural chemistry, these systems do not seem to adhere to the currently established rules. Herein, we present the first such system: a plastically bendable crystal of a 1D CP, [Zn(-Cl)2(3,5-Cl2Py)2]n (where 3,5-Cl2Py = 3,5-dichloro pyridine). This CP crystallizes in a tetragonal, and can therefore be bent over two major faces to acute angles without fracturing. We conducted bending and indentation experiments to quantify the mechanical properties of the CP crystal. This was complimented by Vibrational (Raman and Terahertz) spectroscopy and theoretical calculations for deeper understanding of molecular level structural deformation. T2 - 32nd European Crystallographic Meeting (ECM32) CY - University of Vienna, Vienna, Austria DA - 18.08.2019 KW - Mechanical Flexiblity KW - Crystal engineering KW - Coordination Polymers PY - 2019 AN - OPUS4-49875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pütz, E. A1 - Smales, Glen Jacob A1 - Jegel, O. A1 - Emmerling, Franziska A1 - Tremel, W. T1 - Tuning ceria catalysts in aqueous media at the nanoscale: how do surface charge and surface defects determine peroxidase- and haloperoxidase-like reactivity N2 - Designing the shape and size of catalyst particles, and their interfacial charge, at the nanometer scale can radically change their performance. We demonstrate this with ceria nanoparticles. In aqueous media, nanoceria is a functional mimic of haloperoxidases, a group of enzymes that oxidize organic substrates, or of peroxidases that can degrade reactive oxygen species (ROS) such as H2O2 by oxidizing an organic substrate. We show that the chemical activity of CeO2−x nanoparticles in haloperoxidase- and peroxidaselike reactions scales with their active surface area, their surface charge, given by the ζ-potential, and their surface defects (via the Ce3+/Ce4+ ratio). Haloperoxidase-like reactions are controlled through the ζ-potential as they involve the adsorption of charged halide anions to the CeO2 surface, whereas peroxidase-like reactions without charged substrates are controlled through the specific surface area SBET. Mesoporous CeO2−x particles, with large surface areas, were prepared via template-free hydrothermal reactions and characterized by small-angle X-ray scattering. Surface area, ζ-potential and the Ce3+/Ce4+ ratio are controlled in a simple and predictable manner by the synthesis time of the hydrothermal reaction as demonstrated by X-ray photoelectron spectroscopy, sorption and ζ-potential measurements. The surface area increased with synthesis time, whilst the Ce3+/Ce4+ ratio scales inversely with decreasing ζ-potential. In this way the catalytic activity of mesoporous CeO2−x particles could be tailored selectively for haloperoxidase- and peroxidase-like reactions. The ease of tuning the surface properties of mesoporous CeO2x particles by varying the synthesis time makes the synthesis a powerful general tool for the preparation of nanocatalysts according to individual needs. KW - SAXS KW - Ceria KW - Zeta potential PY - 2022 DO - https://doi.org/10.1039/D2NR03172H SP - 1 EP - 12 PB - Royal Society of Chemistry AN - OPUS4-55649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grunert, B. A1 - Saatz, Jessica A1 - Hoffmann, Katrin A1 - Appler, F. A1 - Lubjuhn, Dominik A1 - Jakubowski, Norbert A1 - Resch-Genger, Ute A1 - Emmerling, Franziska A1 - Briel, A. T1 - Multifunctional rare-earth element nanocrystals for cell labeling and multimodal imaging N2 - In this work, we describe a simple solvothermal route for the synthesis of Eu3+-doped gadolinium orthovanadate nanocrystals (Eu:GdVO4−PAA) functionalized with poly(acrylic)acid (PAA), that are applicable as cell labeling probes for multimodal cellular imaging. The Eu3+ doping of the vanadate matrix provides optical functionality, due to red photoluminescence after illumination with UV light. The Gd3+ ions of the nanocrystals reduce the T1 relaxation time of surrounding water protons, allowing these nanocrystals to act as a positive MRI contrast agent with a r1 relaxivity of 1.97 mM−1 s−1. Low background levels of Eu3+, Gd3+, and V5+ in biological systems make them an excellent label for elemental microscopy by Laser Ablation (LA)-ICP-MS. Synthesis resulted in polycrystalline nanocrystals with a hydrodynamic diameter of 55 nm and a crystal size of 36.7 nm, which were further characterized by X-ray diffraction (XRD), photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The multifunctional nanocrystals were subsequently used for intracellular labeling of both human adipose-derived stem cells (MSCs) and A549 (adenocarcinomic human alveolar basal epithelial) cells. KW - Bioimaging KW - Nanoparticle KW - Multimodal KW - Lanthanide PY - 2018 DO - https://doi.org/10.1021/acsbiomaterials.8b00495 SN - 2373-9878 VL - 4 IS - 10 SP - 3578 EP - 3587 PB - ACS Publications CY - Washington, USA AN - OPUS4-46244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical reactions N2 - Presentation of the recent results in the context of in situ investigations of reactions using X-ray diffraction. T2 - Germany Brazil Workshop: New light on mechanisms of chemical reactions CY - Kiel, Germany DA - 31.07.2018 KW - In situ KW - XRD PY - 2018 AN - OPUS4-46991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -