TY - JOUR A1 - Mazzeo, P. P. A1 - Prencipe, M. A1 - Feiler, Torvid A1 - Emmerling, Franziska A1 - Bacchi, A. T1 - On the mechanism of cocrystal mechanochemical reaction via low melting eutectic: A time-resolved in situ monitoring investigation N2 - Mechanochemistry has become a sustainable and attractive cost-effective synthetic technique, largely used within the frame of crystal engineering. Cocrystals, namely, crystalline compounds made of different chemical entities within the same crystal structure, are typically synthesized in bulk via mechanochemistry; however, whereas the macroscopic aspects of grinding are becoming clear, the fundamental principles that underlie mechanochemical cocrystallization at the microscopic level remain poorly understood. Time-resolved in situ (TRIS) monitoring approaches have opened the door to exceptional detail regarding mechanochemical reactions. We here report a clear example of cocrystallization between two solid coformers that proceeds through the formation of a metastable low melting binary eutectic phase. The overall cocrystallization process has been monitored by time-resolved in situ (TRIS) synchrotron X-ray powder diffraction with a customized ball milling setup, currently available at μ Spot beamline at BESSY-II, Helmholtz-Zentrum Berlin. The binary system and the low melting eutectic phase were further characterized via DSC, HSM, and VT-XRPD. KW - Mechanochemistry KW - In situ KW - Cocrystal PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552977 DO - https://doi.org/10.1021/acs.cgd.2c00262 SN - 1528-7505 VL - 22 IS - 7 SP - 4260 EP - 4267 PB - ACS Publ. CY - Washington, DC AN - OPUS4-55297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pakrashy, S. A1 - Mandal, P. K. A1 - Goswami, J. N. A1 - Dey, S. K. A1 - Choudhury, S. M. A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Alasmary, F. A. A1 - Dolai, M. T1 - Bioinformatics and Network Pharmacology of the First Crystal Structured Clerodin: Anticancer and Antioxidant Potential against Human Breast Carcinoma Cell N2 - Clerodin was isolated from the medicinal plant Clerodendrum infortunatum, and CSD search showed the first crystal structure of clerodin by a single-crystal X-ray diffraction study. We checked its binding potential with target proteins by docking and conducted network pharmacology analysis, ADMET analysis, in silico pathway analysis, normal mode analysis (NMA), and cytotoxic activity studies to evaluate clerodin as a potential anticancer agent. The cell viability studies of clerodin on the human breast carcinoma cell line (MCF-7) showed toxicity on MCF-7 cells but no toxicity toward normal human lymphocyte cells (HLCs). The anticancer mechanism of clerodin was validated by its enhanced capacity to produce intracellular reactive oxygen species (ROS) and to lower the reduced glutathione content in MCF-7 cells. KW - Anticancer KW - Clerodin PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567600 DO - https://doi.org/10.1021/acsomega.2c07173 SN - 2470-1343 VL - 7 IS - 51 SP - 48572 EP - 48582 PB - ACS Publ. CY - Washington, DC AN - OPUS4-56760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abusafia, A. A1 - Scheid, C. A1 - Meurer, Maren A1 - Altmann, Korinna A1 - Dittmer, U. A1 - Steinmetz, H. T1 - Microplastic sampling strategies in urban drainage systems for quantification of urban emissions based on transport pathways N2 - Tracking waterborne microplastic (MP) in urban areas is a challenging task because of the various sources and transport pathways involved. Since MP occurs in low concentrations in most wastewater and stormwater streams, large sample volumes need to be captured, prepared, and carefully analyzed. The recent research in urban areas focused mainly on MP emissions at wastewater treatment plants (WWTPs), as obvious entry points into receiving waters. However, important transport pathways under wet-weather conditions are yet not been investigated thoroughly. In addition, the lack of comprehensive and comparable sampling strategies complicated the attempts for a deeper understanding of occurrence and sources. The goal of this paper is to (i) introduce and describe sampling strategies for MP at different locations in a municipal catchment area under dry and wet-weather conditions, (ii) quantify MP emissions from the entire catchment and two other smaller ones within the bigger catchment, and (iii) compare the emissions under dry and wet-weather conditions. WWTP has a high removal rate of MP (>96%), with an estimated emission rate of 189 kg/a or 0.94 g/[population equivalents (PEQ · a)], and polyethylene (PE) as the most abundant MP. The specific dry-weather emissions at a subcatchment were ≈30 g/(PEQ · a) higher than in the influent of WWTP with 23 g/(PEQ · a). Specific wet-weather emissions from large sub-catchment with higher traffic and population densities were 1952 g/(ha · a) higher than the emissions from smaller catchment (796 g/[ha · a]) with less population and traffic. The results suggest that wet-weather transport pathways are likely responsible for 2–4 times more MP emissions into receiving waters compared to dry-weather ones due to tire abrasion entered from streets through gullies. However, more investigations of wet-weather MP need to be carried out considering additional catchment attributes and storm event characteristics. KW - Combined sewer system KW - Large volume samplers KW - Microplastic pollution KW - Separate sewer system KW - Stormwater retention tank PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568271 DO - https://doi.org/10.1002/appl.202200056 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goedecke, C. A1 - Eisentraut, Paul A1 - Altmann, Korinna A1 - Elert, Anna Maria A1 - Bannick, C. G. A1 - Ricking, M. A1 - Obermaier, N. A1 - Barthel, A.-K. A1 - Schmitt, T. A1 - Jekel, M. A1 - Braun, U. T1 - Development of a routine screening method for the microplastic mass content in a wastewater treatment plant effluent N2 - An investigation of microplastic (MP) occurrence in a municipal wastewater treatment plant (WWTP) effluent with tertiary treatment was carried out. Representative sample volumes of 1 m3 were taken by applying a fractionated filtration method (500, 100, and 50 µm mesh sizes). The detection of MP mass fractions by thermal extraction desorption–gas chromatography/mass spectrometry (TED-GC/MS) was achieved without the previously required additional sample pretreatment for the first time. Different types of quantification methods for the evaluation of TED-GC/MS data were tested, and their accuracy and feasibility have been proven for real samples. Polyethylene, polystyrene, and polypropylene were identified in effluent samples. The polymer mass content varied significantly between 5 and 50 mg m−3. A correlation between the MP load and the quantity of suspended matter in the WWTP effluents, particle size distribution, particle type, and operation day (i.e., weekday, season, and capacity) was not found. It can be concluded that a meaningful assessment of WWTPs requires a comprehensive sampling campaign with varying operation conditions. KW - Microplastic KW - Waste water treatment KW - Thermoanalytics PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-550862 DO - https://doi.org/10.3389/fenvc.2022.844633 SN - 2673-4486 VL - 3 SP - 1 EP - 10 PB - Frontiers Media CY - Lausanne AN - OPUS4-55086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, S. A1 - Horstmann, J. A1 - Altmann, Korinna A1 - Braun, U. A1 - Hagendorf, C. T1 - A reference methodology for microplastic particle size distribution analysis: Sampling, filtration, and detection by optical microscopy and image processing N2 - Microplastic (MP) contamination in natural water circulation is a concern for environmental issues and human health. Various types of polymer materials have been identified and were detected in MP analytic test procedures. Beyond MP polymer type, particle size and form play a major role in water analysis due to possible negative toxicologic effects on flora and fauna. However, the correct quantitative measurement of MP size distribution over several orders of magnitude is strongly influenced by sample preparation, filtration materials and processes, and microanalytical techniques, as well as data acquisition and analysis. In this paper, a reference methodology is presented aiming at an improved quantitative analysis of MP particles. An MP analysis workflow is demonstrated including all steps from reference materials to sample preparation, filtration handling, and MP particle size distribution analysis. Background-corrected particle size distributions (1–1000 µm) have been determined for defined polyethylene (PE) and polyethylene terephthalate (PET) reference samples. Microscopically measured particle numbers and errors have been cross-checked with the total initial mass. In particular, defined reference MP samples (PE, PET) are initially characterized and applied to filtration experiments. Optical microscopy imaging on full-area Si filters with subsequent image analysis algorithms is used for statistical particle size distribution analysis. To quantify the effects of handling and filtration, several blind tests with distilled water are carried out to determine the particle background for data evaluation. Particle size distributions of PE and PET reference samples are qualitatively and quantitatively reproduced with respect to symmetry, and maximum and cut-off diameter of the distribution. It is shown that especially MP particles with a radius of >50 µm can be detected and retrieved with high reliability. For particle sizes <50 µm, a significant interference with background contamination is observed. Data from blank samples allows a correction of background contaminations. Furthermore, for enhanced sampling statistics, the recovery of the initial amount of MP will be qualitatively shown. The results are intended as an initial benchmark for MP analytics quality. This quality is based on statistical MP particle distributions and covers the complete analytic workflow starting from sample preparation to filtration and detection. Microscopic particle analysis provides an important supplement for the evaluation of established spectroscopic methods such as Fourier-transform infrared spectroscopy or Raman spectroscopy. KW - Drinking water KW - Filtration KW - Microplastics detection KW - Quality control KW - Statistical particle distribution PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567625 DO - https://doi.org/10.1002/appl.202200055 SN - 2702-4288 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-56762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rautenberg, Max A1 - Bhattacharya, Biswajit A1 - Witt, Julia A1 - Jain, Mohit A1 - Emmerling, Franziska T1 - In situ time-resolved monitoring of mixed-ligand metal–organic framework mechanosynthesis N2 - The mechanism of mixed-ligand metal–organic framework (MOF) formation, and the possible role of intermediate single-ligand metal complexes during mechanosynthesis, have not been explored yet. For the first time, we report here in situ real-time monitoring of the mechanochemical formation mechanism of mixed-ligand MOFs. Our results show that binary phases can act as intermediates or competing products in one-pot and stepwise synthesis. KW - Mechanochemistry KW - Metal-organic-frameworks KW - In situ X-ray diffraction KW - Mixed-ligand MOFs PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558167 DO - https://doi.org/10.1039/D2CE00803C SP - 1 EP - 4 PB - Royal Society of Chemistry AN - OPUS4-55816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Hoch, C. T1 - Laudatio Prof. Dr.-Ing. Caroline Röhr N2 - It is a laudatio on the ocations of Prof. Dr.-Ing. Caroline Röhrs 60th birthday. KW - Metal-oxides PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561877 DO - https://doi.org/10.1002/zaac.202200159 SN - 0044-2313 VL - 648 IS - 10 SP - 1 EP - 2 PB - John Wiley & Sons, Ltd AN - OPUS4-56187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kadri, Lena A1 - Casali, Lucia A1 - Emmerling, Franziska A1 - Tajber, Lidia T1 - Mechanochemical comparison of ball milling processes for levofloxacin amorphous polymeric systems N2 - This study aimed to investigate the amorphization capabilities of levofloxacin hemihydrate (LVXh), a fluoroquinolone drug, using a polymer excipient, Eudragit® L100 (EL100). Ball milling (BMing) was chosen as the manufacturing process and multiple mill types were utilized for comparison purposes. The product outcomes of each mill were analyzed in detail. The solid-state of the samples produced was comprehensively characterized by Powder X-ray Diffraction (PXRD), In-situ PXRD, Differential Scanning Calorimetry (DSC), Solid-State Fourier Transform Infrared Spectroscopy (FT-IR), and Dynamic Vapor Sorption (DVS). The crystallographic planes of LVXh were investigated by in-situ PXRD to disclose the presence or absence of weak crystallographic plane(s). The mechanism of LVXh:EL100 system formation was discovered as a two-step process, first involving amorphization of LVXh followed by an interaction with EL100, rather than as an instantaneous process. DVS studies of LVXh:EL100 samples showed different stability properties depending on the mill used and % LVXh present. Overall, a more sustainable approach for achieving full amorphization of the fluoroquinolone drug, LVXh, was accomplished, and advancements to the fast-growing world of pharmaceutical mechano- and tribo-chemistry were made. KW - Levofloxacin KW - Eudragit® L100 KW - Mechanochemistry KW - Phase transformation KW - In situ monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611129 DO - https://doi.org/10.1016/j.ijpharm.2024.124652 SN - 0378-5173 VL - 665 SP - 1 EP - 16 PB - Elsevier B.V. AN - OPUS4-61112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baláž, Matej A1 - Birinci, Mustafa A1 - Şentürk, Kader A1 - Achimovičová, Marcela A1 - Baláž, Peter A1 - Tampubolon, Imelda Octa A1 - Stolar, Tomislav A1 - Bienert, Ralf A1 - Emmerling, Franziska A1 - Erdemoğlu, Sema A1 - Sis, Hikmet A1 - Erdemoğlu, Murat T1 - Utilizing Taguchi method and in situ X-ray powder diffraction monitoring to determine the influence of mechanical activation conditions on the physico-chemical properties and Al leachability of K-feldspar N2 - K-feldspar represents an important natural resource of potassium and aluminum. Within the framework of this study, the K-feldspar was mechanically activated in a planetary ball mill under different conditions planned according to 43 Taguchi orthogonal array experimental design. As outputs, specific surface area (SBET), median particle size (d50), amorphization degree of mineral phases , and Al recovery were used. It was found that the initial d50 value of 293 μm could be reduced to 6.7 μm and the SBET value of 4.7 m2/g could be increased up to 32.5 m2/g upon milling. Both microcline KAl3SiO8, and albite NaAl3SiO8 could be almost completely amorphized, whereas quartz SiO2 still maintained some crystallinity even under the most intensive conditions. Increasing SBET and decreasing the d50 values did not lead to a significant improvement in Al leach recovery, whereas a clear relationship between the amorphization of microcline and the recovered aluminum was found. Analysis of Variance (ANOVA) showed that increasing ball-to-powder ratio is the most beneficial for the improvement in Al recovery. In situ powder X-ray diffraction monitoring performed in an oscillation ball mill under synchrotron irradiation has shown very rapid amorphization of microcline phase at the beginning. However, amorphization of microcline was only partial after two hours of the treatment in this mill, apart from almost complete process in the planetary ball mill. In the end, regressions for the calculation of Al recovery by knowing the values of input parameters were calculated. In general, by just using mechanical activation without the subsequent roasting process that is commonly used to boost metal recoveries, it was possible to quantitatively recover aluminum from K-feldspar. KW - Mechanochemistry KW - Mechanical activation KW - Design of experiments PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611059 DO - https://doi.org/10.1016/j.jmrt.2024.08.156 SN - 2238-7854 VL - 32 SP - 3886 EP - 3895 PB - Elsevier B.V. AN - OPUS4-61105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cakir, Cafer Tufan A1 - Bogoclu, Can A1 - Emmerling, Franziska A1 - Streli, Christina A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin T1 - Machine learning for efficient grazing-exit x-ray absorption near edge structure spectroscopy analysis: Bayesian optimization approach N2 - In materials science, traditional techniques for analyzing layered structures are essential for obtaining information about local structure, electronic properties and chemical states. While valuable, these methods often require high vacuum environments and have limited depth profiling capabilities. The grazing exit x-ray absorption near-edge structure (GE-XANES) technique addresses these limitations by providing depth-resolved insight at ambient conditions, facilitating in situ material analysis without special sample preparation. However, GE-XANES is limited by long data acquisition times, which hinders its practicality for various applications. To overcome this, we have incorporated Bayesian optimization (BO) into the GE-XANES data acquisition process. This innovative approach potentially reduces measurement time by a factor of 50. We have used a standard GE-XANES experiment, which serve as reference, to validate the effectiveness and accuracy of the BO-informed experimental setup. Our results show that this optimized approach maintains data quality while significantly improving efficiency, making GE-XANES more accessible to a wider range of materials science applications. KW - Machine Learning KW - GE-XANES KW - Bayesian Optimization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603955 DO - https://doi.org/10.1088/2632-2153/ad4253 VL - 5 IS - 2 SP - 1 EP - 12 PB - IOP Publishing AN - OPUS4-60395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dittmar, Stefan A1 - Ruhl, Aki S. A1 - Altmann, Korinna A1 - Jekel, Martin T1 - Settling Velocities of Small Microplastic Fragments and Fibers N2 - There is only sparse empirical data on the settling velocity of small, non-buoyant microplastics thus far, although it is an important parameter governing their vertical transport within aquatic environments. This study reports the settling velocities of 4031 exemplary microplastic particles. Focusing on the environmentally most prevalent particle shapes, irregular microplastic fragments of four different polymer types (9–289 µm) as well as five discrete length fractions (50–600 µm) of common nylon and polyester fibers were investigated, respectively. All settling experiments were carried out in quiescent water using a specialized optical imaging setup. The method has been previously validated in order to minimize disruptive factors, e.g. thermal convection or particle interactions, and thus enable the precise measurements of the velocities of individual microplastic particles (0.003–9.094 mm/s). Based on the obtained data, ten existing models for predicting a particle’s terminal settling velocity were assessed. It is concluded that models, which were specifically deduced from empirical data on larger microplastics, fail to provide accurate predictions for small microplastics. Instead, a different approach is highlighted as a viable option for computing settling velocities across the microplastics continuum in terms of size, density and shape. KW - Microplastics KW - Microplastic fibers KW - Settling velocity KW - Sinking velocity KW - Sedimentation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597455 DO - https://doi.org/10.1021/acs.est.3c09602 SN - 0013-936X VL - 58 IS - 14 SP - 6359 EP - 6369 PB - American Chemical Society (ACS) AN - OPUS4-59745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Coburger, Peter A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Abbenseth, Josh T1 - Combining geometric constraint and redox non-innocence within an ambiphilic PBiP pincer ligand N2 - The first pincer ligand featuring a strictly T-shaped pnictogen donor moiety was synthesised. The PBiP ligand's redox activity facilitates unprecedented ambiphilic bonding of the Bi centre with transition metals through the Bi(6p) orbital. KW - EXAFS KW - Pincer Ligand KW - Group 15 metals PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611113 DO - https://doi.org/10.1039/D4SC00197D SN - 2041-6520 SP - 1 EP - 8 PB - Royal Society of Chemistry (RSC) AN - OPUS4-61111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schlögl, Johanna A1 - Goldammer, Ole A1 - Bader, Julia A1 - Emmerling, Franziska A1 - Riedel, Sebastian T1 - Introducing AFS ([Al(SO3F)3]x) – a thermally stable, readily available, and catalytically active solid Lewis superacid N2 - This paper introduces the thermally stable, solid Lewis superacid aluminium tris(fluorosulfate) (AFS), that is easy-to-synthesize from commercially available starting materials. Its applicability, e.g. in catalytic C–F bond activations, is shown. KW - Lewis Acid KW - C-F activation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601001 DO - https://doi.org/10.1039/D4SC01753F SN - 2041-6520 SP - 1 EP - 7 PB - Royal Society of Chemistry (RSC) AN - OPUS4-60100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senges, Gene A1 - de Oliveira Guilherme Buzanich, Ana A1 - Lindič, Tilen A1 - Gully, Tyler A. A1 - Winter, Marlon A1 - Radtke, Martin A1 - Röder, Bettina A1 - Steinhauer, Simon A1 - Paulus, Beate A1 - Emmerling, Franziska A1 - Riedel, Sebastian T1 - Unravelling highly oxidized nickel centers in the anodic black film formed during the Simons process by in situ X-ray absorption near edge structure spectroscopy N2 - The electrofluorination after Simons has been used for the last century to produce everyday life materials. An in situ XANES investigation of the controversially debated black film apparent in the Simons process revealed high-valent nickel centers. KW - Synchrotron KW - BAMline KW - XANES PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608366 DO - https://doi.org/10.1039/d3sc06081k SN - 2041-6520 VL - 15 IS - 12 SP - 4504 EP - 4509 PB - Royal Society of Chemistry (RSC) AN - OPUS4-60836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Das, Prasenjit A1 - Chakraborty, Gouri A1 - Friese, Nico A1 - Roeser, Jérôme A1 - Prinz, Carsten A1 - Emmerling, Franziska A1 - Schmidt, Johannes A1 - Thomas, Arne T1 - Heteropolyaromatic Covalent Organic Frameworks via One-Pot Multicomponent Reactions N2 - Multicomponent reactions (MCRs) offer a platform to create different chemical structures and linkages for highly stable covalent organic frameworks (COFs). As an illustrative example, the multicomponent Povarov reaction generates 2,4-phenylquinoline from aldehydes and amines in the presence of electron-rich alkenes. In this study, we introduce a new domino reaction to generate unprecedented 2,3-phenylquinoline COFs in the presence of epoxystyrene. This work thus presents, for the first time, structural isomeric COFs produced by multicomponent domino and Povarov reactions. Furthermore, 2,3-phenylquinolines can undergo a Scholl reaction to form extended aromatic linkages. With this approach, we synthesize two thermally and chemically stable MCR-COFs and two heteropolyaromatic COFs using both domino and in situ domino and Scholl reactions. The structure and properties of these COFs are compared with the corresponding 2,4-phenylquinoline-linked COF and imine-COF, and their activity toward benzene and cyclohexane sorption and separation is investigated. The position of the pendant phenyl groups within the COF pore plays a crucial role in facilitating the industrially important sorption and separation of benzene over cyclohexane. This study opens a new avenue to construct heteropolyaromatic COFs via MCR reactions. KW - COF PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604038 DO - https://doi.org/10.1021/jacs.4c02551 SP - 1 EP - 9 PB - American Chemical Society (ACS) AN - OPUS4-60403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiesner, Yosri A1 - Hoffmann, Thomas A1 - Range, David A1 - Altmann, Korinna T1 - Microplastics in sediments of the river Rhine—A workflow for preparation and analysis of sediment samples from aquatic river systems for monitoring purposes N2 - AbstractMicroplastics (MP) can be detected in all environmental systems. Marine and terrestrial aquatic systems, especially the transported suspended solids, have often been the focus of scientific investigations in the past. Sediments of aquatic river systems, on the other hand, were often ignored due to the time‐consuming sample preparation and analysis procedures. Spectroscopic measurement methods counting particle numbers are hardly suitable as detection methods, because there are plenty of natural particles next to a small number of MP particles. Integral methods, such as thermoanalytical methods are determining the particle mass independently of the inorganic components.In this study, a workflow for sample preparation via density separation and subsequent analysis by thermal extraction desorption‐gas chromatography/mass spectrometry is presented, which leads to representative and homogeneous samples and allows fast and robust MP mass content measurements suitable for routine analysis. Polymers were identified and quantified in all samples. Polyethylene and styrene‐butadiene rubber are the dominant polymers, besides polypropylene and polystyrene. Overall, total polymer masses between 1.18 and 337.0 µg/g could be determined. Highest MP concentrations in riverbed sediment are found in sites characterized by low flow velocities in harbors and reservoirs, while MP concentrations in sandy/gravelly bed sediments with higher flow velocities are small. KW - Microplastics KW - Density separation KW - TED-GC/MS KW - NaI PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597335 DO - https://doi.org/10.1002/appl.202200125 VL - 3 IS - 2 SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-59733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Janina A1 - Kaufmann, Jan Ole A1 - Weller, Michael G. T1 - Simple Determination of Affinity Constants of Antibodies by Competitive Immunoassays N2 - The affinity constant, also known as the equilibrium constant, binding constant, equilibrium association constant, or the reciprocal value, the equilibrium dissociation constant (Kd), can be considered as one of the most important characteristics for any antibody–antigen pair. Many methods based on different technologies have been proposed and used to determine this value. However, since a very large number of publications and commercial datasheets do not include this information, significant obstacles in performing such measurements seem to exist. In other cases where such data are reported, the results have often proved to be unreliable. This situation may indicate that most of the technologies available today require a high level of expertise and effort that does not seem to be available in many laboratories. In this paper, we present a simple approach based on standard immunoassay technology that is easy and quick to perform. It relies on the effect that the molar IC50 approaches the Kd value in the case of infinitely small concentrations of the reagents. A two-dimensional dilution of the reagents leads to an asymptotic convergence to Kd. The approach has some similarity to the well-known checkerboard titration used for the optimization of immunoassays. A well-known antibody against the FLAG peptide, clone M2, was used as a model system and the results were compared with other methods. This approach could be used in any case where a competitive assay is available or can be developed. The determination of an affinity constant should belong to the crucial parameters in any quality control of antibody-related products and assays and should be mandatory in papers using immunochemical protocols. N2 - Die Affinitätskonstante, auch bekannt als Gleichgewichtskonstante, Bindungskonstante, Gleichgewichtsassoziationskonstante oder der reziproke Wert, die Gleichgewichtsdissoziationskonstante (Kd), kann als eine der wichtigsten Eigenschaften für jedes Antikörper-Antigen-Paar angesehen werden. Zur Bestimmung dieses Wertes wurden zahlreiche Methoden auf der Grundlage verschiedener Technologien vorgeschlagen und verwendet. Da jedoch eine sehr große Anzahl von Veröffentlichungen und kommerziellen Datenblätter diese Information nicht enthalten, scheint es erhebliche Hindernisse bei der Durchführung solcher Messungen zu geben. In anderen Fällen, in denen solche Daten angegeben werden, haben sich die Ergebnisse häufig als unzuverlässig erwiesen. Diese Situation könnte darauf hindeuten, dass die meisten der heute verfügbaren Technologien ein hohes Maß an Fachwissen und Aufwand erfordern, das in vielen Labors nicht vorhanden zu sein scheint. In diesem Beitrag stellen wir einen einfachen Ansatz vor, der auf der Standard-Immunoassay-Technologie basiert und einfach und schnell durchführbar ist. Er beruht auf dem Effekt, dass sich der molare IC50 bei unendlich kleinen Reagenz-Konzentrationen dem Kd-Wert annähert. Eine zweidimensionale Verdünnung der Reagenzien führt zu einer asymptotischen Konvergenz zu Kd. Der Ansatz hat eine gewisse Ähnlichkeit mit der bekannten Checkerboard-Titration, die zur Optimierung von Immunoassays verwendet wird. Ein bekannter Antikörper gegen das FLAG-Peptid, Klon M2, wurde als Modellsystem verwendet, und die Ergebnisse wurden mit anderen Methoden verglichen. Dieser Ansatz kann überall dort angewendet werden, wo ein kompetitiver Assay verfügbar ist oder entwickelt werden kann. Die Bestimmung einer Affinitätskonstante sollte zu den entscheidenden Parametern bei der Qualitätskontrolle von Antikörperprodukten und -assays gehören und in Arbeiten, die immunchemische Protokolle verwenden, obligatorisch sein. KW - ELISA KW - Competitive immunoassay KW - IC50 KW - Test midpoint KW - Point of inflection KW - Equilibrium constant KW - Dissociation constant KW - Binding strength KW - Antibody antigen complex KW - Bio-interaction KW - SPR KW - Surface-plasmon resonance KW - FLAG peptide KW - Clone M2 KW - Antibody quality PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605607 DO - https://doi.org/10.3390/mps7030049 SN - 2409-9279 VL - 7 IS - 3 SP - 1 EP - 11 PB - MDPI CY - Basel AN - OPUS4-60560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Béalu, Zoé A1 - Walther, Johanna A1 - Abusafia, Attaallah A1 - Altmann, Korinna A1 - Meurer, Maren A1 - Gretzschel, Oliver A1 - Schäfer, Michael A1 - Steinmetz, Heidrun T1 - Removal of Organic Micropollutants and Microplastics via Ozonation Followed by Granular Activated Carbon Filtration N2 - Discharge from Wastewater Treatment Plants (WWTPs) can result in the emission of organic micropollutants (OMPs) and microplastics (MPs) into the aquatic environment. To prevent this harmful release, a pilot plant consisting of an ozonation followed by a granular activated carbon (GAC) filter was operated at a WWTP in Germany, and its side-effects on the concentrations of nitrogen (N) and phosphorous (P) compounds were measured. Over 80% of OMPs and transformation products were removed during the operating time (around 6000 bed volumes) no matter the ozone dose (from around 0.1 to 0.5 mgO3/mgDOC), except for Diatrizoic acid, whose breakthrough appeared at 3500 BV. Formation of the oxidation by-product, NDMA, increased with higher ozone doses, but the concentration remained below 100 ng/L. Bromate was formed at a higher ozone dose (0.4 mgO3/mgDOC) but at a low concentration—below 10 µg/L. The MP particles detected in the inflow (PE, SBR, PP, and PS) were effectively eliminated to a high degree, with a removal rate of at least 92%. Carbon parameters (COD, DOC, and SAC254) were removed further by the pilot plant, but to different extents. As expected, nitrate was formed during ozonation, while nitrite’s concentration decreased. Further, nitrite decreased and nitrate increased within the GAC filter, while ammonium was eliminated by at least 90%. Total P concentration decreased after the pilot, but the concentration of PO4-P increased. KW - Microplastics KW - TED-GC/MS KW - Granular Activated Carbon Filtration KW - Removal of Organic Micropollutants KW - Wastewater treatment plant PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615209 DO - https://doi.org/10.3390/environments11110241 VL - 11 IS - 11 SP - 1 EP - 38 PB - MDPI AG AN - OPUS4-61520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fadda, Marta A1 - Sacco, Alessio A1 - Altmann, Korinna A1 - Ciornii, Dmitri A1 - Milczewski, Frank A1 - Bañares, Miguel A. A1 - Portela, Raquel A1 - Giovannozzi, Andrea Mario A1 - Rossi, Andrea Mario T1 - Tracking nanoplastics in drinking water: a new frontier with the combination of dielectrophoresis and Raman spectroscopy N2 - Detection of micro- (MPs) and nanoplastics (NPs) in food and environmental matrices has been gaining relevance due to their potential toxicological effects on human health. While MPs have been detected in a wide range of complex matrices, suitable methods for the characterization and chemical identification of NPs are still lacking, primarily due to significant methodological challenges associated with their nano-specific physiochemical properties, including size distribution (1 nm – 1 µm), dynamic surface chemical changes, and carbon-based composition, which complicate their detection compared to engineered nanomaterials. To overcome the traditional limitations of spectroscopic techniques in terms of spatial resolution and sensitivity at the sub-micrometer level, a novel label-free methodology is presented for specifically identifying the chemical composition of NPs directly in suspension by combining Raman spectroscopy with dielectrophoresis (DEP). Using a custom-built device, small volumes of NPs are injected into a dielectrophoretic cell and locally trapped by DEP forces to fill the Raman confocal volume, facilitating their detection and identification, and providing high signal-to-noise ratio Raman spectra for more reliable analysis. This approach was successfully applied to both Milli-Q water and a commercial brand of drinking water, enabling the rapid identification of various types of NPs with different sizes and polymer compositions at concentrations as low as 20 µg/mL. These included certified reference polystyrene beads ranging from 800 to 60 nm in diameter, as well as polydisperse NPs, more representative of real samples in terms of size distribution and polymer type, such as polyethylene (450 nm), polypropylene (180 nm), and polyethylene terephthalate (100 nm). Moreover, the chemical fingerprint of each NPs was thoroughly investigated and compared with the corresponding bulk polymers, highlighting possible changes in the Raman bands due to surface oxidation or nanometer-scale effect. Therefore, this innovative method can be considered a valuable approach for addressing gaps in the detection and identification of NPs, as well as for monitoring their dynamic phisiochemical changes in real matrices. KW - Nanoplastics KW - Water contaminants KW - Raman microspectroscopy KW - Dielectrophoresis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633658 DO - https://doi.org/10.1186/s43591-025-00131-y SN - 2662-4966 VL - 5 IS - 1 SP - 1 EP - 11 PB - Springer Science and Business Media LLC AN - OPUS4-63365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan A1 - Wachtendorf, Volker A1 - Fengler, Petra A1 - Altmann, Korinna T1 - Interlaboratory Comparison Reveals State of the Art in Microplastic Detection and Quantification Methods N2 - In this study, we investigate the current accuracy of widely used microplastic (MP) detection methods through an interlaboratory comparison (ILC) involving ISO-approved techniques. The ILC was organized under the prestandardization platform of VAMAS (Versailles Project on Advanced Materials and Standards) and gathered a large number (84) of analytical laboratories across the globe. The aim of this ILC was (i) to test and to compare two thermo-analytical and three spectroscopical methods with respect to their suitability to identify and quantify microplastics in a water-soluble matrix and (ii) to test the suitability of the microplastic test materials to be used in ILCs. Two reference materials (RMs), polyethylene terephthalate (PET) and polyethylene (PE) as powders with rough size ranges between 10 and 200 μm, were used to press tablets for the ILC. The following parameters had to be assessed: polymer identity, mass fraction, particle number concentration, and particle size distribution. The reproducibility, SR, in thermo-analytical experiments ranged from 62%−117% (for PE) and 45.9%−62% (for PET). In spectroscopical experiments, the SR varied between 121% and 129% (for PE) and 64% and 70% (for PET). Tablet dissolution turned out to be a very challenging step and should be optimized. Based on the knowledge gained, development of guidance for improved tablet filtration is in progress. Further, in this study, we discuss the main sources of uncertainties that need to be considered and minimized for preparation of standardized protocols for future measurements with higher accuracy. KW - Microplastics KW - Interlaboratory comparison KW - PlasticsFatE KW - PET KW - PE KW - Reference materials KW - VAMAS KW - Thermo-analytical methods KW - Spectroscopical methods PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630462 DO - https://doi.org/10.1021/acs.analchem.4c05403 SN - 1520-6882 VL - 97 SP - 8719 EP - 8728 PB - ACS Publications AN - OPUS4-63046 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartczak, Dorota A1 - Sikora, Aneta A1 - Goenaga-Infante, Heidi A1 - Altmann, Korinna A1 - Drexel, Roland A1 - Meier, Florian A1 - Alasonati, Enrica A1 - Lelong, Marc A1 - Cado, Florence A1 - Chivas-Joly, Carine A1 - Fadda, Marta A1 - Sacco, Alessio A1 - Rossi, Andrea Mario A1 - Pröfrock, Daniel A1 - Wippermann, Dominik A1 - Barbero, Francesco A1 - Fenoglio, Ivana A1 - Booth, Andy M. A1 - Sørensen, Lisbet A1 - Igartua, Amaia A1 - Wouters, Charlotte A1 - Mast, Jan A1 - Barbaresi, Marta A1 - Rossi, Francesca A1 - Piergiovanni, Maurizio A1 - Mattarozzi, Monica A1 - Careri, Maria A1 - Caebergs, Thierry A1 - Piette, Anne-Sophie A1 - Parot, Jeremie A1 - Giovannozzi, Andrea Mario T1 - Multiparameter characterisation of a nano-polypropylene representative test material with fractionation, light scattering, high-resolution microscopy, spectroscopy, and spectrometry methods N2 - Reference and quality control materials with comparable physicochemical properties to nanoplastic contaminants present in environmental and food nanoplastics are currently lacking. Here we report a nanoplastic polypropylene material prepared using a top-down approach involving mechanical fragmentation of larger plastics. The material was found to be homogeneous and stable in suspension and has been characterised for average particle size, size distribution range, particle number concentration, polypropylene mass fraction and inorganic impurity Content using a wide range of analytical methods, including AF4, cFFF, PTA, (MA)DLS, MALS, SEM, AFM, TEM, STEM, EDS,Raman, ICP-MS and pyGC-MS. The material was found to have a broad size distribution, ranging from 50 nm to over 200 nm, with the average particle size value dependent on the technique used to determine it. Particle number concentration ranged from 1.7–2.4 × 1010 g−1 , according to PTA. Spectroscopy techniques confirmed that the material was polypropylene, with evidence of aging due to an increased level of oxidation. The measured mass fraction was found to depend on the marker used and ranged between 3 and 5 μg g−1 . Inorganic impurities such as Si, Al, Mg, K, Na, S, Fe, Cl and Ca were also identified at ng g−1 levels. Comparability and complementarity across the measurement methods and techniques is also discussed. KW - Polypropylene KW - Nanoplastics KW - Analytics KW - Reference material KW - Scattering methods PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654680 DO - https://doi.org/10.1039/D5EN00917K SN - 2051-8153 SP - 1 EP - 15 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittner, Maria A1 - Coesfeld, Bianca A1 - Schlau, Sven A1 - Werischak, Thomas A1 - Altmann, Korinna A1 - Kalbe, Ute T1 - Simultaneous sampling for microplastics and environmental contaminants from artificial turf: development of a new integrated microplastics eluate lysimeter N2 - To get a better understanding of potentially harmful contaminant emissions from soils or materials into the environment, politics demand practical and holistic sampling concepts for environmental samples such as leachates containing polycyclic aromatic hydrocarbons (PAH) or heavy metals, and hazardous particulate matter like microplastics (MP). Of particular concern are MP emissions from artificial turf sports pitches. So far, there has been only very limited data on MP mass emissions from artificial turf potentially posing a risk to the groundwater and no sampling device that allowed simultaneous sampling for dissolved and particulate contaminants. In this study, a novel integrative microplastics eluate lysimeter was developed to determine contaminant emissions from three artificial turf systems at different ageing states (fabric-new, artificially aged, real-time aged). For the accelerated ageing, all environmental simulation parameters were based on Central German conditions and simulated outdoor stress during the turf service lifespan of 15 years. MP masses from eluates were analysed using thermal extraction desorption-gas chromatography/mass spectrometry, PAH concentrations using gas chromatography/mass spectrometry and heavy metals using inductively coupled plasma-optical emission spectroscopy. Results showed that no PAH or heavy metal concentrations from the seepage water were above German legal limits for alternative granular construction materials considering soil and groundwater protection. Furthermore, it was found that only minimal MP emissions were released from new turf systems into the seepage water (< 1 mg/m2). Ageing of the artificial turf increased MP formation, especially from rubber infill and grass fibres, which are then carried into the seepage water. The highest total MP emissions over a simulated turf lifespan of 15 years were detected in two real-time aged turf systems ranging from 136.4–252.5 mg/m2. Considerably less total MP emissions were detected in accelerated aged artificial turf systems, one of which contained a synthetic rubber infill (5.4–8.0 mg/m2) and one without rubber infill (0.2–5.3 mg/m2). In summary, it was demonstrated that the newly developed MEL generated reliable and reproducible data and has thus proven itself as an integrated, straightforward and automated sampling device for simultaneous monitoring of particulate and dissolved pollutant emissions from simple soil matrices. KW - Lysimeter KW - Microplastics KW - Artificial turf KW - Thermal extraction desorption-gas chromatography/mass spectrometry KW - TED-GC/MS KW - Polycyclic aromatic hydrocarbons KW - PAH KW - Heavy metals KW - Soil samples PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645301 DO - https://doi.org/10.1186/s12302-025-01235-1 SN - 2190-4715 VL - 37 IS - 1 SP - 1 EP - 15 PB - Springer Open AN - OPUS4-64530 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herzel, Hannes A1 - Grevel, K.-D. A1 - Emmerling, Franziska A1 - Dachs, E. A1 - Benisek, A. A1 - Adam, Christian A1 - Majzlan, J. T1 - Thermodynamic properties of calcium alkali phosphates Ca(Na,K)PO4 N2 - Calcium alkali phosphates Ca(Na,K)PO4 are main constituents of bioceramics and thermochemically produced phosphorus fertilizers because of their bioavailability. Sparse thermodynamic data are available for the endmembers CaNaPO4 and CaKPO4. In this work, the missing data were determined for the low-temperature phase modifications of the endmembers CaNaPO4 and CaKPO4 and three intermediate Ca(Na,K)PO4 compositions. Standard enthalpy of formation ranges from - 2018.3 ± 2.2 kJ mol-1 to - 2030.5 ± 2.1 kJ mol-1 and standard entropy from 137.2 ± 1.0 J mol-1 K-1 to 148.6 ± 1.0 J mol-1 K-1 from sodium endmember b-CaNaPO4 to potassium endmember b0-CaKPO4. Thermodynamic functions are calculated up to 1400 K for endmembers and the sodium-rich intermediate phase b-Ca(Na0.93K0.07)PO4. Functions above 640 K are extrapolated because of the phase transition from low- to high-temperature phase. Impurities in the synthesized intermediate phases c-Ca(Na0.4K0.6)PO4 and c-Ca Na0.35K0.65)PO4 and one additional phase transition around 500 K impeded the determination of high-temperature thermodynamic functions. In general, data for phase transition temperatures agree with the previously reported phase diagrams. KW - Formation enthalpy KW - Heat capacity KW - Phase transformation KW - Bioceramics KW - Phosphorus fertilizer KW - Entropy PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507640 DO - https://doi.org/10.1007/s10853-020-04615-5 VL - 55 SP - 8477 EP - 8490 PB - Springer AN - OPUS4-50764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -