TY - CONF A1 - Miclea, P.-T. T1 - Micro- and nanoplastic particle number and mass-based analysis on a plastic-free size-selective two stage Si membrane filtration cascade N2 - The poster presents a Si wafer filter development as two stage cascade and the adapter for microplastics filtration. T2 - SETAC Europe 2023 CY - Dublin, Ireland DA - 30.04.2023 KW - Microplastics KW - Filtration KW - TED-GC/MS KW - Polymer 3R KW - Cascade filtration PY - 2023 AN - OPUS4-57461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miclea, P.-T. T1 - Real-life airborne micro- and nano-plastic particles and fibres on a porous membrane filter system from a textile factory suitable for both: vibrational and mass spectrometry N2 - The poster presents an application of Si wafer filter system on indoor air sampling. A textile factory producing PP fibres was sampled. T2 - SETAC Europe 2023 CY - Dublin, Ireland DA - 30.04.2023 KW - Microplastics KW - Polymer 3R KW - Textile fibres KW - Si wafer filter KW - Microplastics sampling PY - 2023 AN - OPUS4-57462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Insights into materials with hard x-rays: capabilities of the bamline N2 - This contribution provides an overview of the BAMline synchrotron radiation beamline, which specializes in hard X-ray spectroscopy techniques for materials research. The BAMline offers X-ray absorption spectroscopy (XAS), x-ray fluorescence spectroscopy (XRF), and tomography to study materials' electronic structure, chemical composition, and structure. Key capabilities include standard and dispersive XAS for electronic structure, micro-XRF for elemental mapping, coded aperture imaging, and depth-resolved grazing exit XAS. The BAMline enables in situ characterization during materials synthesis and functions for energy, catalysis, corrosion, biology, and cultural heritage applications. Ongoing developments like the implementation of machine learning techniques for experiment optimization and data analysis will be discussed. For instance, Bayesian optimization is being used to improve beamline alignment and scanning. An outlook to the future, where the BAMline will continue pioneering dynamic and multi-scale characterization, aided by advanced data science methods, to provide unique insights into materials research, will be given. T2 - μ-XRF at Elettra 2.0: challenges and opportunities CY - Trieste, Italy DA - 11.09.2023 KW - Synchrotron KW - XRF KW - XANES KW - Bayes PY - 2023 AN - OPUS4-58607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rossi, A T1 - Lactose Tablets as Suitable Microplastics Reference Material to Support Validation Studies and Quality Control N2 - One of the main challenges in validating microplastics detection methods is the lack of suitable reference materials that accurately reflect the properties of interest. To bridge this gap, the EU-funded PlasticTrace project has developed water-soluble tablets containing precisely defined amounts of polyethylene terephthalate (PET) particles. Each tablet includes a specific mass (0.2, 18.5, or 400 µg) and particle count (151 or 1764, measured via Raman spectroscopy). Production follows a rigorous solid-phase dilution process, ensuring high reproducibility and quality control. The PET particles used in these tablets have an average size of approximately 40 µm, with a range between 10 and 200 µm, and an irregular, stone-like shape. All measurements align with ISO/TC 147/SC 2 standardization efforts and adhere to ISO/DIS 16094-2 and ISO/DIS 16094-3. To assess tablet homogeneity, the most widely accepted microplastics detection techniques, i.e. µ-FTIR, µ-Raman, Py-GC/MS, and TED-GC/MS, were applied. Different batches were produced, each containing varying particle numbers and masses, reaching the detection limits of the methods used. The results demonstrated excellent consistency between tablets, successfully passing homogeneity tests. Furthermore, no significant changes were observed in the tablets' composition or stability after six months of storage. This innovative reference material represents an important advancement in microplastics analysis, supporting laboratories in meeting EU Commission requirements for the monitoring of microplastics in drinking water and wastewater with greater accuracy and reliability. The production process can be transferred for other plastic particles is this size range. T2 - BERM 16 CY - Halifax, Canada DA - 01.06.2025 KW - Microplastics KW - TED-GC/MS KW - Reference materials KW - Raman microscopy PY - 2025 AN - OPUS4-63403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fernández-González, V. T1 - Innovations in Microplastic Measurement: A Pyrolysis Approach for a Polyethylene Terephthalate Reference Material N2 - In the framework of the PlasticTrace project, in which a reference material for PET microplastics will be proposed, a method using pyrolysis and gas chromatography coupled with mass spectrometry detection (Py-GC-MS) is developed to quantify the mass of PET microplastics (10-100 µm) in tablets at two different concentration levels. The overall aim of this project is to develop international metrological capacity that enables the traceable measurement and characterization of SMPs and NPs in environmental and food samples and the production of suitable reference materials, according to the metrological requirements (https://plastictrace.eu/). The proposed method consists of dissolving the tablet containing the PET microplastics in milli-Q water and filtering the solution using a glass microfiber membrane 13 mm filter size, 1.6 µm pore size. After filtering and several washes to ensure complete dissolution of the tablet and recovery of all PET microplastics, the filter is removed, folded, and placed in a capsule of the pyrolyzer for direct Py-GC/MS analysis. Two main markers were selected for PET quantification: vinyl benzoate and benzoic acid, with consistent concentrations found for both at high PET concentrations (≈400 µg) (24% RSD, n=17), but interferences with the matrix and vinyl benzoate were found at low concentrations (≈17 µg PET), with only benzoic acid being valid as a marker in this case (22% RSD, n=10). As an alternative to the quantification of PET microplastics in tablets at low concentrations, derivatization is proposed, for which tetramethylammonium hydroxide solution (TMAH) is added directly into the pyrolysis cap. The PET marker in this case is dimethyl terephthalate, with which good results have also been found (19.6% RSD, n=10 ). The proposed method is robust, simple, with high automation and very little sample handling and treatment, and allows the analysis of PET microplastics (>10 µm) in tablets with excellent accuracy and precision even at very low concentrations. T2 - SETAC Europe 2025 CY - Vienna, Austria DA - 11.05.2025 KW - Microplastics KW - Nanoplastics KW - GC/MS PY - 2025 AN - OPUS4-63383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Booth, A. T1 - Production of a 1-10 μm polypropylene reference material for development of analytical methods N2 - The poster is about the preparation of microplastics in the size range of 1-10 µm. These size range of particles can be inhalded and therefore be toxic for humans. The preparation is done by comminution of PP pellets and sieving. Characterisation occured for size with laser diffraction, for type with FTIR and for shape with SEM. T2 - SETAC Europe 2025 CY - Vienna, Austria DA - 11.05.2025 KW - Microplastics KW - Reference materials PY - 2025 AN - OPUS4-63367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miclea, P.-T. T1 - Novel laser pre-structured silicon filters for microplastics analysis N2 - This research presents a novel laser-assisted approach to silicon filter fabrication, offering an effective alternative to traditional photolithographic processes. By integrating selective femtosecond laser irradiation with photoelectrochemical etching, we achieved precisely controlled pore geometries, overcoming common challenges in filter production for microplastic and nanoscale filtration suitable for microplastic number and mass analysis. T2 - SETAC Europe 2025 CY - Vienna, Austria DA - 11.05.2025 KW - Microplastics KW - Nanoplastics KW - Raman microspectroscopy PY - 2025 AN - OPUS4-63384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Putzu, Mara T1 - Optimization of production process for microplastics reference materials N2 - Microplastics (MP) are defined as plastic particles mainly consisting of polymers in the size range of 1 to 1000 µm. They can be found in a wide range of environmental matrices but also in food products, indicating a potential risk on humans and environment. Plastic debris in the environment or food chain are extremely complex in terms of size, concentration, polymer type, levels of physiochemical degradation and undefined morphologies which makes their isolation and detection in complex matrices challenging. Analytical detection methods and techniques to identify and quantify microplastics in environmental and food matrices are numerous but validated and standardized methods are currently lacking. To close this research gap, reference materials (RMs) and representative sample preparation approaches are urgently needed. Homogeneity and stability are two crucial characteristics for the certification process of the reference materials. For this purpose, we aim to present ways to prepare reference materials containing very low masses of close-to reality plastic particles with broad size distribution (10-100 µm) that are homogeneously distributed in tablet-to-tablet variation and stable over time. Our work is based on the ISO Guide 30:2015 and ISO Guide 35:2017 to fulfil the criteria set in future standards ISO/DIS 16094-2 and ISO/DIS 16094-3. The property of interest will be the mass detected by thermogravimetric analysis (TGA). Furthermore, informative values will be achieved by mass-based technique TED-GC/MS and spectroscopic microscopy techniques, such as µ-FTIR spectroscopy and µ-Raman. T2 - SETAC Europe 2025 CY - Vienna, Austria DA - 11.05.2025 KW - Microplastics KW - Reference materials KW - TED-GC/MS PY - 2025 AN - OPUS4-63386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Holistic Experimentation in the HExX-Lab N2 - Through bottom-up, comprehensive digitalisation of all aspects of an experiment, the HEX-lab improves the trustworthiness (traceability, reproducibility, quality) of scientific findings. The five main parts that make up a materials science experiment, i.e. Sample preparation, Measurements, Processing, Analysis, and Interpretation, each have been addressed in thorough and unique ways in this lab, building up a foundation for a wide range of materials science collaborations. Improvements span the spectrum. Hardware developments include new sample environments and stages, such as grazing incidence motion towers, electrochemistry cells and flow-through holders, electronic components such as safety interlocks and multipurpose I/O controllers, and liquid handling systems such as coolant flow cross-over systems. Software developments include: 1) a new comprehensive control system operating on both the RoWaN as well as the MOUSE allowing for full Python control and sequencing of all experimentation, 2) Automated scripts for instrument optimization, sample alignments and measurements, 3) revamped data pipelines and analysis software, standalone or launched as part of operations sequencing dashboards on servers, and 4) meticulously structured archival datafiles, fully documenting sample preparation, measurements, processing and analyses. These allow for holistic databases and dashboards to be constructed to investigate the links between synthesis parameters and resulting morphology. This poster will highlight some of the tools and techniques developed and available in the HEX-lab over the years, from sample environments to overarching experiment and data organisation structures. T2 - Materials Science Core Facility Synergy Forum 2025 CY - Bremen, Germany DA - 26.02.2025 KW - Digitalization KW - Holistic experiments KW - Traceability KW - Data provenance PY - 2025 AN - OPUS4-62675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulow, Anicó A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Hampel, S. A1 - Fittschen, UEA A1 - Streli, C. A1 - Radtke, Martin T1 - Reconstruction for coded aperture full-field x-ray fluorescence imaging N2 - X-ray fluorescence imaging is a well-established tool in materials characterization. In this work, we present the adaption of coded aperture imaging to full-field X-ray fluorescence imaging at the synchrotron. Coded aperture imaging has its origins in astrophysics, and has several advantages: Coded apertures are relatively easy to fabricate, achromatic, allow a high photon throughput, and high angular acceptance. Coded aperture imaging is a two-step-process, consisting of the measurement process and a reconstruction step. Different programs have been written, for the raytracing/forward projection and the reconstruction. Experiments with coded aperture in combination with a Color X-ray Camera and an energy-dispersive area detector, have been conducted at the BAMline. Measured samples were successfully reconstructed, and gave a 9.1-fold increase in count rate compared to a polycapillary optic. KW - Synchrotron KW - BAMline KW - Coded Aperture PY - 2022 SN - 1097-0002 VL - 65 SP - 57 EP - 70 PB - Cambridge University Press CY - Cambridge AN - OPUS4-56350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Altmann, Korinna T1 - Reference material BAM-P206 polyethylene terephthalate (powder) N2 - This report contains detailed information on the preparation of the reference material as well as on homogeneity and stability investigations of the property of interest, the equivalent particle diameter, and on the analytical methods to determine the additional properties. The values for particle size distribution are based on the results from laser diffraction measurements of 3 different devices with at least 3 replicate measurements of 4 randomly chosen units of the reference material P206. KW - Microplastic KW - Reference material KW - PET PY - 2023 DO - https://doi.org/10.26272/opus4-59778 SP - 1 EP - 23 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-59778 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miclea, Paul T1 - Microanalysis of Airborne Nano/Microplastic Particles in an Textile Industrial Environment N2 - Micro- and nanoplastics (MNPs) are emerging global contaminants, present in air, soil, and water. The textile industry is potentially a major contributor, releasing synthetic particles like polyamide, polyester, and acrylic during production. This study assessed MNP levels outside and inside a textile-processing facility using online air samplers with silicon (Si) and quartz filters. Real-time particle counts (PM0.3–PM10) were obtained via a laser detector. Si filters (9 mm, 10/1 µm pores) and quartz filters (25 mm, 1.2 µm pores, pre-calcined at 800°C) were used for sampling. Custom holders allowed selective sampling for PM10 and PM1 on Si filters. Sampling conditions included a 3-hour collection at 2 L/min (GilAir Plus pump) starting at 7:00 AM (T1) and 2:00 PM (T2), with intermittent ventilation, 23.3 °C average temperature, and 52.5% humidity. Particle weights collected (µg) were: quartz – 4.9E-05 (T1), 5.1E-05 (T2); Si – 3.2E-05 (T1), 5E-06 (T2). Outside particle counts ranged from 3,584 (T1) to 15,165 (T2); inside: 9,901 (T1) to 12,921 (T2). Maximum indoor PM10 and PM0.3 levels were 72/m³ and 71,979/m³, respectively. Particles were analyzed using electron microscopy and µRaman spectroscopy, confirming high concentrations of irregularly shaped PP-based particles (1–5 µm). T2 - 12th TEXTEH CY - Bucharest, Romania DA - 23.10.2025 KW - Microplastics KW - Airborne particles KW - Raman microspectroscopy PY - 2025 AN - OPUS4-64485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drexel, R. T1 - Nano-sized Polypropylene as a Promising Candidate Reference Material: Preparation, Characterization and Stability in Complex Matrices N2 - The lack of nanoplastic (NPs) reference materials capable of mimicking real-world scenarios is currently hampering the development of validated extraction techniques from complex matrices (e.g. soils, sediments, biota), the development of analytical approaches for robust identification and quantification, and the ability to use environmentally relevant test materials in (eco)toxicity testing and hazard assessment [1]. The large body of available data suggests that larger microplastics (MPs) in the natural environment are irregular shaped, partially degraded (chemically and physically), a continuum of sizes, shapes and densities, represent a wide range of polymer types, and acts as a reservoir for thousands of plastic chemicals. Although NPs have been described as being neither MPs nor engineered nanoparticles [2], and while direct measurement data of true NP in the environment remain elusive, they are expected to be as equally diverse as MPs [3]. Here, we present a strategy towards the development of a potential NP reference material based on nano-sized polyproplyene particles (nanoPP) developed within the EURAMET-funded PlasticTrace project (https://plastictrace.eu/). The strategy includes the preparation, the physicochemical characterization and the stability assessment of nanoPP in suspension both in its pristine state, but also when spiked into food (mineral water and milk) and environmental matrices (suspended particulate matter collected from the river Elbe ). Collected experimental data suggests nanoPP to be a promising candidate for a NP reference material. T2 - SETAC Europe 2025 CY - Vienna, Austria DA - 11.05.2025 KW - Nanoplastics KW - Reference materials PY - 2025 AN - OPUS4-63382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Validation of microplastics detection methods and proficiency testing: Suitable microplastic reference materials for interlaboratory comparison N2 - The talk summarizes challenges in microplastic analysis. It shows the preparation of microplastic reference materials as well as the testing on homogeneity and stability. The reference material is used in an international laboratory comparison to compare different detection methods used for microplastic analysis. The methods used were µ-IR (FTIR+LDIR) for number-based methods and TED-GC/MS and Py-GC/MS for mass-based methods. The ILC was done under the umbrella of VAMAS TWA 45. Results of the participants are presented. T2 - BAM Akademie CY - Online meeting DA - 16.05.2024 KW - Microplastics KW - Reference materials KW - ILC KW - Microplastics detection KW - TED-GC/MS KW - Polymer 3R PY - 2024 AN - OPUS4-60085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Mikroplastik Detektion mit Thermoanalytischen Methoden: Analytik, Referenzmaterial, Ringversuche N2 - Ich dem Vortrag geht es um die Vorstellung von thermoanalytischen Methoden für die Mikroplastik-Detektion. Verschiedene Kopplungsmöglichkeiten werden gezeigt und die Funktionsweise der TED-GC/MS wird erklärt. Im zweiten Teil werden Referenzmaterialien für die Mikroplastik-Analytik diskutiert. PET -Tabletten des PlasticTrace Projektes werden vorgestellt. Am Ende wird der VAMAS Ringversuch zur Mikroplastik-Detektion gezeigt. T2 - Plastik, Mikroplastik, Nanopartikel, PFAS und Verunreinigungen (Agilent Workshop) CY - Hamburg, Germany DA - 28.05.2024 KW - Mikroplastik KW - TED-GC/MS KW - Polymer 3R KW - Ringversuche KW - Referenzmaterial PY - 2024 AN - OPUS4-60155 LA - deu 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-Analytik N2 - Im Vortrag wir eine Methode zur Analyse von Mikroplastik in Böden dargestellt. Es geht dabei um die Probenvorbereitung und Detektion. T2 - Fachgespräch "Plastik in Böden" CY - Online meeting DA - 28.03.2022 KW - Mikroplastik KW - TED-GC/MS KW - Mikroplastik-Analytik KW - Methodenentwicklung Böden PY - 2022 AN - OPUS4-54646 LA - deu 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 - CONF A1 - Drago, Claudia T1 - Rapid sample preparation to detect microplastics in baby milk powder N2 - Microplastics, ubiquitous as it is, could be released into food during production chain, through packaging and by consumer´s use. To determinate human exposure to microplastics is crucial to monitor microplastics in food matrices. The current absence of standard sample preparation procedures to identify and quantify different microplastics according to number and mass have generate time-consuming protocols and lack of comparability among different analytical methods, laboratories and time scales. Monitoring microplastics in complex matrices as food, and in particular in baby milk powder, requires an accurate approach that need to be validate, to ensure the comparability of results. Bottled drinking water or surface waters, for example, can be measured with mass-based methods (TED-GC/MS or Py-GC/MS) directly after filtration. Baby milk powder, instead is more challenging, due to the proteins and fatty acid that clog the filters and contaminate the measuring devices with heavy carry over. In this study, we characterize the baby milk powder by thermogravimetric analysis (TGA) and we tested different treatments for matrix reduction: water, H2O2, citric acids. In particular, the use of citric acid was tested for protein reduction before filtration. Our hypothesis was that citric acid will induce the precipitation of proteins and amino acids, leading to a strong matrix reduction. In fact, this sample pre treatment, allowed us to use a higher intake, necessary for representative quantification. Finally, the milk powder was spiked with reference material tablets containing polyethylene terephthalate (PET). The PET was not degraded by the citric acid and high recovery rate was achieved by TED-GC/MS and Py-GC/MS methods. Considering the simplicity and accessibility of this sample preparation and its robust results, this procedure could be easily proposed as a simple sample preparation approach to monitor microplastics by mass-based methods. T2 - MICRO 2024 CY - Arrecife, Spain DA - 23.09.2024 KW - Microplastics KW - Milk KW - Polymer 3R KW - TED-GC/MS PY - 2024 AN - OPUS4-61273 LA - eng 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 - 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 - Altmann, Korinna T1 - Mikroplastik – Ein Problem für die Menschheit? N2 - Mikroplastik findet sich in Ozeanen, Seen, Flüssen und Bächen. Es kann in unserem Boden, in der Luft und sogar in Organismen nachgewiesen werden. Jedes Jahr werden weltweit Millionen Tonnen freigesetzt. Doch wo und wie landet Mikroplastik in der Umwelt? Und wie können wir diese winzigen Partikel nachweisen? T2 - Berlin Science Week CY - Berlin, Germany DA - 01.11.2021 KW - Mikroplastik KW - TED-GC/MS PY - 2021 AN - OPUS4-53734 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Microplastics at BAM: TED-GC/MS and reference materials N2 - Thsi talk aims to present the activities of microplastic analysis at BAM according to TED-GC/MS and reference materials developement. T2 - Webinar BAM / University of Birmingham CY - Online meeting DA - 15.06.2021 KW - Microplastic KW - TED-GC/MS KW - Reference materials PY - 2021 AN - OPUS4-53738 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Smales, G. J. T1 - DACHS-MOFs Database for Automation, Characterisation, and Holistic Synthesis N2 - The DACHS (Database for Automation, Characterization and Holistic Synthesis) project aims to create completely traceable experimental data, covering syntheses, measurements, analyses, and interpretations. DACHS MOFs focuses on the synthesis and characterisation of metal-organic frameworks (MOFs), across multiple, automation-assisted experimental series (AutoMOFs), with the overall goal of producing reproducible MOF syntheses. So far > 1200 MOF samples have been synthesised, with SAXS/WAXS data currently being collected on all samples. All results, including those from “failed” syntheses, are included in the database, as results are results and should be considered agnostic to any positive ornegative interpretations. DACHS MOFs represents the initial trial of the DACHS project, serving as a comprehensive resource for researchers aiming to optimize the synthesis and characterization of MOFs. T2 - XIX International Small Angle Scattering Conference CY - Taipei, Taiwan DA - 04.11.2024 KW - Lab automation KW - Synthesis KW - Metal organic frameworks KW - Zif-8 KW - Databases KW - Synthesis data PY - 2024 AN - OPUS4-61626 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 - 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 - 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 - GEN A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard T1 - DACHS/MOFs/AutoMOFs_1/Synthesis N2 - The DACHS (Database for Automation, Characterization and Holistic Synthesis) project aims to create completely traceable experimental data, covering syntheses, measurements, analyses, and interpretations. DACHS_MOFs focuses on the synthesis and characterisation of metal-organic frameworks, across multiple, automation-assisted experimental series (AutoMOFs), with the overall goal of producing reproducible MOF samples through tracking of the synthesis parameters. DACHS_MOFs is simultaneously used to test the DACHS principles. This upload contain synthesis data from AutoMOFs_1 in HDF5 format (.h5). Each .h5 file contains detailed information on the chemical, experimenal, and synthesis parameters used during the synthesis of a single AutoMOF sample. KW - Synthesis KW - Automation KW - Traceability KW - Procedure PY - 2024 DO - https://doi.org/10.5281/zenodo.11236031 PB - Zenodo CY - Geneva AN - OPUS4-60243 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 - 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 - 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 - 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 - 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 - 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 - 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 - CONF A1 - Altmann, Korinna T1 - Reference material candidates for microplastic analysis N2 - Every day, there are new headlines in the media about microplastics (1-1000 µm, ISO/TR 21960:2020) and nanoplastics (< 1 µm, ISO/TR 21960:2020) findings all over the planet with high variations in particle number and mass. The challenges in analytics are very complex, e.g. representative sampling, non-destructive sample preparation with concentrated particles and homogeneous distribution and true detection. All together lead to lacks in harmonization and results, which are hardly comparable. On the other hand, monitoring of microplastics is mandatory in the future strictly regulated by the EU commission in the Drinking water and Wastewater Framework Directive. One step to accurate and precise results will be the development of suitable reference materials mimicking particles in the environment. BAM developed test materials, which are produced by mixing a small portion of microplastic particles with a water-soluble matrix. After solid phase dilution and homogenisation small portions are pressed into tablets and bottled in glass vials (Figure 1). These tablets are well characterized with particle size distribution and SEM images. Additionally, they are tested as reference material candidate according to homogeneity and stability for particle number with µ-IR and µ-Raman as well as on particle mass with Py-GC/MS and TED-GC/MS after ISO Guide 35. Results are promising. The material passed the homogeneity control. No changes are observed within 6 months of storage. The same tested reference material is finally used in sample preparation experiments, where environmental suspended particular matter from surface water or baby milk powders are spiked with the tablets. T2 - ESOPS CY - Berlin, Germany DA - 09.09.2024 KW - Microplastics KW - TED-GC/MS KW - Reference materials KW - Polymer 3R KW - Tablets PY - 2024 AN - OPUS4-61017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Smales, Glen J. A1 - Appel, Paul Alexander A1 - Breßler, Ingo A1 - Chambers, Aaron A1 - Dumele, Oliver A1 - Ebisch, Maximilian A1 - Frontzek, Julius A1 - del Refugio Monroy, José A1 - Rosalie, Julian M. A1 - Pauw, Brian R. T1 - DACHS and RoWaN: The Automated and Traceable Synthesis of ZIF-8 N2 - Automated synthesis and open-data practices are increasingly seen as key enablers of transparent, traceable, and reproducible science. By combining automation with structured, metadata-rich documentation, it becomes possible to systematically com- pare synthesis strategies and link outcomes to detailed parameters. In this work, we implement such an approach to study the synthesis of ZIF-8, comparing hand and automation-assisted methods under controlled conditions. Using over 100 synthesis experiments, we assess the repeatability of particle size and yield, and explore how variations in mixing and injection influence outcomes. This study demonstrates how traceable synthesis workflows can support repeatability and comparison across synthe- sis strategies. The DACHS (Database for Automation, Characterization and Holistic Synthesis) framework underpins this work, providing a lightweight infrastructure for transparent synthesis data capture. KW - Automation KW - MOFs KW - SAXS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645861 DO - https://doi.org/10.26434/chemrxiv-2025-7fgg0 SP - 1 EP - 32 PB - Cambridge AN - OPUS4-64586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Chasing perfection: A holistic approach to materials science scattering experiments N2 - The materials scientists we work with do not want (or need) to learn the ways of the scatterer; they are primarily interested in obtaining trustworthy answers. In particular, they need structural understanding in light of the wider framework of their experiment(s). Our interest, therefore, lies in helping them attain this this interconnected understanding, while using such investigations to further hone our methodology to approximate perfection. While perfection is by definition an unattainable goal, we have spent the last 15+ years exploring and expanding on many of its constituent aspects (often together with likeminded people) [1]. These aspects include: - developing various visualization and simulation tools, - deconstructing data corrections and uncertainty estimation, - advancing analysis methods, - quantifying questions on traceability, documentation, - reproducible automation of synthesis-, measurement- and data pipelines, - data visualization, exploration and education, - and many more… T2 - XIX International Small Angle Scattering Conference CY - Taipei, Taiwan DA - 04.11.2024 KW - Methodology KW - X-ray scattering KW - Data quality KW - Data provenance KW - Data stewardship KW - Lab automation KW - Perfection PY - 2024 AN - OPUS4-61625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard T1 - DACHS/MOFs/AutoMOFs_2/Synthesis N2 - The DACHS (Database for Automation, Characterization and Holistic Synthesis) project aims to create completely traceable experimental data, covering syntheses, measurements, analyses, and interpretations. DACHS_MOFs focuses on the synthesis and characterisation of metal-organic frameworks, across multiple, automation-assisted experimental series (AutoMOFs), with the overall goal of producing reproducible MOF samples through tracking of the synthesis parameters. DACHS_MOFs is simultaneously used to test the DACHS principles. This upload contain synthesis data from AutoMOFs_2 in HDF5 format (.h5). Each .h5 file contains detailed information on the chemical, experimenal, and synthesis parameters used during the synthesis of a single AutoMOF sample. KW - Automation KW - Procedure KW - Synthesis KW - Traceability PY - 2024 DO - https://doi.org/10.5281/zenodo.11236074 PB - Zenodo CY - Geneva AN - OPUS4-60611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diehn, S. A1 - Zimmermann, B. A1 - Tafintseva, V. A1 - Seifert, S. A1 - Bagcioglu, M. A1 - Ohlson, M. A1 - Weidner, Steffen A1 - Fjellheim, S. A1 - Kohler, A. A1 - Kneipp, Janina T1 - Combining Chemical Information From Grass Pollen in Multimodal Characterization N2 - The analysis of pollen chemical composition is important to many fields, including agriculture, plant physiology, ecology, allergology, and climate studies. Here, the potential of a combination of different spectroscopic and spectrometric methods regarding the characterization of small biochemical differences between pollen samples was evaluated using multivariate statistical approaches. Pollen samples, collected from three populations of the grass Poa alpina, were analyzed using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, surface enhanced Raman scattering (SERS), and matrix assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The variation in the sample set can be described in a hierarchical framework comprising three populations of the same grass species and four different growth conditions of the parent plants for each of the populations. Therefore, the data set can work here as a model system to evaluate the classification and characterization ability of the different spectroscopic and spectrometric methods. ANOVA Simultaneous Component Analysis (ASCA) was applied to achieve a separation of different sources of variance in the complex sample set. Since the chosen methods and sample preparations probe different parts and/or molecular constituents of the pollen grains, complementary information about the chemical composition of the pollen can be obtained. By using consensus principal component analysis (CPCA), data from the different methods are linked together. This enables an investigation of the underlying global information, since complementary chemical data are combined. The molecular information from four spectroscopies was combined with phenotypical information gathered from the parent plants, thereby helping to potentially link pollen chemistry to other biotic and abiotic parameters. KW - Pollen KW - MALDI-TOF MS KW - FTIR KW - Raman KW - Multivariate analyses PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504822 DO - https://doi.org/10.3389/fpls.2019.01788 VL - 10 SP - 1788 AN - OPUS4-50482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. A1 - Weidner, Steffen T1 - Low Molar Mass Cyclic Poly(L-lactide)s: Separate Transesterification Reactions of Cycles and Linear Chains in the Solid State N2 - L-Lactide (LA) was polymerized with neat tin(II) 2-ethylhexanoate (SnOct2) in toluene at 115 °C at low concentration with variation of the LA/Cat ratio. Cyclic polylactides (cPLAs) with number average molecular weights (Mn) between 7 000 and 17 000 were obtained. MALDI-TOF mass spectrometry also revealed the formation of a few percent of linear chains. Crystalline cPLAs with Mn around 9 000 and 14 000 were annealed at 140 °C in the presence of ScOct2 or dibutyl-2-stanna-1,3-dithiolane (DSTL). Simultaneously, crystallites of extended linear chains and crystallites of extended cycles were formed regardless of the catalyst, indicating that transesterification reaction proceeded different for linear chains and for cycles, governed by thermodynamic control. The formation of extended chain crystallites with low dispersity indicates the existence of symproportionation of short and long chains. A complementary experiment was carried out with a PLA ethyl ester composed mainly of linear chains with a small fraction of cycles KW - Polylactide KW - MALDI-TOF MS KW - Annealing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-606228 DO - https://doi.org/10.1039/D4SM00567H SN - 1744-6848 SP - 1 EP - 12 PB - Royal Society of Chemistry (RSC) AN - OPUS4-60622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dalgic, Mete-Sungur A1 - Weidner, Steffen T1 - Solvent-free sample preparation for matrix-assisted laserdesorption/ionization time-of-flight mass spectrometry ofpolymer blends N2 - Solvent-free sample preparation offers some advantages over solvent-based techniques, such as improved accuracy, reproducibility and sensitivity, for matrix-assisted laser desorption/ionization (MALDI) analysis. However, little or no information is available on the application of solvent-free techniques for the MALDI analysis of polymer blends. Solvent-free sample preparation by ball milling was applied with varying sample-to-matrix ratios for MALDI time-of-flight mass spectrometry analysis of various polymers, including polystyrenes, poly(methyl methacrylate)s and poly(ethylene glycol)s. The peak intensity ratios were compared with those obtained after using the conventional dried droplet sample preparation method. In addition, solvent-assisted milling was also applied to improve sample homogeneities. Depending on the sample preparation method used, different peak intensity ratios were found, showing varying degrees of suppression of the signal intensities of higher mass polymers. Ball milling for up to 30 min was required to achieve constant intensity ratios indicating homogeneous mixtures. The use of wet-assisted grinding to improve the homogeneity of the blends was found to be disadvantageous as it caused partial degradation and mass-dependent segregation of the polymers in the vials.The results clearly show that solvent-free sample preparation must be carefully considered when applied to synthetic polymer blends, as it may cause additional problems with regard to homogeneity and stability of the blends. KW - MALDI TOF MS KW - Sample preparation KW - Polymer blends KW - Solvent-free PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598570 DO - https://doi.org/10.1002/rcm.9756 SN - 0951-4198 VL - 38 IS - 12 SP - 1 EP - 9 PB - Wiley online library AN - OPUS4-59857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, A. A1 - Kricheldorf, H. T1 - Transformation of poly(L-lactide) crystals composed of linear chains into crystals composed of cycles N2 - A poly(L-lactide) with a trifluoroethyl ester end group and an average degree of polymerization (DP) of 50 was synthesized by ROP of L-lactide initiated with trifluoroethanol. Small-angle X-ray scattering (SAXS) in combination with differential scanning calorimetry (DSC) measurements revealed an average crystal thickness of 13 nm, corresponding to 45 repeat units. This suggests that most crystallites were formed by extended PLA chains, and both flat surfaces were covered by CF3 groups. The crystalline PLAs were annealed at 140 or 160 °C in the presence of two catalysts: tin(II) 2-ethylhexanoate, (SnOct2) or dibutyltin bis(pentafluorophenoxide) (BuSnPhF). The chemical reactions, such as polycondensation and cyclization, proceeded in the solid state and were monitored by matrix-assisted laser desorption/ionization time-offlight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC) measurements. Under optimal conditions a large fraction of linear chains was transformed into crystallites composed of extended cycles. Additionally, MALDI TOF MS analysis of GPC fractions from samples annealed for 28 or 42 days detected chain elongation of the linear species up to a factor of 20. KW - Polylactide KW - MALDI-TOF MS KW - Crystalinity KW - Transesterification PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597250 DO - https://doi.org/10.1039/D3PY01370G SN - 1759-9954 VL - 15 IS - 12 SP - 1173 EP - 1181 PB - Royal Society for Chemistry AN - OPUS4-59725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -