TY - CONF A1 - Temgoua, Ranil C. T. T1 - Understanding the behavior of phenylurazoletyrosine- click electrochemical reaction N2 - The electrochemical behavior of 4-phenylurazole (Ph-Ur) was studied and the latter was used as a molecular anchor for the electrochemical bioconjugation of tyrosine (Y). Cyclic voltammetry (CV) and controlled potential coulometry (CPC) allowed to generate in situ from phenylurazole the PTAD (4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione) species on demand for tyrosine electrolabeling. To evaluate the performance of tyrosine electrolabeling, coulometric analyses at controlled potentials were performed on solutions of phenylurazole and the phenylurazole-tyrosine mixture in different proportions (2:1, 1:1, and 1:2). The electrolysis of the phenylurazole-tyrosine mixture in the ratio (1:2) produced a charge of 2.07 C, very close to the theoretical value (1.93 C) with high reaction kinetics, a result obtained here for the first time. The products obtained were identified and characterized by liquid chromatography coupled to high-resolution electrospray ionization mass spectrometry (LC-HRMS and LC-HRMMS). Two products were formed from the click reactions, one of which was the majority. Another part of this work was to study the electrochemical degradation of the molecular anchor 4-phenylazole (Ph-Ur). Four stable degradation products of phenylurazole were identified (C7H9N2O, C6H8N, C6H8NO, C14H13N4O2) based on chromatographic profiles and mass spectrometry results. The charge generated during the electrolysis of phenylurazole (two-electron process) (2.85 C) is inconsistent with the theoretical or calculated charge (1.93 C), indicating that secondary/parasitic reactions occurred during the electrolysis of the latter. In conclusion, the electrochemically promoted click phenylurazole-tyrosine reactions give rise to click products with high reaction kinetics and yields in the (1:2) phenylurazole-tyrosine ratios, and the presence of side reactions is likely to affect the yield of the click phenylurazole-tyrosine reaction. T2 - Les Journées d’Électrochimie 2024 CY - Saint-Malo, France DA - 01.07.2024 KW - Electrochemistry KW - Mass Spectrometry KW - Simulation PY - 2024 AN - OPUS4-61063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Temgoua, Ranil C. T. T1 - Mimicking Environmental Degradation of Carbendazim Pesticide by EC-MS N2 - Currently, there is a growing interest in the study of environmental degradation pathways of organic contaminants such as pesticides, with the objective to better understand their potential risk for environmental systems and living organisms. In this context, DFT (conceptual density functional theory) and predictive methods may systematically be used to simplify and accelerate the elucidation of environmental degradation. We report herein the electrochemical behavior/degradation of the carbendazim (CBZ) fungicide widely used to treat cereal and fruit crops. Oxidative degradation of CBZ was studied using an electrochemical flow-through cell directly coupled to a mass spectrometer for rapid identification of CBZ degradation products. The structural elucidation of CBZ oxidation products was based on retention time, accurate mass, isotopic distribution and fragmentation pattern by using LC-HRMS an LC-HRMS2. The most important chemical reactions found to occur in the transformation of CBZ were hydrolysis and hydroxylation. EC-LC-MS and EC-MS analysis has made it possible to highlight the identification of degradation products of CBZ. In addition to previously known transformation products common to those observed during environmental degradation (monocarbomethoxyguanidine, benzimidazole-isocyanate, 2-aminobenzimidazole, hydroxy-2-aminobenzimidazole, hydroxycarbendazim, CBZ-CBZ dimer), two new degradation products were identified in this work: a quinone imine and a nitrenium ion. Electrochemistry mass spectrometry hyphenated techniques represent an accessible, rapid and reliable tool to elucidate the oxidative degradation of CBZ, including reactive degradation products and conjugates. T2 - 36th Topical Meeting of the International Society of Electrochemistry CY - Šibenik, Croatia DA - 26.05.2024 KW - Electrochemistry KW - Mass Spectrometry KW - Emerging pollutants KW - Transformation products PY - 2024 AN - OPUS4-61062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertural, Christina T1 - Phonon-accurate machine-learning potentials from automated workflows N2 - Data-driven materials design aims to predict and optimize material properties, such as stability and thermal conductivity, which are influenced by vibrational behavior. Approaches like DFT are computationally demanding and have limitations for phonon calculations. Machine learning-driven interatomic potentials (MLIP), like the Gaussian approximation potential (GAP), offer a more efficient alternative.1–8 We developed a Python workflow to automate MLIP generation using the Materials Project database.9 DFT computations, MLIP fitting and benchmark steps are automated.10,11 This approach accelerates phonon calculations and supports testing different data generation strategies and hyperparameters, and further validation12 is planned. Our goal is to provide open-source code and share these potentials. T2 - Faraday Discussions: Data-driven discovery in the chemical sciences CY - Oxford, UK DA - 10.09.2024 KW - Interatomic potentials KW - Machine learning KW - Phonons KW - Thermoelectrics PY - 2024 AN - OPUS4-61061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy T1 - 1H NMR Relaxometry: A Reliable Tool for Predicting Durability Properties? N2 - Resistance to carbonation and chloride migration are critical durability properties in cementitious construction materials. The ingress of CO2 and chlorides can lead to concrete deterioration and reinforcement corrosion, underscoring the importance of ensuring high resistance to these durability-reducing factors. Traditional methods, such as determinating the carbonation coefficient using standard procedures, are time-consuming and resource-intensive. These tests typically require 42 days of preconditioning, followed by 70 days before the final results can be determined using a phenolphthalein test, for a total duration of 112 days. In addition, some test chambers can only accommodate four samples at a time. In this study, we investigate whether 1H NMR relaxometry can effectively predict not only the carbonation resistance, KAC,3%, but also the chloride migration coefficient, DRCM, and the compressive strength, fc, of concrete, providing a method that could potentially streamline and accelerate the material development process by directing us quickly to potentially well-suited formulations. We performed measurements on non-carbonated fully saturated concrete and mortar samples at 28, 56, and 92 days using the NMR tomograph at BAM (8.9 MHz). Notably, the NMR measurements taken at 28 days showed no significant differences, suggesting that this timeframe is sufficient for meaningful results. The samples analyzed were drill cores, each 70 mm in diameter and approximately 120 mm in height. The NMR features we focused on included the initial amplitude E0, the x and y values of the dominant T2 relaxation time, and the logarithmic mean of the T2 relaxation time distribution. Another key feature was the surface relaxivity, which was determined by comparing the NMR curves with results from mercury intrusion porosimetry. We examined the correlation of these NMR features with the aforementioned durability properties, which were determined in a laboratory on sister samples using standard procedures. No chloride migration tests were performed on the mortar samples, and the carbonation procedure was carried out unter atmospheric conditions. The preliminary results show that the correlation factors for the NMR features with the carbonation coefficients of concrete were particularly remarkable. The strongest correlations were observed for the dominant relaxation time and the logarithmic mean, with values approaching 1. The preliminary results also indicate that there are high correlations between the compressive strength and amplitude-related features. In contrast, no strong correlations are observed for the DRCM. Although the results related to the mortar samples are still being analyzed, these initial correlations suggest that 1H NMR relaxometry could be a valuable tool for early assessment of material properties. Furthermore, the rapid and non-destructive nature of NMR measurements, requiring only a few minutes per sample, suggests that this technique has the potential to significantly accelerate the process of evaluating durability properties in cementitious materials. This capability also paves the way for the use of NMR features as input for AI-driven predictive models. T2 - Magnetic Resonance in Porous Media 2024 CY - Tromso, Norway DA - 26.08.2024 KW - Nuclear magnetic resonance KW - SLAMD KW - Carbonation KW - Durability PY - 2024 AN - OPUS4-61058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Traub, Heike T1 - LA-ICP-MS investigation of the the interaction of MRI contrast agents with extracellular matrix components N2 - In clinical magnetic resonance imaging, non-specific Gd-based contrast agents (GBCAs) are frequently used to improve image quality. However, the interaction of GBCAs with tissue components is not yet fully understood. Many diseases, including inflammation, fibrosis, and tumor invasion, are associated with characteristic changes of the extracellular matrix (ECM). The ECM is a three-dimensional scaffold that embeds the cells of all mammalian tissues. It is composed of structural proteins (e.g., collagen, elastin) and proteoglycans, which consist of glycosaminoglycans (GAGs) covalently bound to a protein core. GAGs are characterized by their ability to form complexes with cations such as lanthanides. Thus, GAGs could be a potential binding partner for GBCAs as a whole or for dechelated Gd. Laser ablation inductively coupled plasma time-of-flight mass spectrometry (LA/ICP-ToF-MS) was used to investigate the uptake and distribution of different GBCAs in spheroids mimicking biological tissue and exhibiting different ECM expressions. Spheroids from Chinese hamster ovary (CHO) cells and GAG-depleted CRL-2242 cells were incubated with gadolinium chloride and various linear and macrocyclic GBCAs. Although all spheroids were exposed to identical Gd concentrations, differences in the amount of Gd taken up were observed. Gadolinium chloride is more strongly absorbed and accumulates mainly in the outer regions of the spheroids. In contrast, after incubation with linear and macrocyclic GBCAs, Gd is detected in the interior of both types of spheroids. Furthermore, differences in the Gd amount were found depending on the GBCA used. However, further studies are needed to elucidate such complex interactions, also using other (bio)analytical techniques. T2 - 2nd Annual Conference on Mass Spectrometry Imaging and Integrated Topics, IMSIS-2024 CY - Münster, Germany DA - 09.09.2024 KW - ICP-MS KW - Laser ablation KW - Contrast agent KW - Spheroid KW - Extracellular matrix PY - 2024 AN - OPUS4-61049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolf, Christoph T1 - Optimization Framework for Powder Bed 3D Printed Concrete Structures under Various Constraints N2 - The fusion of 3D printing with concrete has transformed large scale construction, accelerating creative design possibilities. In recent years, multiple printing techniques have been developed and are still under investigation. The powder bed technique enables overhang constructions, thereby increasing design flexibility. To maximize the advantages of those printing techniques, a holistic approach is required taking topology optimization through finite element analysis into account. The challenge is to consider a range of constraints, from material to geometrical to manufacturing. The current research focuses on the development of a holistic approach to large-scale 3D powder bed printed concrete structure optimization, navigating the in-tricacies of constraints, leveraging the advantages of powder-based printers, and integrating essential information from material tests. A workflow starting from geometry input and ending with printing instructions is derived, minimizing user interaction, and offering fast and reliable results for different structures. Starting from a geometric model of the global design with the required load cases, the geometry is optimized with respect to reduce the mass and thus CO2 emissions. Thereby, the topology optimization includes various constraints: stress con-straints (mitigating tension and limit compressive stress using Drucker-Prager based models), geometric constraints (preserving specific surfaces from optimi-zation), and manufacturing constraints (controlling member size and avoiding trapped powder). Different objective functions, like minimizing compliance or mass are considered in this study. The process receives input from upstream ma-terial tests, offering insights into strength, stiffness and possible anisotropy. This integration of material testing enhances the accuracy and reliability of the opti-mization, aligning the design with real-world behavior of 3D printed concrete. An important aspect of the workflow is the segmentation of the optimized global structure into substructures, aligning with the size limitations of the 3D powder-bed printer. As final output of the developed workflow, printer specific fabrica-tion instructions are generated for each substructure. The developed optimization framework is demonstrated in the design of a multiperson shading element. T2 - 4th RILEM International Conference on Concrete and Digital Fabrication CY - Munich, Germany DA - 04.09.2024 KW - Topology Optimization KW - Powder Bed 3D Printing KW - Segmentation and Substructure KW - Modelling KW - Material Testing PY - 2024 AN - OPUS4-61021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Seasonal microplastic concentrations along the rivers Rhine and Danube N2 - Over the last 20 years, many researchers, politicians and citizens have become increasingly aware of the growing plastic problem of our time. A lack of recycling concepts and plastic collection points as well as careless dumping lead to accumulation of plastic products in the environment. Natural weathering can cause these plastics to degrade and fractionate, meaning that microplastics (1 1,000 µm, ISO/TR 21960:2020) and nanoplastics (< 1 µm, ISO/TR 21960:2020) of various synthetic polymer materials can now be detected in all parts of the world. Whether microplastics or nanoplastics pose a toxicological hazard is being investigated in a variety of ways. Valid results are still pending. However, the EU precautionary principle applies to micro- and nanoplastics. Monitoring of microplastics is already required in the revision of the Drinking Water and Wastewater Framework Directive. Reliable monitoring of rivers can be carried out by sampling with sedimentation boxes and microplastic detection by using thermal extraction desorption gas chromatography/mass spectrometry (TED-GC/MS) in routine operation (Figure 1). The river Rhine was sampled for microplastic masses at three different sampling locations over a period of one year and in addition the Danube at randomized sampling locations The TED-GC/MS results showed that various synthetic polymers frequently produced in industry, such as polyethylene, polypropylene or polystyrene as well as the tire compound styrene-butadiene rubber were found. The work not only shows a possible workflow for monitoring concepts, but also provides information on environmentally relevant concentrations of microplastics and tire components in surface waters. This in turn is necessary for ecotoxicological studies. T2 - ESOPS CY - Berlin, Germany DA - 09.09.2024 KW - Microplastics KW - TED-GC/MS KW - Polymer 3R PY - 2024 AN - OPUS4-61016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Rudolf J. T1 - Spurenstoffe im Rohabwasser: Möglichkeiten und Perspektiven für den One-Health-Ansatz N2 - Der One-Health-Ansatz hat die Gesundheit von Mensch, Tier und Umwelt im Fokus. Dazu ist eine interdisziplinäre Zusammenarbeit von Akteuren aus Human- und Veterinärmedizin sowie den Umweltwissenschaften notwendig. Ein Ineinandergreifen von methodischen Ansätzen und der Analytik wird angestrebt. Im Zuge der anstehenden Novellierung (2924) der EU-Kommunalabwasserrichtlinie (91/271/EWG) wird die Umsetzung eines One-Health-Ansatzes bereits adressiert. Dazu gehört zum einen der Ausbau und die Prozessüberwachung einer vierten Reinigungsstufe in Klärwerken. Zum anderen ist europaweit die Infrastruktur einer Abwassersurveillance zur Überwachung von Krankheitserregern zu gewährleisten. Dies wird aktuell in Deutschland mit dem Projekt AMELAG ("Abwassermonitoring zur epidemiologischen Lagebewertung") mit zwei Probennahmen pro Woche auf ca. 170 Kläranlagen umgesetzt. T2 - 6. Mülheimer Wasseranalytisches Seminar (MWAS 2024) CY - Mülheim an der Ruhr, Germany DA - 10.09.2024 KW - ELISA KW - Spurenstoffe KW - Koffein KW - Carbamazepin KW - Diclofenac KW - Immunoassay PY - 2024 AN - OPUS4-60993 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Exner, T. T1 - Evaluation anthropogener Marker als Normalisierungsfaktoren für die SARS-CoV-2 Abwassersurveillance zur epidemiologischen Lagebewertung N2 - Im Rahmen der weltweiten Corona-Pandemie fordert die EU-Kommission seit März 2021 die systematische Erfassung und Überwachung von SARS-CoV-2 über das Abwasser, welche der Entscheidungsfindung bezüglich bevölkerungsbezogener Maßnahmen dienen soll. Hierbei können Trendanalysen für die epidemiologische Lagebewertung abgeleitet werden, sofern ein großer Anteil des kommunalen Abwassers der Bevölkerung durch das Monitoring abdeckt wird. Die Datenerhebung erfolgt somit unabhängig vom individuellen Test- und Meldeverhalten der Bevölkerung. Eine bedeutende Herausforderung bei der Bestimmung der Gensequenzen mittels polymerase chain reaction (PCR) stellen standortabhängige Faktoren des Einzugsgebietes sowie Schwankungen der Durchflussrate und der Abwasserzusammensetzung dar. Zu den möglichen Ursachen zählen Verdünnungseffekte durch Regen- und Schmelzwasser, Größenunterschiede des kommunalen Entwässerungssystems, Veränderungen der Demografie und Zuflüsse von Indirekteinleitern. Um eine verbesserte Korrelation quantitativ ermittelter Genkopien des SARS-CoV-2 aus der jeweiligen Abwasserprobe mit dem Anteil der infizierten Bevölkerung zu erzeugen, ist eine Normalisierung der PCR Daten vorzunehmen. Neben relativ einfach zu ermittelnden physikalischen Größen, wie der mittleren Durchflussrate oder der Leitfähigkeit, die Aufschlüsse über den Anteil von Fremd- und Regenwasser ermöglichen, können auch anthropogene Marker, wie Spurenstoffe und Surrogatviren im Abwasser, als direkte Indikatoren für menschliche Fäkalien aus dem häuslichen Abwasser dienen. Im Folgenden soll eine vergleichende Untersuchung von vier Spurenstoffen ‒ Koffein (CAF), Carbamazepin (CBZ), Diclofenac (DCF), Isolithocholsäure (ILA) ‒ sowie einem Surrogatvirus (SV) (Pepper mild mottle virus (PMMoV) oder CrAssphage), die Eignung der jeweiligen Paramater als Normalisierungsfaktoren analysieren. Die Untersuchung fand an 19 Standorten über drei Monate im Rahmen einer Studie aus dem Projekt ESI-CorA statt. T2 - Wasser 2024 (Jahrestagung der Wasserchemischen Gesellschaft der GDCh) CY - Limburg an der Lahn, Germany DA - 06.05.2024 KW - ELISA KW - Immunoassay PY - 2024 AN - OPUS4-60992 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seifert, Lando T1 - Weathering campaigns for a marine corrosion atlas N2 - Germany has set itself the task to become a world leader in the field of green hydrogen technologies and is promoting the transition to a hydrogen economy. The H2Mare flagship project is exploring the offshore production of green hydrogen and other power-to-X products. One of the most important goals is the safe and cost-efficient operation of offshore infrastructures, where a service life of at least 25 years is aimed. However, the corrosive environment towards metallic materials presents challenges in marine areas. The atmosphere at one location could be affected by the distance to the sea level and does not have the same corrosivity for all exposed kinds of materials. The creation of an atmosphere corrosion atlas for marine environments by weathering campaigns aims to close this gap. Operators of offshore structures can use the data to estimate the corrosivity of the atmosphere on the construction site. This allows planning to be optimized in terms of platform safety as well as maintenance costs. T2 - Conference EUROCORR 2024 CY - Paris, France DA - 01.09.2024 KW - Offshore Corrosion KW - Marine Corrosion KW - Corrosivity KW - Green Hydrogen KW - Power-to-X PY - 2024 AN - OPUS4-60989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -