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 - CONF
A1 - Hufgard, Josefin
T1 - AIM Forward: Acoustic Ion Manipulation for Efficient Ambient-Pressure Ion Control
N2 - In ion-based spectrometry techniques the possibility to manipulate ions is fundamentally important. Currently used ion optics mostly rely on magnetic or electric fields. The electromagnetic forces compete with ion diffusion and are therefore most effective under low-pressure conditions. Therefore, high-pressure ion optics pose challenges related to elevated powers and potentials as well as complex structures and electrode contamination. Acoustic Ion Manipulation (AIM) is a recently discovered phenomenon that relies on the unique interactions between gas-phase ions and acoustic waves. This presentation shows selected patterns of ion manipulation, highlights the flexibility of AIM and discusses its current limitations and potentials.
T2 - DGMS Annual Conference 2026
CY - Leipzig, Germany
DA - 10.03.2026
KW - Acoustic ion manipulation
KW - Mass spectrometry
PY - 2026
AN - OPUS4-65680
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - El Abbassi, Abdelouahad
A1 - Krenzer, Julius
A1 - Petrov, Eugene P.
A1 - Biesen, Lukas
A1 - Vasylyeva, Vera
A1 - Merzenich, Sarah
A1 - Resch-Genger, Ute
A1 - Müller, Thomas J. J.
T1 - Aroyl-S,N-ketene acetal-triarylamine bichromophores – intramolecular energy transfer and dual emission upon induced aggregation and encapsulation
N2 - Aroyl-S,N-ketene acetal-based bichromophores are synthesized by a catalytic aryl amination and their photophysics are studied in the solid state, in ethanol–water mixtures inducing aggregation, and after encapsulation in polystyrene nanoparticles. The dye substitution pattern controls aggregation-induced emission and intramolecular energy transfer efficiency, resulting in single-band or dual fluorescence and a strong increase in fluorescence quantum yield upon particle encapsulation.
KW - Fluorescence
KW - Dye
KW - Aggregation
KW - Photophysics
KW - Enhancement
KW - White light emission
KW - Energy transfer
KW - Quantum yield
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656700
DO - https://doi.org/10.1039/d5ra09361a
SN - 2046-2069
VL - 16
IS - 11
SP - 10255
EP - 10260
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65670
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - 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 - JOUR
A1 - Tannenberg, Robert
A1 - Tscheuschner, Georg
A1 - Raab, Christopher
A1 - Flemig, Sabine
A1 - Döring, Sarah
A1 - Ponader, Marco
A1 - Thurmann, Melinda
A1 - Paul, Martin
A1 - Weller, Michael G.
T1 - Simplified Sample Preparation and Lateral Flow Immunoassay for the Detection of Plant Viruses
N2 - Lateral flow immunoassays (LFAs) are widely used for on-site testing; however, their use for the rapid detection of plant viruses in the field is often limited by inconvenient sample preparation. Here, we present a new sampling method and a simplified dipstick LFA format for the detection and monitoring of cowpea chlorotic mottle virus (CCMV) as a model plant pathogen. The assay employs a monoclonal mouse antibody for capture and a poly-clonal rabbit antibody conjugated to 80 nm gold nanoparticles for detection. Conventional sample and conjugate pads are omitted, allowing the test strips to be dipped directly into wells containing plant extract and antibody–gold conjugate. No plastic casing was required, which could lead to a reduction in waste. It was shown that CCMV concentrations as low as 3.5 µg/L or 350 pg per sample could be reliably detected in 15 min. Specificity tests confirmed that other plant viruses, cowpea mosaic virus (CPMV) and tobacco mosaic virus (TMV), did not produce false-positive results. In addition, we describe a new method for on-site sampling using a manual punch and a syringe equipped with a frit. This step combines grinding the sample, extraction, filtration, and reconstitution and mixing of the antibody-gold conjugate, enabling the analysis of punched leaf disks without laboratory equipment. When applied to CCMV-infected cowpea plants, the assay revealed systemic infection before visual symptoms became apparent. This work demonstrates that simplified LFAs combined with innovative sampling techniques can provide sensitive, specific, and rapid diagnostics for crop monitoring and support early intervention strategies in agriculture.
N2 - Lateral-Flow-Immunoassays (LFAs) werden häufig für Vor-Ort-Tests eingesetzt; ihr Einsatz zum schnellen Nachweis von Pflanzenviren im Feld wird jedoch oft durch eine umständliche Probenvorbereitung eingeschränkt. Hier stellen wir eine neue Probenahmemethode und ein vereinfachtes Dipstick-LFA-Format zum Nachweis und zur Überwachung des Cowpea Chlorotic Mottle Virus (CCMV) als Modellpflanzenpathogen vor. Der Test verwendet einen monoklonalen Maus-Antikörper zur Bindung und einen polyklonalen Kaninchen-Antikörper, der an 80-nm-Goldnanopartikel konjugiert ist, zum Nachweis. Herkömmliche Proben- und Konjugatpads entfallen, sodass die Teststreifen direkt in Vertiefungen getaucht werden können, die Pflanzenextrakt und das Antikörper-Gold-Konjugat enthalten. Es ist keine Kunststoffhülle erforderlich, was zu einer Reduzierung des Abfallaufkommens führen könnte. Es zeigte sich, dass CCMV-Konzentrationen von nur 3,5 µg/L oder 350 pg pro Probe innerhalb von 15 Minuten zuverlässig nachgewiesen werden konnten. Spezifitätstests bestätigten, dass andere Pflanzenviren, das Cowpea Mosaic Virus (CPMV) und das Tobacco Mosaic Virus (TMV), keine falsch-positiven Ergebnisse lieferten. Darüber hinaus beschreiben wir eine neue Methode zur Probenahme vor Ort unter Verwendung eines manuellen Lochers und einer mit einer Fritte ausgestatteten Spritze. Dieser Schritt kombiniert das Zerkleinern der Probe, die Extraktion, die Filtration sowie die Rekonstitution und das Mischen des Antikörper-Gold-Konjugats und ermöglicht so die Analyse der ausgestanzten Blattscheiben ohne Laborausrüstung. Bei der Anwendung an mit CCMV infizierten Augenbohnenpflanzen zeigte der Assay eine systemische Infektion, bevor visuelle Symptome erkennbar wurden. Diese Arbeit zeigt, dass vereinfachte LFAs in Kombination mit innovativen Probenahmetechniken eine sensitive, spezifische und schnelle Diagnostik für die Pflanzenüberwachung bieten und Strategien zur frühzeitigen Intervention in der Landwirtschaft unterstützen können.
KW - Point-of-care diagnostics
KW - Dipstick immunoassay
KW - Pre-symptomatic detection
KW - Precision agriculture
KW - Integrated pest management
KW - Crop health monitoring
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657039
DO - https://doi.org/10.3390/bios16020100
SN - 2079-6374
VL - 16
IS - 2
SP - 1
EP - 16
PB - MDPI AG
CY - Basle, Switzerland
AN - OPUS4-65703
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Herter, Sven-Oliver
T1 - Quantifizierung von Mutterkornalkaloiden in Lebensmitteln unter Verwendung neu entwickelter stabil isotopenmarkierter interner Standards
N2 - Mutterkornalkaloide sind Mykotoxine, die von Pilzen der Gattung Claviceps produziert werden und häufig in Roggen- und Weizenprodukten vorkommen. Aufgrund ihrer toxikologischen Relevanz hat die Europäische Union im Jahr 2022 erstmals Grenzwerte für diese Alkaloide in Lebensmitteln eingeführt. Eine zuverlässige Quantifizierung ist essenziell für die Überwachung der Lebensmittelsicherheit. Allerdings stellte der bisherige Mangel an stabilen isotopenmarkierten (SIL - stable isotopically labeled) Standards eine wesentliche Herausforderung für die Entwicklung präziser Analysemethoden mittels HPLC-MS/MS dar.
Um diese Lücke zu schließen, wurden erstmals alle zwölf prioritären Mutterkornalkaloide über einen einheitlichen Semisyntheseansatz als 13CD3-markierte Analoga synthetisiert und als interne Standards für die massenspektrometrische Analyse eingesetzt. Die Quantifizierung erfolgte mittels HPLC-MS/MS in verschiedenen Lebensmittelmatrizes, darunter Brot, Roggen- und Weizenmehl sowie Kleie. Zur Evaluierung der SIL-Standards wurden etablierte Methoden wie externe Kalibrierung und Standardaddition herangezogen.
Die Studienergebnisse zeigen, dass der Einsatz von SIL-Standards die Genauigkeit und Präzision der Mutterkornalkaloid-Quantifizierung signifikant verbessert. Dies ist insbesondere auf die Korrektur von Matrixeffekten, Extraktions- und Signalschwankungen während der massenspektrometrischen Analyse zurückzuführen. Die neu synthetisierten 13CD3 markierten Mutterkornalkaloide stellen daher ein wertvolles Werkzeug zur Verbesserung der Lebensmittelsicherheit dar, da sie zuverlässigere und reproduzierbare Messergebnisse ermöglichen. Darüber hinaus leisten diese Ergebnisse einen wichtigen Beitrag zur Weiterentwicklung analytischer Methoden zur Überwachung von Mutterkornalkaloiden und damit zur Sicherstellung der Lebensmittelqualität.
T2 - 53. Deutsche Lebensmittelchemietage
CY - Halle (Saale), Germany
DA - 22.09.2025
KW - HPLC-MS/MS
KW - Interner Standard
KW - Qualitätssicherung
PY - 2025
AN - OPUS4-64546
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Henning, Thorsten
A1 - Goerdeler, Cornelius
A1 - El-Khatib, Ahmed H.
A1 - Meyer, Klas
A1 - Bruer, Gustav G.
A1 - Abraham, Klaus
A1 - Monien, Bernhard
T1 - Characterization and quantitation of urinary metabolites of 3-monochloropropane-1,2-diol (3-MCPD) in rats
N2 - Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD) are heat-induced contaminants formed from fats and sodium chloride. The mode of action for the 3-MCPD mediated induction of renal tubule neoplasms in rats is still unclear, which is in part due to lacking metabolism data. In the current study, urinary metabolites were identified by one- and two-dimensional 13C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry following oral administration of 3-MCPD or [13C3]3-MCPD in rats. In addition to 3-MCPD itself, nine metabolites were identified. Four of those, N-acetyl-S-(2,3-dihydroxypropyl)cysteine (DHPMA), 3-MCPD sulfate, β-chlorolactic acid (β-ClLA) and oxalic acid have been reported before. Five novel metabolites in rat urine were thiodiglycolic acid (TDGA), thionyldiglycolic acid (TNDGA), 3-MCPD glucuronide (at least three isomers), 3-carboxy-2-hydroxypropyl mercapturic acid (CHPMA), and 3-(S-carboxymethyl)mercaptolactic acid (CMMLA). Only three metabolites were excreted at mean dose ratios > 1% (after treatment with 50 mg 3-MCPD/kg body weight in male and female rats), i.e. 3-MCPD (7.3%, 9.7%), DHPMA (3.5%, 1.7%) and TDGA (1.1%, 4.0%). The overall mean dose excretion in urine samples (males: 12.2%, females: 16.3%) supported hypotheses on formation of conjugates/adducts of reactive metabolites and the possibility that dechlorination leads to suitable building blocks for amino acid and fatty acid synthesis. The identification of TDGA indicated the interim formation 2-chloroacetaldehyde, previously identified to mediate specific nephrotoxic effects of the cytostatic ifosfamide in rats.
KW - 3-Monochloropropane-1,2-diol
KW - 3-MCPD
KW - Metabolism
KW - Urine
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657230
DO - https://doi.org/10.1007/s00204-026-04318-x
SP - 1
EP - 17
PB - Springer-Verlag GmbH
CY - Heidelberg
AN - OPUS4-65723
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Altmann, Korinna
A1 - Abusafia, A
A1 - Bannick, C-G
A1 - Braun, U
A1 - Crasselt, Claudia
A1 - Dittmar, S
A1 - Fuchs, M
A1 - Gehde, M
A1 - Hagendorf, C
A1 - Heller, C
A1 - Herper, D
A1 - Heymann, S
A1 - Kerndorff, A
A1 - Knefel, M
A1 - Jekel, M
A1 - Lelonek, M
A1 - Lunkenbein, T
A1 - Obermaier, N
A1 - Manhart, M
A1 - Meurer, Maren
A1 - Miclea, P-T
A1 - Paul, A
A1 - Richter, S
A1 - Ricking, M
A1 - Rohner, C
A1 - Ruhl, A
A1 - Sakai, Y
A1 - Saravia Arzabe, C
A1 - Scheid, C
A1 - Schmitt, M
A1 - Schnarr, M
A1 - Schwertfirm, F
A1 - Steinmetz, H
A1 - Wander, Lukas
A1 - Wiesner, Yosri
A1 - Zechmeister, L
T1 - RUSEKU - Repräsentative Untersuchungsstrategien für ein integratives Systemverständnis von spezifischen Einträgen von Kunststoffen in die Umwelt : Abschlussbericht
N2 - Im Verbundprojekt RUSEKU wurde die Probenahme von Wasserproben entscheidend weiterentwickelt. Wichtig ist hierbei zu gewährleisten, dass genügend Merkmalsträger in jeder Probe untersucht werden. Es muss daher eine für den Probenahmeort repräsentative Beprobung hinsichtlich des Wasservolumens in Abhängigkeit der Partikelanzahl gewährleistet sein.
Das Hauptaugenmerk lag im vorliegenden Projekt auf einer praxisnahen Beprobungsstrategie. Es wurden verschiedene Konzepte ausprobiert.
• Grundsätzlich hat sich gezeigt, dass eine Stichprobe eine Momentaufnahme des MP-Massengehaltes zeigt. Es wird eine hohe Statistik, also eine Vielzahl an Messungen am gleichen Probenahmeort, benötigt, um eine valide Aussage über den MP-Gehalt zu machen.
• Es zeigt sich, dass eine integrale Probenahme über mehrere Wochen mit dem SK routinemäßig möglich ist. Die erfassten MP-Massen sind reproduzierbar und robust.
• Die DFZ ist für Stichproben geeignet. Partikel < 50 µm werden eventuell unterschätzt
• Die fraktionierte Filtration kann für Stich- und Mischproben direkt im Feld genutzt werden. Fraktionen von 10 und 5 µm werden später im Labor Vakuum filtriert. Es erfolgt eine Fraktionierung der Probe mit Siebmaschenweiten von 1000, 500, 100, 50, 10 und 5 µm.
• Die fraktionierte Filtration kann auch anschließend an die Beprobung mit dem SK zur Anwendung kommen. Wird die mit dem SK gewonnene Wasserprobe fraktioniert filtriert, kann neben einem MP-Gesamtgehalt auch eine Einschätzung über die Partikelgrößen gewonnen werden.
• Für Wässer mit geringen Partikelzahlen wurde ein Messfiltertiegel entwickelt. Dieser hat eine Maschenweite von 6 µm. Seine Anwendung kann mögliche Verluste beim Transferieren vom Probenahmetool zum Messgefäß und mögliche Kontaminationen reduzieren.
Die Optimierung der Probenahmestrategie wurde durch Modellversuche und Simulationen unterstützt. Modellversuche zum Sinkverhalten und Simulationen von MP in realen Gewässern verdeutlichten das komplexe Verhalten der Partikel. Es konnte gezeigt werden, dass Partikel ab einer bestimmten Größe (und kleiner) bei genügend starker Turbulenz sich in der Wassersäule unabhängig von ihrer Dichte verhalten und so auch MP mit kleiner Dichte (z.B. PE) in der gesamten Wassersäule zu finden sind. Es konnte mit dem TEM die Existenz von NP gezeigt werden.
Ein wesentlicher Aspekt des RUSEKU Projektes war die Beprobung realer Kompartimente. Beprobt wurde neben Oberflächengewässern, das urbane Abwassersystem der Stadt Kaiserslautern, Waschmaschinenabwasser und Flaschenwasser.
• In Oberflächengewässern wurde hauptsächlich PE gefunden. Je nach Probe und Gewässer konnten auch PP, PS, PET, PA, SBR und Acrylate nachgewiesen werden.
• Im urbanen Abwassersystem der Stadt Kaiserslautern konnte an allen Probenahmestandorten MP nachgewiesen werden. Es wurde hauptsächlich PE, neben geringeren Mengen an PP, PS und SBR gefunden. Nach einem Regenereignis war der SBR Anteil deutlich erhöht.
• Die Beprobung eines realen Wäschepostens, bestehend aus T-Shirts und Hemden mit PA/CO oder PES/CO Mischgewebe, zeigte einen PA- und PES-Austrag im Waschwasser. Der überwiegende Teil der detektierten Fasern ist aber auf Baumwolle zurückzuführen. Reine gravimetrische Messungen zur Detektion von MP führen zu einer starken Überschätzung.
• In Flaschenwasser (PET-Flaschen) konnte MP detektiert werden. PET wurde nur im stillen Mineralwasser, nicht in Mineralwasser mit Kohlensäure gefunden werden. Teilweise wurde auch das MP-Material des Verschlusses im Wasser detektiert.
• Für Luftproben konnte ein Aufbau zur größenselektiven Beprobung getestet werden.
Neben der Probenahme hat das Projekt auch gezeigt, dass die TED-GC/MS geeignet für die MP-Detektion im Routinebetrieb ist. Die TED-GC/MS konnte weiter optimiert werden. Es wurden MP-Massen bestimmt.
Im Projekt wurden erste realitätsnahe Referenzmaterialien für die MP Detektion hergestellt. Die Herstellung von realitätsnahen Polymeren in ausreichender Homogenität und Menge hat sich als große Herausforderung herausgestellt.
KW - Mikroplastik
KW - Probennahme
KW - TED-GC/MS
KW - Fraktionierte Filtration
KW - Mikroplastikreferenzmaterial
PY - 2022
SP - 1
EP - 201
AN - OPUS4-57800
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - 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 - JOUR
A1 - Döring, Sarah
A1 - Wulfes, Birte S.
A1 - Atanasova, Aleksandra
A1 - Jaeger, Carsten
A1 - Walzel, Leopold
A1 - Tscheuschner, Georg
A1 - Flemig, Sabine
A1 - Gawlitza, Kornelia
A1 - Feldmann, Ines
A1 - Konthur, Zoltán
A1 - Weller, Michael G.
T1 - Corundum Particles as Trypsin Carrier for Efficient Protein Digestion
N2 - Reusable enzyme carriers are valuable for proteomic workflows, yet many supports are expensive or lack robustness. This study describes the covalent immobilization of recombinant trypsin on micrometer-sized corundum particles and assesses their performance in protein digestion and antibody analysis. The corundum surface was cleaned with potassium hydroxide, silanized with 3-aminopropyltriethoxysilane and activated with glutaraldehyde. Recombinant trypsin was then attached, and the resulting imines were reduced with sodium cyanoborohydride. Aromatic amino acid analysis (AAAA) estimated an enzyme loading of approximately 1 µg/mg. Non-specific adsorption of human plasma proteins was suppressed by blocking residual aldehydes with a Tris-glycine-lysine buffer. Compared with free trypsin, immobilization shifted the temperature optimum from 50 to 60 °C and greatly improved stability in 1 M guanidinium hydrochloride. Activity remained above 80% across several reuse cycles, and storage at 4 °C preserved functionality for weeks. When applied to digesting the NISTmAb, immobilized trypsin provided peptide yields and sequence coverage comparable to soluble enzyme and outperformed it at elevated temperatures. MALDI-TOF MS analysis of Herceptin digests yielded fingerprint spectra that correctly identified the antibody and achieved 60% sequence coverage. The combination of low cost, robustness and analytical performance makes corundum-immobilized trypsin an attractive option for research and routine proteomic workflows.
N2 - Wiederverwendbare Enzymcarrier sind für proteomische Arbeitsabläufe von großem Wert, doch viele Trägermaterialien sind teuer oder nicht robust genug. Diese Studie beschreibt die kovalente Immobilisierung von rekombinantem Trypsin auf mikrometergroßen Korundpartikeln und bewertet deren Leistungsfähigkeit beim Proteinverdau und der Antikörperanalyse. Die Korundoberfläche wurde mit Kaliumhydroxid gereinigt, mit 3-Aminopropyltriethoxysilan silanisiert und mit Glutaraldehyd aktiviert. Anschließend wurde rekombinantes Trypsin gebunden, und die entstandenen Imine wurden mit Natriumcyanoborhydrid reduziert. Die aromatische Aminosäureanalyse (AAAA) ergab eine geschätzte Enzymbeladung von etwa 1 µg/mg. Die unspezifische Adsorption von menschlichen Plasmaproteinen wurde durch Blockierung der restlichen Aldehyde mit einem Tris-Glycin-Lysin-Puffer unterdrückt. Im Vergleich zu freiem Trypsin verschob die Immobilisierung das Temperaturoptimum von 50 auf 60 °C und verbesserte die Stabilität in 1 M Guanidiniumhydrochlorid erheblich. Die Aktivität blieb über mehrere Wiederverwendungszyklen hinweg bei über 80 %, und die Lagerung bei 4 °C bewahrte die Funktionalität über Wochen hinweg. Beim Verdau des NISTmAb lieferte das immobilisierte Trypsin Peptidausbeuten und Sequenzabdeckungen, die mit denen des löslichen Enzyms vergleichbar waren, und übertraf dieses bei erhöhten Temperaturen. Die MALDI-TOF-MS-Analyse von Herceptin-Verdauen ergab Fingerabdruck-Spektren, die den Antikörper korrekt identifizierten und eine Sequenzabdeckung von 60 % erreichten. Die Kombination aus niedrigen Kosten, Robustheit und analytischer Leistungsfähigkeit macht auf Korund immobilisiertes Trypsin zu einer attraktiven Option für die Forschung und routinemäßige proteomische Arbeitsabläufe.
KW - Bottom-up proteomics
KW - Solid-phase digestion
KW - Biopharmaceutical analysis
KW - Peptide mapping
KW - Non-specific binding
KW - amino acid analysis
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657021
DO - https://doi.org/10.3390/biotech15010002
SN - 2673-6284
VL - 15
IS - 1
SP - 1
EP - 23
PB - MDPI
CY - Basel
AN - OPUS4-65702
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Singh, Chandan
T1 - Oxidation resistant, interlaced 3D MXene composite for electrochemical biosensing
N2 - BSA (Bovine Serum Albumin) as an oxidation resistant for Ti₃C₂Tx-MXene : BSA derived method protects 3D interlaced Ti₃C₂Tx–CNT nanocomposite from oxidative degradation, preserving their structural integrity . Application in biosensing: After the removal of excess BSA, the nanocomposite were amino-silane functionalized and decorated with anti-SARS-CoV-2 antibodies, enabling selective detection of SARS-CoV-2 nucleocapsid protein (SNP) in saliva. Performance of the biosensor: The designed biosensor showed high sensitivity (LoD 23.6 pM), wide detection range (0.1–500 ng/mL), no cross-reactivity, and improved response due to the preserved 3D interwoven nanostructure.
T2 - Graphene Week 2025
CY - Vicenza, Italy
DA - 22.09.2025
KW - Nanocomposite
KW - Biosensor
KW - SARS-CoV-2
PY - 2025
AN - OPUS4-65728
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kumari, Surbhi
T1 - Tagetes erecta synthesized bimetallic Ag–Au nanoparticles and their potential application in electrochemical detection and estimation of ampicillin in raw milk
N2 - This study focuses on the green synthesis of Ag–Au nanoparticles using Tagetes erecta extract and their potential application in electrochemical detection and estimation of ampicillin in raw milk. The Ag–Au nanoparticles were covalently bonded to the hydroxylated fluorine-doped tin oxide electrode surface through silane chemistry enabling the effective interaction of the 5' thiolated-aptamer with the nanoparticle-modified surface for aptasensor development. The aptasensor displayed a limit of detection of 0.40 ng mL−1 and a stability of 30 days. Moreover, the aptasensor demonstrated reliable performance with both spiked milk samples and real milk samples, detecting a concentration of 194 ng mL−1 in raw milk with results closely matching with those obtained by the LC-MS technique.
T2 - SALSA Make & Measure 2025: Interfaces
CY - Berlin, Germany
DA - 10.09.2025
KW - Aptamer
KW - Antibiotic
KW - Biosensing
PY - 2025
AN - OPUS4-65727
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Meyer, Klas
T1 - Benchtop NMR-Spektroskopie im industriellen Produktionsumfeld: Herausforderungen auf dem Weg zur Online-Prozessintegration
N2 - Benchtop-NMR Spektrometer erobern erfolgreich seit Jahren die Labore und haben sich als ein vielseitiges analytisches Werkzeug etabliert. Zunächst stark fokussiert auf den Forschungs-bereich, sind sie heute zunehmend auch nahe der Produktion auf dem Vormarsch. Die Zielstellung ist nur selten der Ersatz von klassischer „Hochfeld“-NMR-Spektroskopie. Vielmehr erschließen die kompakten Geräte oftmals neue Anwendungsfelder, beispielsweise in der Online-Reaktionsverfolgung im Labor oder der schnellen at-line Qualitätskontrolle in der chemischen Produktion. Hier kommen die Vorteile der geringeren Anschaffungs- und Betriebskosten, die Möglichkeit des prozessnahen Einsatzes, sowie besonders der einfachen Bedienung zum Tragen.
Während es zahlreiche Beispiele von Online-Applikationen im Labor gibt, ist die direkte Einbindung in großtechnische Produktionsanlagen bislang selten. Im Vergleich zu etablierten prozessanalytischen Verfahren, wie z.B. der Nahinfrarot- oder Raman-Spektroskopie ist die Benchtop-NMR-Spektroskopie noch Neuland und es existieren kaum prozesstaugliche kommerzielle Lösungen.
Im Rahmen eines gemeinsamen Entwicklungsprojekts zwischen BAM und Evonik wurde eine Einhausung für ein handelsübliches Benchtop-NMR-Spektrometer konzipiert und gebaut. Diese dient nicht nur der Erfüllung sicherheitstechnischer Auflagen wie dem Explosionsschutz, sondern auch der Abschirmung rauer Umgebungseinflüsse auf den Betrieb des Laborgeräts. Eine flexible integrierte Automatisierung ermöglicht die skalierbare Anbindung an übergeordnete Prozessleittechnik im Sinne eines PAT-Moduls.
Dieser Vortrag gibt einen Überblick über die Herausforderungen auf dem Weg von der Idee, über die Umsetzung bis hin zur tatsächlichen Prozessintegration.
T2 - 47. Praktische Probleme der Kernresonanzspektroskopie
CY - Göttingen, Germany
DA - 17.03.2026
KW - Prozessanalytik
KW - NMR Spektroskopie
KW - Feldintegration
KW - Explosionsschutz
PY - 2026
AN - OPUS4-65705
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pérez-Padilla, Víctor
A1 - Burnage, Samual C.
A1 - Wittwer, Philipp
A1 - Valderrey, Virginia
A1 - Bell, Jérémy
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
T1 - Detection of Perfluoroalkylic Acids From Water Using a Guanidine-Based Fluorescent Probe and Microfluidic Droplet Extraction
N2 - Perfluoroalkylic acids (PFAAs), a subclass of per- and polyfluoroalkyl substances (PFAS), are stable, widely used industrial compounds posing environmental concerns due to their persistence and toxicity. Regulatory actions and remediation strategies necessitate effective onsite analytical methods for PFAS management. We developed an optical sensing system using a fluorescent probe with a benzoxadiazole core and guanidine receptor in a droplet-based microfluidic assay to detect PFAAs in water samples with low detection limits. The PFAAs binding enhances the probe's fluorescence in organic media through protonation-mediated hydrogen bond-assisted ion pairing, exploiting two complementary supramolecular forces. Direct detection employs a liquid-liquid extraction protocol in the microfluidic device, achieving detection limits for PFOA and PFOS down to ≥0.5 µm, with a dynamic range up to 200 µm for sample volumes <100 µL. HCl/KCl buffering facilitates analyte desalting and phase transfer for quantitation from surface water. Additionally, we developed a method involving a thin polymer layer of the probe and a crosslinker on submicron silica particles for direct detection of PFAAs in water. Our approaches provide sensitive, direct recognition and indication of PFAAs, advancing the field beyond indirect sensing and offering improved background suppression, rapid assay times, and a modular design for targeting other PFAS subclasses.
KW - PFAS
KW - Fluorescence
KW - Microfluidics
KW - Droplet Extraction
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657330
DO - https://doi.org/10.1002/adsr.70145
VL - 5
IS - 3
SP - 1
EP - 13
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-65733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Devi, Sarita
A1 - Goel, S.
A1 - Rani, S.
A1 - Schneider, Rudolf J.
A1 - Rohilla, R.
A1 - Kumari, Surbhi
A1 - Prabhakar, N.
T1 - MOF-metal nanohybrid-assisted charge transfer amplification for electrochemical biosensing of the MUC1 cancer biomarker
N2 - Cancer is a severe disease characterized by high mortality and complex pathophysiology; however, its early and accurate diagnosis remains inadequate. Conventional diagnostic approaches often fall short, particularly for dense tissues, and are frequently invasive, costly, and of limited availability. This reinforces the need for a compact, economical, and ultrasensitive assay that is operationally simple and interpretable.
We present an efficient electrochemical detection platform for the cancer biomarker mucin 1 (MUC1). A fluorine-doped tin oxide (FTO) surface was modified with an iron-based metal–organic framework (FeMOF) intercalated with palladium nanorods (PdNR). FeMOF was prepared using Fe3+/Fe2+ precursors at a 1.2/1 mmol ratio and dual ligands, i.e. tetrahydroxy-1,4-benzoquinone and 2-aminobenzene-1,4-dicarboxylic acid. AntiMUC1 antibodies were immobilized on a modified electrode via p-phenylenediamine (PDA) (FTO/FeMOF@PdNR/PDA/antiMUC1Ab) and evaluated using electrochemical impedance spectroscopy (EIS) and voltammetry. The designed sensor demonstrated an excellent binding affinity for the MUC1 antigen. Among these techniques, the EIS method stands out for its technical performance, as evidenced by the high sensitivity (detection limit 0.074 fg mL−1), quantification limit 0.24 fg mL−1, and high analytical sensitivity (1.39 × 103 Ω fg−1 mL−1 cm−2). The negligible cross-reactivity with interferent biomolecules, rapid response (10-minute equilibrium), regenerability up to 5 cycles, high reproducibility (RSD ∼1–3%), and long-term stability (up to 35 days) further validate the suitability of the proposed MUC1 immunosensor. This study presents an ultrasensitive biosensor that is compact, cost-effective, and easy for individuals at home to use after further development into a kit-based end product. Moreover, its excellent functionality for spiked serum samples shows promise for next-generation clinical diagnostics.
KW - Antibodies
KW - Metal-organic framework
KW - Immunoassay
PY - 2026
DO - https://doi.org/10.1039/D6AN00018E
SP - 1
EP - 11
PB - Royal Society of Chemistry
CY - London
AN - OPUS4-65726
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - 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 -
TY - CONF
A1 - Recknagel, Sebastian
T1 - The digital reference material document - how to get standards into instruments
N2 - Activities of BAm on the transfer of paper-based RM-certificates into machine readable XML-documents, based on the digital calibration certificate are described and highlighted with examples
T2 - 2026 European Chemistry Meeting - Jernkontoret TO 45
CY - Stockholm, Sweden
DA - 18.03.2026
KW - Reference material
KW - Digital reference material document
PY - 2026
AN - OPUS4-65737
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Becker, Roland
A1 - Scholz, Philipp
A1 - Jung, Christian
A1 - Weidner, Steffen
T1 - Thermo-Desorption Gas Chromatography-Mass Spectrometry for investigating the thermal degradation of polyurethanes
N2 - Thermo-Desorption Gas Chromatography-Mass Spectrometry (TD-GC-MS) was used to investigate the thermal degradation of two different polyurethanes (PU). PU samples were heated at different heating rates and the desorbed products were collected in a cold injection system and thereafter submitted to GC-MS. Prospects and limitations of the detection and quantification of semi-volatile degradation products were investigated. A temperature dependent PU depolymerization was
found at temperatures above 200 °C proved by an increasing release of 1,4-butanediol and methylene diphenyl diisocyanate (MDI) representing the main building blocks of both polymers. Their release was monitored quantitatively based on external calibration with authentic compounds. Size Exclusion Chromatography (SEC) of the residues obtained after thermodesorption confirmed the initial competitive degradation mechanism indicating an equilibrium of crosslinking and depolymerization as previously suggested. Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry of SEC fractions of thermally degraded PUs provided additional hints on degradation mechanism.
KW - Thermo-desorption
KW - Mass spectrometry
KW - Polyurethanes
KW - Thermal degradation
PY - 2023
DO - https://doi.org/10.1039/D3AY00173C
SN - 1759-9660
SP - 1
EP - 6
PB - Royal Society for Chemistry
AN - OPUS4-57307
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, H. R.
A1 - Weidner, Steffen
A1 - Scheliga, F.
T1 - Synthesis of cyclic polymers and flaws of the Jacobson–Stockmayer theory
N2 - Cyclic poly(L-lactide)s were prepared by ring-opening polymerization combined with simultaneous polycondensation (ROPPOC) in bulk at 160 ° with dibutyltin bis(4-cyanophenoxide) as catalyst. It is demonstrated by MALDI TOF mass spectrometry and 1H NMR end group analyses that cycles are formed by endto-end cyclization in addition to “back-biting” transesterification. Formation of high molar mass cyclic poly L-lactide)s by means of several more reactive ROPPOC catalysts presented previously and in new experiments is discussed. These experimental results, together with theoretical arguments, prove that part of the Jacobson–Stockmayer theory is wrong. The critical monomer concentration, above which end-toend cyclization is seemingly impossible, does not exist and reversible like irreversible polycondensations can theoretically proceed up to 100% conversion, so that finally all reaction products will necessarily adopt a cyclic architecture.
KW - Polylactide
KW - MALDI-TOF MS
KW - Cyclization
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506419
DO - https://doi.org/10.1039/d0py00226g
VL - 11
IS - 14
SP - 2595
EP - 2604
PB - Royal Society for Chemistry
AN - OPUS4-50641
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 - Polycondensations and Cyclization of Poly(L-lactide) Ethyl Esters in the Solid State
N2 - The usefulness of seven different Tin catalysts, Bismuth subsalicylate and Titan tetra(ethoxide) for the polycondensation of ethyl L-lactate (ELA) was examined at 150 °C/6 d. Dibutyltin bis(phenoxides) proved to be particularly effective. Despite the low reactivity of ELA, weight average molecular masses (Mw) up to 12 500 were found along with partial crystallization. Furthermore, polylactides (PLAs) of similar molecular masses were prepared via ELA-initiated ROPs of L-lactide by means of the four most effective polycondensation catalysts. The crystalline linear PLAs were annealed at 140 or 160 °C in the presence of these catalysts. The consequences of the transesterification reactions in the solid PLAs were studied by means of matrix-assisted laser desorption/ionization (MALDI TOF) mass spectrometry, gel permeation chromatography (GPC) and small-angle X-ray scattering (SAXS). The results indicate that polycondensation and formation of cycles proceed in the solid state via formation of loops on the surface of the crystallites. In summary, five different transesterification reactions are required to explain all results.
KW - Polylactide
KW - MALDI-TOF MS
KW - Crystalinity
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592934
DO - https://doi.org/10.1039/d3py01232h
SN - 1759-9962
VL - 15
IS - 2
SP - 71
EP - 82
PB - RSC Publ.
CY - Cambridge
AN - OPUS4-59293
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Martins, Ines
A1 - Al-Sabbagh, Dominik
A1 - Bentrup, U.
A1 - Marquardt, Julien
A1 - Schmid, Thomas
A1 - Scoppola, E.
A1 - Kraus, Werner
A1 - Stawski, Tomasz
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Yusenko, Kirill
A1 - Weidner, Steffen
A1 - Emmerling, Franziska
T1 - Formation Mechanism of a Nano-Ring of Bismuth Cations and Mono-Lacunary Keggin-Type Phosphomolybdate
N2 - A new hetero-bimetallic polyoxometalate (POM) nano-ring was synthesized in a one-pot procedure. The structure consists of tetrameric units containing four bismuth-substituted monolacunary Keggin anions including distorted [BiO8] cubes. The nano-ring is formed via self-assembly from metal precursors in aqueous acidic medium. The compound (NH4)16[(BiPMo11O39)4] ⋅ 22 H2O; (P4Bi4Mo44) was characterized by single-crystal X-ray diffraction, extended X-ray absorption fine structure spectroscopy (EXAFS), Raman spectroscopy, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF), and thermogravimetry/differential scanning calorimetry mass spectrometry (TG-DSC-MS). The formation of the nano-ring in solution was studied by time-resolved in situ small- and wide-angle X-ray scattering (SAXS/WAXS) and in situ EXAFS measurements at the Mo−K and the Bi−L3 edge indicating a two-step process consisting of condensation of Mo-anions and formation of Bi−Mo-units followed by a rapid self-assembly to yield the final tetrameric ring structure.
KW - Bismuth
KW - In situ EXAFS
KW - In situ SAXS/WAXS
KW - Lacunary Keggin ion
KW - Polyoxometalates
KW - Self-assembly
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546823
DO - https://doi.org/10.1002/chem.202200079
SN - 0947-6539
VL - 28
IS - 27
SP - 1
EP - 7
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54682
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Meyer, Andreas
A1 - Weidner, Steffen
A1 - Kricheldorf, Hans R.
T1 - Star-shaped poly(l-lactide)s based on pentaerythritol: About crystallization and polycondensation plus disproportionation and ring formation in the solid state
N2 - Star-shaped poly( L-lactide)s (s-PLAs), were prepared by ring-opening polymerization of with pentaerythritol and catalyzed by tin(II) 2-ethylhyexanoate (SnOct out in bulk at either 120 ◦ C or 160 ◦ L-lactide (LA) initiated 2 ). Two small series of ROPs were carried C with variation of the LA/initiator ratio. Matrix-assisted laser desorption/ ionization time-of-flight (MALDI-TOF) mass spectra revealed traces of cycles in 120 ◦ C samples only at low initiator/catalyst ratios. In contrast, higher fractions of cycles were detected in samples prepared at 160 C, suggesting a "back-biting" origin. The influence of arm length and thermal history on crystallinity was investigated by differential scanning calorimetry (DSC) and wide-angle x-ray scattering (WAXS). It was shown that annealing increased the melting temperature (T ◦ ◦ m ) and crystallinity. However, annealing at 140 ◦ C for 14 d also caused significant solid-state transesterification. In addition, crystallites composed of s-PLAs with extended arms and, simultaneously, crystallites composed exclusively of extended rings were formed, identified by their typical "sawtooth" pattern in the MALDI mass spectra. Small angle x-ray scattering (SAXS) indicated that the crystal thickness was lower than that of linear PLAs annealed under identical conditions, but increased upon annealing at 140 C.
KW - MALDI-TOF MS
KW - Polylactide
KW - Crystallisation
KW - AStar-shaped polymers
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636832
DO - https://doi.org/10.1016/j.polymer.2025.128709
SN - 0032-3861
VL - 334
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-63683
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 H. E.
A1 - Schlaad, Helmut
T1 - Kinetics of anionic polymerization of β‐myrcene in hydrocarbon solvents
N2 - The 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.
KW - MALDI-TOF MS
KW - Anionic polymerization
KW - β‐myrcene
KW - Kinetics
KW - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculations
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630900
DO - https://doi.org/10.1002/pi.6772
SN - 1097-0126
SP - 1
EP - 8
PB - Wiley
CY - New York, NY
AN - OPUS4-63090
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, Hans R.
A1 - Weidner, Steffen
T1 - Polymerization of L‐Lactide Catalyzed by Metal Acetylacetonate Complexes
N2 - ABSTRACTRing‐opening polymerizations (ROPs) of l‐lactide (LA) were performed at 120°C, 140°C, 150°C, and 180°C in bulk catalyzed by acetylacetonate (acac) complexes of manganese(II), nickel(II), copper(II), zirconium(IV), dibutyltin(IV), and vanadyl(V). These experiments revealed that only the acac complexes of Zr and Bu2Sn were reactive enough to enable quantitative polymerization within a few hours. Further ROPs with Bu2Sn(acac)2 and Zr(acac)4 showed that Bu2Sn(acac)2 had a slightly lower reactivity than the Zr complex. The ROPs catalyzed with Zr(acac)4 yielded number average molecular weights (Mn) up to 70,000 g mol−1. The matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectra indicated an exclusive formation of cycles in the mass range of up to m/z 13,000 for Zr(acac)4 and up to m/z 18,000 for Bu2Sn(acac)2. Unusually high melting temperatures (187°C–192°C) were also achieved along with high crystallinities. Furthermore, four lactide/glycolide copolymerizations catalyzed by Zr(acac)4 were performed, and the topology and the extent of transesterification were characterized by MALDI‐TOF mass spectrometry and 13C NMR spectroscopy.
KW - MALDI-TOF MS
KW - Polycondensation
KW - Acetylacetonate
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639754
DO - https://doi.org/10.1002/pol.20250788
SN - 2642-4150
SP - 1
EP - 9
PB - Wiley Periodicals LLC.
AN - OPUS4-63975
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, Hans R.
A1 - Weidner, Steffen
T1 - Zwitterionic polymerization of glycolide catalyzed by pyridine
N2 - The usefulness of various N- and P-based catalysts for syntheses of cyclic polyglycolide via zwitterionic polymerization of glycolide was examined. Most catalysts produced discolored, largely insoluble polyglycolides consisting of cycles and unidentified byproducts. Soluble, cyclic polyglycolides were obtained using neat pyridine as catalyst at 120 °C, 100 °C, 80 °C, and even at 60 °C. The number-average molecular weights were extremely low and depended slightly on the glycolide-to-pyridine ratio. Three different mass distributions of the cycles were detected by mass spectrometry, depending on the reaction conditions. The cyclic polyglycolides were also characterized by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) measurements. The SAXS data in combination with the mass spectra indicate that the majority of the cycles form extended-ring crystallites
KW - MALDI-TOF MS
KW - Polylactide
KW - Polymerization
KW - Zitterions
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639748
DO - https://doi.org/10.1039/d5py00762c
SN - 1759-9954
SP - 1
EP - 9
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-63974
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 - Reaction order
KW - Activation energy
KW - Microstructure
KW - Quantum chemical calculation
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636840
DO - https://doi.org/10.1002/pi.6772
SN - 0959-8103
SP - 1
EP - 8
PB - Wiley
AN - OPUS4-63684
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fink, Friedrich
A1 - Stawski, Tomasz M.
A1 - Emmerling, Franziska
A1 - Falkenhagen, Jana
T1 - A novel machine-learning approach to unlock technical lignin classification by NIR spectroscopy - bench to handheld
N2 - In this research, the utilization of near-infrared (NIR) spectroscopy in conjunction with advanced machine learning methods is investigated for categorizing technical lignins obtained from different biomass sources and industrial procedures. Technical lignins, such as kraft, organosolv and lignosulfonates, have different chemical compositions, which continue to make uniform characterization and application in sustainable sectors extremely difficult. Fast, universally accessible analytics combined with data analysis is still an open question. For the first time three distinct NIR spectrometers—a high-performance benchtop system, a mid-priced compact device, and an economical handheld unit—were utilized to record NIR spectra of 31 unique lignin samples. The spectra underwent pre-processing through standard normal variate (SNV) transformation and Savitzky-Golay derivatives to amplify spectral features and decrease noise. Principal component analysis (PCA) was employed to reduce data complexity and extract crucial characteristics for classification purposes. Subsequently, four machine learning algorithms—Support Vector Machines (SVM), Gaussian Naive Bayes (GNB), Gaussian Process Classification (GPC), and Decision Tree Classification (DTC)—were implemented for the classification of the lignin samples. The DTC model exhibited the highest accuracy among them across different spectrometers. Although the benchtop spectrometer produced the most precise outcomes, the compact NeoSpectra system also displayed potential as a cost-efficient option. Nonetheless, the restricted spectral coverage of the handheld NIRONE spectrometer resulted in reduced classification accuracy. Our discoveries highlight the capability of NIR spectroscopy, combined with robust data analysis techniques, for the swift and non-destructive classification of technical lignins, facilitating their improved utilization in sustainable fields.
KW - Technical lignins
KW - NIR spectroscopy
KW - Classification
KW - Machine-learning
KW - PCA
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634518
DO - https://doi.org/10.1016/j.chemolab.2025.105467
SN - 0169-7439
VL - 264
SP - 1
EP - 10
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-63451
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, Hans R.
A1 - Weidner, Steffen
A1 - Meyer, A.
T1 - About Polycondensation, Disproportionation, and Cyclization of Acetylated Poly(L-Lactide) Esters
N2 - L-lactide (LA) is polymerized with ethyl L-lactate or trifluoroethanol as initiators (LA/In = 30/1), and the resulting poly(L-lactide) esters are acetylated with acetic anhydride. The acetylated PLA esters are mixed with SnOct2, dibutyltin bis(4-chlorophenoxide), or dibutyltin bis(pentafluorophenoxide) in solution and crystallized at 120 °C. The doped crystals are annealed at 140 °C or at 160 °C for 7, 14, and 28 days, and the chemical modifications that occurred in the solid state are monitored by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass spectrometry, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) measurements. All catalysts promoted polycondensation, while no significant formation of cycles is observed. However, in the presence of SnOct2, disproportionation of chains occurred upon annealing at 120 or 140 °C, and crystallites consisting of extended chains with Mn values ≈3500 – 3600 and low dispersities (Ð < 1.5) are formed.
KW - MALDI-TOF MS
KW - Polycondensation
KW - Polylactides
KW - Transesterifcation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630349
DO - https://doi.org/10.1002/macp.202400175
SN - 1521-3935
VL - 225
IS - 19
PB - Wiley VHC-Verlag
AN - OPUS4-63034
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dalgic, Mete‐Sungur
A1 - Kumar, Sourabh
A1 - Weidner, Steffen
T1 - Quantitative Analysis of Polymers by MALDI‐TOF Mass Spectrometry: Correlation Between Signal Intensity and Arm Number
N2 - The signal intensities of linear and star‐shaped poly(L‐lactides) (PLA) and poly (ethylene oxides) (PEO) were compared to determine the influence of the number of arms on the ionization in matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. In this study, a variety of blends were prepared and investigated, including binary and ternary combinations of linear and star‐shaped polymers with similar molecular masses. The focus was on examining their intensity ratios. In equimolar binary PLA blends, polymer stars were observed to exhibit higher intensities than their linear counterparts. This result was supported by experiments with equimolar ternary PLA blends, which clearly demonstrated an intensity dependence on the number of polymer arms. It was observed that four‐arm PLA exhibited higher intensities than three‐arm PLA. A similar trend was observed in investigations involving acetylated polymer end groups, suggesting that differences in ionization are primarily influenced by polymer architecture rather than end groups. In order to validate this assumption, the binding energies for [polymer‐K] + adduct ions utilizing the most stable geometry obtained from GOAT (Global Optimizer Algorithm) were calculated, revealing that star‐shaped lower mass oligomers have slightly higher binding energies.
KW - MALDI-TOF MS
KW - Starlike polymers
KW - Quantification
KW - Topology
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653401
DO - https://doi.org/10.1002/jms.70023
SN - 1076-5174
VL - 61
IS - 1
SP - 1
EP - 12
PB - John Wiley & Sons Ltd.
AN - OPUS4-65340
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weidner, Steffen
A1 - Meyer, Andreas
A1 - Falkenhagen, Jana
A1 - Kricheldorf, Hans R.
T1 - Cyclic polyglycolide by means of metal acetylacetonates
N2 - Glycolide was polymerized in bulk at 160 °C using various metal acetylacetonates as catalysts. Zirconium acetylacetonate was particularly efficient, enabling rapid polymerization even at 130 °C. The formation of cyclic poly(glycolic acid) (PGA), most likely via a ring-expansion polymerization (REP) mechanism, was proven by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Depending on the polymerization conditions, the formation of even-numbered cycles was favored to varying degrees. Number-average molecular weights (Mn) in the range of 2000–3500 g mol−1 were achieved with dispersities below 2.0. Wide-angle X-ray scattering (WAXS) powder patterns showed that the crystal lattice was the same as that of known linear PGAs, regardless of the Mn values. These patterns enabled a comparison of crystallinities with values derived from DSC measurements.
KW - MALDI-TOF MS
KW - Polyglycolide
KW - Crystallization
KW - Small-angle X-ray scattering
KW - Cyclization
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653731
DO - https://doi.org/10.1039/d5ra07961f
SN - 2046-2069
VL - 16
IS - 2
SP - 1757
EP - 1764
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - RPRT
A1 - Falkenhagen, Jana
A1 - Beskers, Timo. F.
A1 - Myxa, Anett
A1 - Pursch, Matthias
T1 - Round-robin test for size exclusion chromatography – Data summary
N2 - Size exclusion chromatography (SEC or GPC) is one critical component of polymer analysis to meet the increasing requirements in regulatory context – namely, determination of Mn, as well as oligomers of less than 500 g mol-1 and 1000 g mol-1. The underlying test methods (OECD 118/119 and DIN EN ISO 13885 1 to 3) provide a framework for SEC measurements; however, they lack sufficient specificity to obtain accurate results. Previous SEC round robin tests were mostly performed on homopolymers and did not collect data on oligomer contents.
A new round robin test was initiated and conceptualized within the Task force “Method Evaluation for Polymer REACh (MeEP)”, an initiative of “Industrieforum Analytik” within the German Chemical Society (GDCh). Samples for this study were selected to represent both easy benchmark polymers as well as real-life, industry-relevant polymer materials. Data collection focused on the regulatory requirements.
Distribution of samples, gathering of individual results and evaluation were carried out by BAM. A data summary as initial result is reported here. Further evaluation and interpretation are a part of ongoing research.
KW - Size exclusion chromatography
KW - Polymers
KW - Oligomer content
KW - Round-robin test
PY - 2026
DO - https://doi.org/10.26272/opus4-65587
SP - 1
EP - 84
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-65587
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Zengchao
A1 - Nirmalananthan-Budau, Nithiya
A1 - Resch-Genger, Ute
A1 - Panne, Ulrich
A1 - Weidner, Steffen
T1 - Separation of polystyrene nanoparticles bearing different carboxyl group densities and functional groups quantification with capillary electrophoresis and asymmetrical flow field flow fractionation
N2 - Two sets of polystyrene nanoparticles (PSNPs) with comparable core sizes but different carboxyl group densities were made and separated using asymmetric flow field flow fractionation (AF4), capillary electrophoresis (CE), and the off-line hyphenation of both methods. Our results revealed the significant potential of two-dimensional off-line AF4-CE hyphenation to improve the separation and demonstrated for the first time, the applicability of CE to determine the functional group density of nanoparticles (NPs). Compared to the result acquired with conductometric titration, the result obtained with synthesized 100 nm sized PSNPs revealed only a slight deviation of 1.7%. Commercial 100 nm sized PSNPs yielded a deviation of 4.6 %. For 60 nm sized PSNPs, a larger deviation of 10.6 % between both methods was observed, which is attributed to the lower separation resolution.
KW - Nanoparticle
KW - A4F
KW - Capillary electrophoresis
KW - Carboxyl group
PY - 2020
DO - https://doi.org/10.1016/j.chroma.2020.461392
VL - 1626
SP - 461392
PB - Elsevier B.V.
AN - OPUS4-51080
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Trimpin, Sarah
A1 - Yenchick, Frank S.
A1 - Lee, Chuping
A1 - Hoang, Khoa
A1 - Pophristic, Milan
A1 - Karki, Santosh
A1 - Marshall, Darrell D.
A1 - Lu, I-Chung
A1 - Lutomski, Corinne A.
A1 - El-Baba, Tarick J.
A1 - Wang, Beixi
A1 - Pagnotti, Vincent S.
A1 - Meher, Anil K.
A1 - Chakrabarty, Shubhashis
A1 - Imperial, Lorelei F.
A1 - Madarshahian, Sara
A1 - Richards, Alicia L.
A1 - Lietz, Christopher B.
A1 - Moreno-Pedraza, Abigail
A1 - Leach, Samantha M.
A1 - Gibson, Stephen C.
A1 - Elia, Efstathios A.
A1 - Thawoos, Shameemah M.
A1 - Woodall, Daniel W.
A1 - Jarois, Dean R.
A1 - Davis, Eric T.J.
A1 - Liao, Guochao
A1 - Muthunayake, Nisansala S.
A1 - Redding, McKenna J.
A1 - Reynolds, Christian A.
A1 - Anthony, Thilani M.
A1 - Vithanarachchi, Sashiprabha M.
A1 - DeMent, Paul
A1 - Adewale, Adeleye O.
A1 - Yan, Lu
A1 - Wager-Miller, James
A1 - Ahn, Young-Hoon
A1 - Sanderson, Thomas H.
A1 - Przyklenk, Karin
A1 - Greenberg, Miriam L.
A1 - Suits, Arthur G.
A1 - Allen, Matthew J.
A1 - Narayan, Srinivas B.
A1 - Caruso, Joseph A.
A1 - Stemmer, Paul M.
A1 - Nguyen, Hien M.
A1 - Weidner, Steffen
A1 - Rackers, Kevin J.
A1 - Djuric, Ana
A1 - Shulaev, Vladimir
A1 - Hendrickson, Tamara L.
A1 - Chow, Christine S.
A1 - Pflum, Mary Kay H.
A1 - Grayson, Scott M.
A1 - Lobodin, Vladislav V.
A1 - Guo, Zhongwu
A1 - Ni, Chi-Kung
A1 - Walker, J. Michael
A1 - Mackie, Ken
A1 - Inutan, Ellen D.
A1 - McEwen, Charles N.
T1 - New Processes for Ionizing Nonvolatile Compounds in Mass Spectrometry: The Road of Discovery to Current State-of-the-Art
N2 - This Perspective covers discovery and mechanistic aspects aswell as initial applications of novel ionization processes for use in massspectrometry that guided us in a series of subsequent discoveries, instrumentdevelopments, and commercialization. Vacuum matrix-assisted ionization onan intermediate pressure matrix-assisted laser desorption/ionization sourcewithout the use of a laser, high voltages, or any other added energy wassimply unbelievable, at first. Individually and as a whole, the variousdiscoveries and inventions started to paint, inter alia, an exciting new pictureand outlook in mass spectrometry from which key developments grew thatwere at the time unimaginable, and continue to surprise us in its simplisticpreeminence. We, and others, have demonstrated exceptional analyticalutility. Our current research is focused on how best to understand, improve, and use these novel ionization processes throughdedicated platforms and source developments. These ionization processes convert volatile and nonvolatile compounds from solid orliquid matrixes into gas-phase ions for analysis by mass spectrometry using, e.g., mass-selected fragmentation and ion mobilityspectrometry to provide accurate, and sometimes improved, mass and drift time resolution. The combination of research anddiscoveries demonstrated multiple advantages of the new ionization processes and established the basis of the successes that lead tothe Biemann Medal and this Perspective. How the new ionization processes relate to traditional ionization is also presented, as wellas how these technologies can be utilized in tandem through instrument modification and implementation to increase coverage ofcomplex materials through complementary strengths.
KW - Mass spectrometry
PY - 2024
DO - https://doi.org/10.1021/jasms.3c00122
SN - 1879-1123
VL - 35
IS - 12
SP - 2753
EP - 2784
PB - American Chemical Society (ACS)
AN - OPUS4-61417
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pollard, M.
T1 - Functionalized Poly(ethylene glycol)s (PEGs) as a Reference Material for Detection of Polymeric end Groups via SEC Hyphenated with FTIR and 1H-NMR (80 MHz)
N2 - With the online coupling (or hyphenation) of chemically-resolved spectroscopy detection with classical size-exclusion chromatography (SEC) it is possible to correlate polymer molecular size with chemical structure in a single in-situ or on-flow measurement. Medium-resolution 1H-NMR (60 MHz) spectroscopy (i.e., “desktop NMR”) and Fouriertransform Infrared Spectroscopy (FTIR) have both been developed as coupled methods (SEC-MR-NMR, SEC-FTIR) for the detection of polymer analytes by monitoring e.g. alkene or carbonyl functionality.1,2 Here, we have investigated the potential for the detection of polymer end groups, using a slightly higher field-strength spectrometer (80 MHz 1H Larmor frequency) and taking advantage of a columnless injection method that provides bulk spectra for reference. End-functionalized polymers were synthesized by reaction of PEG with toluene isocyanate, yielding ,-functionalized polymers with exactly 2 IR- and NMR-detectable functional groups per chain, as proven by MALD-TOF mass spectrometry. We have investigated the sensitivity (limit of detection) and spectral resolution for these functional groups in chloroform, THF, and water. Results have demonstrated a good feasibility for the simultaneous online detection of PEG backbone (M~4000 g/mol) and these end groups at the level of ca. 2 mol%.
T2 - 33rd International Symposium on Chromatography
CY - Budapest
DA - 18.09.2022
KW - Size exclusion chromatography
KW - Polyethyleneglycol
KW - MALDI-TOF MS
KW - NMR
PY - 2022
AN - OPUS4-56716
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kricheldorf, H. R.
T1 - Reversible Polycondensations and the Jacobson-Stockmayer Theory
N2 - Reversible polycondensations are polycondensations that include equilibration reactions at any stage of the process. Syntheses of Polyesters in bulk involving transesterification reactions and syntheses of polyamides in bulk involving transamidation are typical examples. In 1950, Jacobson and Stockmayer published a first theory of reversible polycondensations based on experimental studies with aliphatic polyesters.[1,2] They explained the reversibility by the reversible formation of cyclic oligomers and low molar mass polymers from an active chain end (so-called “back-biting”). The formation of cycles via end-to-end cyclization was excluded in agreement with Flory´s theory of irreversible polycondensations.[3] The reinvestigation of the Jacobson-Stockmayer experiments by the authors in combination with theoretical considerations shows that the JS theory is wrong. [4,5] It turned out that the experimental scenario is far from the reality. In real polycondensations, intermolecular equilibration is faster than “back-biting”, and end-to-end cyclization is quite normal. The revised theory of step-growth polymerization predicts that in the ideal case of 100% conversion, all reaction products are cycles, regardless, of whether the step-growth polymerization is reversible or not.
T2 - Polycondensation 2024
CY - Lyon, France
DA - 15.09.2024
KW - Polycondensation
KW - Cyclisation
KW - MALDI TOF MS
PY - 2024
UR - https://polycond-2024.sciencesconf.org/
AN - OPUS4-61070
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Jaeger, Carsten
T1 - Untargeted Analysis of Leachables Released from Recycled Polyethylene Canisters
N2 - Recycling existing materials and products as far as possible is an integral part of the circular economy. Plastic-based packaging, including containers for food and beverages but also for storing and transporting chemicals and dangerous goods, are presently made to a wide range from fossil resources. However, even for these “contact sensitive” products, there is still the aim of sustainability using recycled materials. For packings for the transport of dangerous goods, safety characteristics of the containments made from the “virgin” materials including polyethylene (PE) are well known and tested within the frame of their design type approval. Much less, however, is known about their counterparts made from recycled materials. Apart from material weaking, incorporation of residues into recycled plastics can cause contamination of the goods inside the packaging.
To fill this gap, we have evaluated high-density PE (HDPE) canisters made from post-consumer waste towards release of plastic additives and contaminants such as residues from former contents. Using a comprehensive untargeted high-resolution mass spectrometry (HRMS) approach as well as thermal extraction-desorption gas chromatography-mass spectrometry (TED-GC/MS), we detected up to 870 distinct components depending on the type of stored chemical and storage duration. Most of the components were unique to or released in significantly higher amounts from recycled HDPE compared to conventional HDPE. 129 of the components could be identified and analyzed for functional use. The analysis revealed “cosmetics”, “fragrance” and “flavoring” as major associations next to known and expected uses in the field of “plastics”, indicating significant introduction of foreign contaminants into the product. We present details on the compound classes involved and discuss consequences for political targets on increasing recycling rates in this product segment.
T2 - International Conference on Non-Target Screening
CY - Erding, Germany
DA - 13.10.2025
KW - Extractables
KW - Leachables
KW - Untargeted analysis
KW - Recycling
KW - Polyethylene
PY - 2025
AN - OPUS4-65742
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bayat, Mehmet Emin
A1 - Nandayapa, Edgar R.
A1 - Tiebe, Carlo
A1 - Unger, Eva L.
A1 - List-Kratochvil, Emil J. W.
T1 - An operando spectroscopic examination of the influence of trace humidity on interdigital back contact metal halide perovskite solar cells
N2 - Controlling trace humidity is vital for both the fabrication and long-term stability of metal halide perovskite (MHP) solar cells. Relevant humidity levels are typically below 10 ppmV, especially in glovebox-based processing and in well-encapsulated devices. Even minute amounts during fabrication can influence crystallization, introducing defects and lowering efficiency. Over time, humidity accelerates degradation of the perovskite layer and internal interfaces, ultimately reducing operational lifetime. Probing these effects at low concentrations under operando conditions is therefore essential for advancing device performance and durability. In this work, we employed a high-precision transfer standard dew point hygrometer to investigate humidity levels between 5 and 35 ppmV in non-encapsulated MHP solar cells. To permit unobstructed water migration during operation, we fabricated interdigital back contact devices. Operando measurements revealed water transport through the perovskite layer and enabled quantification of outgassing. Under trace-humidified conditions, devices exhibited initial charge-carrier quenching, followed by gradual recovery. Notably, the photocurrent response to humidified nitrogen demonstrated that the MHP layer behaves fully reversibly within the explored timescale and across the investigated humidity levels and conditions. These findings establish a systematic operando framework for examining extrinsic stressors in perovskites and highlight opportunities for assessing passivation strategies.
KW - Metal halide perovskite
KW - IBC solar cells
KW - In operando
KW - Extrinsic stressors
KW - Fabrication and encapsulation
KW - Trace humidity
KW - Two-site Stern-Volmer
KW - Charge-carrier quenching
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657560
DO - https://doi.org/10.1039/D6TA01295G
SP - 1
EP - 16
PB - The Royal Society of Chemistry
CY - London
AN - OPUS4-65756
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Bayat, Mehmet Emin
A1 - Nandayapa, Edgar R.
A1 - Tiebe, Carlo
A1 - Unger, Eva L.
A1 - List-Kratochvil, Emil J. W.
T1 - Raw data from: "An operando spectroscopic examination of the influence of trace humidity on interdigital back contact metal halide perovskite solar cells"
N2 - Controlling trace humidity is vital for both the fabrication and long-term stability of metal halide perovskite (MHP) solar cells. Relevant humidity levels are typically below 10 ppmV, especially in glovebox-based processing and in well-encapsulated devices. Even minute amounts during fabrication can influence crystallization, introducing defects and lowering efficiency. Over time, humidity accelerates degradation of the perovskite layer and internal interfaces, ultimately reducing operational lifetime. Probing these effects at low concentrations under operando conditions is therefore essential for advancing device performance and durability. In this work, we employed a high-precision transfer standard dew point hygrometer to investigate humidity levels between 5 and 35 ppmV in non-encapsulated MHP solar cells. To permit unobstructed water migration during operation, we fabricated interdigital back contact devices. Operando measurements revealed water transport through the perovskite layer and enabled quantification of outgassing. Under trace-humidified conditions, devices exhibited initial charge-carrier quenching, followed by gradual recovery. Notably, the photocurrent response to humidified nitrogen demonstrated that the MHP layer behaves fully reversibly within the explored timescale and across the investigated humidity levels and conditions. These findings establish a systematic operando framework for examining extrinsic stressors in perovskites and highlight opportunities for assessing passivation strategies.
KW - Metal halide perovskite
PY - 2026
DO - https://doi.org/10.5281/zenodo.18600851
PB - Zenodo
CY - Geneva
AN - OPUS4-65757
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Meier, F.
A1 - Drexel, R.
A1 - Wiesner, Yosri
A1 - Altmann, Korinna
A1 - Bartczak, D.
A1 - Alasonati, E.
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, 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.
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 complex matrices like mineral water and milk.
NanoPP was produced reproducibly in a top-down approach by crushing in acetone with an UltraTurrax, filtering and change of solvent to MilliQ water. The prepared nanoPP material was subjected to a comprehensive physicochemical characterization including e.g., DLS, PTA and AF4-MALS for particle size distribution assessment, PTA and SEM for particle number concentration determination, SEM and AFM for shape analysis and pyrolysis GC-MS for chemical identification. Performed studies showed that the prepared nanoPP material is irregularly shaped and highly polydisperse with a particle size of around 180 nm (e.g., Dh,z-ave from DLS) and a particle size distribution from around 15 nm up to 135 nm (radius of gyration Rg from AF4-MALS).
Storage stability studies using DLS, PTA and AF4-MALS revealed nanoPP in aqueous suspension to be stable for at least 22 months with respect to particle size distribution and number concentration rendering it a promising NP candidate reference material. However, conducted spiking experiments in mineral water and milk showed a time-dependent agglomeration of nanoPP that needs further investigation.
T2 - MICROPLASTICdays
CY - Ljubliana, Slovenia
DA - 03.02.2026
KW - Nanoplastics
KW - Reference materials
PY - 2026
AN - OPUS4-65769
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Meyer, Klas
T1 - Benchtop-NMR Spectroscopy as a PAT tool in industrial environments – Field integration of a laboratory instrument
N2 - Chemical industry is currently in a rapidly changing environment, e.g., due to variability of raw material quality, high energy costs and demand for improving efficiency. Process optimization and new process concepts become more and more important. Flexible chemical plants can produce various high-quality products using multi-purpose equipment with short downtimes between campaigns and reduce time to market for new products. Intensified continuous production plants allow for difficult to produce compounds like exothermic reactions with high heat dissipation.
Highly automated chemical process monitoring along with real-time quality control are prerequisites to such concepts and, thus, should be based on “real-time” chemical information. A commercially available benchtop NMR spectrometer was integrated to the full requirements of an automated chemical production environment such as explosion safety, field communication, and robust evaluation of sensor data. Field studies in modular and conventional production plant setups show promising results gaining process knowledge for further optimization. NMR spectroscopy appeared as powerful online analytical method and allows using a modular data analysis approach, which can even serve as reliable reference method for further calibration-dependent PAT applications (e.g., NIR or Raman spectroscopy).
Based on experiences from earlier field studies an enhanced field enclosure setup was developed and built, including the option of a secondary analytical method (e.g., optical spectroscopy). Integrated control systems allow for a flexible implementation based on the available automation infrastructure at the chemical plant or pilot plant setup. In the future, modular interconnecting “smart” PAT systems and process equipment have the potential speed up the setup of production equipment for chemicals and pharma-ceuticals and therefore help to reduce the time-to-market.
T2 - Analytica Conference 2026
CY - Munich, Germany
DA - 24.03.2026
KW - Benchtop NMR spectroscopy
KW - Process Analytical Technology
KW - Field integration
KW - Explosion safety
PY - 2026
AN - OPUS4-65771
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Meier, F.
A1 - Altmann, Korinna
T1 - Challenges in nanoplastic analysis: Reference materials, complex matrices, and limits of detection
N2 - The growing concern over nanoplastic particles (< 1 µm) in food and the environment has intensified the need for robust analytical approaches to detect, quantify, and characterize these particles. But the lack is high of standardized and well-characterized reference materials that reflect environmentally relevant nanoplastics according to:
• Size distribution
• Low abundance
• Chemical diversity
• Surface properties
• Behavior in complex matrices.
This poster shows different methods like FFF and AF4-MALS and their results when measuring a nanoPP reference materials candidate.
T2 - Analytica Conference 2026
CY - Munich, Germany
DA - 24.03.2026
KW - Nanoplastics
KW - Reference materials
KW - AF4-MALS
KW - FFF
PY - 2026
AN - OPUS4-65770
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -