TY - CONF A1 - Weidner, Steffen T1 - Multivariate statistics applied to MALDI-TOF MS data of pollen samples N2 - Pollen represent one major cause for human allergic diseases. Currently the characterization and identification of pollen is time-consuming since it mainly relies on the microscopic determination of the genus-specific pollen morphology. A variety of new analytical approaches, like Raman - and fluorescence spectroscopy have been proposed in order to develop fast and reliable pollen identification. Recently matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was initially applied for the rapid investigation of such complex biological samples. Taxonomic differences and relations of single pollen grains could be identified. Both commercially available lyophilized pollen and fresh pollen acquired from biological samples collected in parks and in the Botanical Garden Berlin in the years 2013-2015 were investigated. The samples were prepared by formic acid extraction in the gas phase and spotted with HCCA matrix. A variety of new approaches, like a newly developed MALDI target with micrometer sample spots sizes, were tested for their suitability. The obtained mass spectral data were investigated by principal component analysis (PCA). The applicability of MALDI-TOF mass spectrometry for the classification of pollen according to their taxonomic relationships was proven. Specifically, chemical differences in the mass spectra at the levels of plant order, genus and in many cases even of species could be identified. Based on these results, further investigations have been undertaken to optimize the sample preparation for the classification of single pollen grains in mixtures of pollens. A novel MALDI-target design was developed to enhance the phenotypic information of pollens in their mass spectra. The combination of mass spectral patterns and multivariate statistics provide a powerful tool for the investigation of structural correlations within mixtures. The results can be used to improve the reconstruction of taxonomic relations of single species in various mixtures and might be useful for the development of a fast routine method to identify pollen based on mass spectrometry. T2 - 64th ASMS Conference on Mass Spectrometry and Allied Topics CY - San Antonio, TX, USA DA - 05.06.2016 KW - Pollen KW - MALDI-TOF Mass Spectrometry KW - Multivariate statistics PY - 2016 AN - OPUS4-36837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baumann, Maria T1 - Characterization of poly(carbonate-dimethylsiloxane)-copolymers via LC, MALDI-TOF mass spectrometry and FTIR N2 - Copolymers made of polycarbonate (PC) and polydimethylsiloxane (PDMS) are broadly applied in material science. High impact-stability and transparency are the marks of bisphenol-A polycarbonate. PDMS on the other hand excels in thermal stability, flame resistance and weatherability. Combining those favourable characteristics in a copolymer yields in a ductile but impact-resistant and flame retardant material. In order to understand the synthesis process and to improve the quality and characteristics of a copolymer, knowing its structure is essential. The challenge lies in the variety of heterogeneities like molecular mass-, block-size- and block-distribution. This study addresses the structural characterization of PC-PDMS-copolymers using different liquid chromatographic techniques, including two dimensional combinations, hyphenated to MALDI-mass spectrometry and FTIR. The large difference in polarities of PC and PDMS is a challenge for liquid chromatography as well as ionization in MALDI. Nevertheless, we were able to differentiate between homopolymer and actual copolymer, clarify the presence of cyclic structures and gain information about the PDMS blocks T2 - SCM-8; International Symposium on the CY - Amsterdam, The Netherlands DA - 30.01.2017 KW - Copolymer characterization KW - Liquid chromatography KW - FTIR KW - MALDI-TOF-MS KW - LCCC PY - 2017 AN - OPUS4-39277 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lauer, Franziska T1 - A graphical user interface for a fast multivariate classification of MALDI-TOF MS data of pollen grains N2 - The common characterization and identification of pollen is a time-consuming task that mainly relies on microscopic determination of the genus-specific pollen morphology. A variety of spectroscopic and spectrometric approaches have been proposed to develop a fast and reliable pollen identification using specific molecular information. Amongst them, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) shows a high potential for the successful investigation of such complex biological samples. Based on optimized MALDI sample preparation using conductive carbon tape, the application of multivariate statistics (e.g. principal components analysis, PCA) yields an enormous improvement concerning taxonomic classification of pollen species compared to common microscopic techniques. Since multivariate evaluation of the recorded mass spectra is of vital importance for classification, it’s helpful to implement the applied sequence of standard Matlab functions into a graphical user interface (GUI). In this presentation, a stand-alone application (GUI) is shown, which provides multiple functions to perform fast multivariate analysis on multiple datasets. The use of a GUI enables a first overview on the measured dataset, conducts spectral pretreatment and can give classification information based on HCA and PCA evaluation. Moreover, it can be used to improve fast spectral classification and supports the development of a simple routine method to identify pollen based on mass spectrometry. T2 - 12. Interdisziplinäres Doktorandenseminar, GDCh AK Prozessanalytik CY - BAM, AH, Berlin, Germany DA - 25.03.2018 KW - MALDI KW - GUI KW - Pollen PY - 2018 AN - OPUS4-44661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Erste Ergebnisse der Strukturaufklärung von Siliciumpolymeren durch Kopplung von HPLC und MALDI-TOF-MS T2 - DFG-Kolloquium zum Schwerpunktprogramm "Silicium-Chemie" CY - Bielefeld, Germany DA - 1996-06-03 PY - 1996 AN - OPUS4-3747 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MassChrom2D - a software that combines chromatographic separation and mass spectrometric identification to analyze the composition of copolymers T2 - 60th ASMS Conference on Mass Spectrometry and Allied Topics CY - Vancouver, Canada DA - 2012-05-20 PY - 2012 AN - OPUS4-25954 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gugin, Nikita T1 - ZIF-8-Based Biocomposites via Reactive Extrusion: Towards Industrial-Scale Manufacturing N2 - Mechanochemistry offers a solvent-free, sustainable alternative to conventional synthesis of metal-organic framework (MOF) biocomposites, which hold great promise for applications in drug delivery, biocatalysis, and biosensing,[1] yet the field remains limited to batch-type, gram-scale processes that restrict industrial application. To overcome these limitations, we present a scalable solid-state method for producing MOF-based biocomposites via continuous reactive extrusion. The process begins with rapid model reactions using hand-mixing[2] to encapsulate a variety of biomolecules into zeolitic imidazolate framework-8 (ZIF-8), including proteins, carbohydrates, and enzymes, thereby enabling rapid screening and optimization of reaction conditions. The mild synthesis conditions preserve the catalytic activity of glucose oxidase, confirming the suitability of the method to sensitive biomaterials. Building on this, we translated the batch protocol to twin-screw extrusion,[3] enabling continuous and scalable synthesis of biocomposites such as bovine serum albumin (BSA)@ZIF-8 with tunable protein content. The extrusion process yielded highly crystalline, porous materials with protein loadings of up to 26 wt% and encapsulation efficiencies as high as 96%. The production rate reached 1.2 kg d⁻¹, significantly exceeding previously reported continuous methods.[4] To demonstrate the industrial viability of the method, we extended the approach to produce shaped ZIF-8 monoliths loaded with hyaluronic acid (HA) in a single-step extrusion. These monoliths retained their structural integrity during washing and released HA without measurable degradation, as confirmed by size-exclusion chromatography. Our study opens new avenues for the industrial implementation of MOF biocomposites and establishes reactive extrusion as a robust platform for their scalable synthesis and shaping, expanding the toolkit for drug delivery and biocatalytical applications. T2 - Tag der Chemie 2025 CY - Berlin, Germany DA - 03.07.2025 KW - Mechanochemistry PY - 2025 AN - OPUS4-63802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick T1 - Fraktionierung und Charakterisierung von Eisenoxid-Nanopartikeln mittels A4F-SAXS Online-Kopplung und Untersuchung der Zytotoxizität an Caco-2 Zellen T2 - 48. Wiss. Kongress der Deutschen Gesellschaft für Ernährung (DGE), Uni Potsdam CY - Potsdam, Germany DA - 2011-03-16 PY - 2011 AN - OPUS4-23597 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Hyphenated characterization techniques for polymer analysis: from SEC-ESI-MS to 2D HPLC/SEC chromatography T2 - Controlled/Living Radical Polymerizations: Latest Trends in Synthesis, Characterization and Industrial Applications CY - Houffalize, Belgium DA - 2009-09-17 PY - 2009 AN - OPUS4-20000 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - In Situ Characterization of Superparamagnetic Nanoparticles: Online Coupling of FFF and SAXS using Synchrotron Radiation T2 - Workshop on structural aspects of biocompatible ferrofluids: stabilization, properties control and application CY - Geesthacht, Germany DA - 2010-01-28 PY - 2010 AN - OPUS4-20100 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI-MS - supplementary to chromatographic techniques in characterizing chemical heterogeneity of oligomer ethylene terephthalates T2 - GdCH - Jahrestagung (Arbeitskreis Chromatographie) CY - Leipzig, Germany DA - 1995-11-06 PY - 1995 AN - OPUS4-11119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI-TOF Massenspektrometrie von Polymeren - Anwendungen, Probleme, Trends T2 - Kolloquium zum Thema "Untersuchungen von synthetischen bzw. Biopolymeren mit MALDI-TOF-MS" CY - Dresden, Germany DA - 2009-12-10 PY - 2009 AN - OPUS4-20151 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Sample spot heterogeneity investigated by MALDI-imaging mass spectrometry T2 - 18th International Mass Spectrometry Conference CY - Bremen, Germany DA - 2009-08-30 PY - 2009 AN - OPUS4-19989 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mix, Renate T1 - Analytical characterization of plasma polymers and copolymers of acrylic acid T2 - MACRO 2010 Polymer Science in the Service of Society CY - Glasgow, Scotland DA - 2010-07-11 PY - 2010 AN - OPUS4-21781 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Cyclic polylactides via ring-expansion polymerization N2 - We will report on a new kind of ring-expansion polymerization (REP) of cyclic esters based of three classes of catalysts. In contrast to REP described previously these new polymerizations are characterized by a self-extrusion of the catalysts resulting in cyclic homopolyesters as the only reaction product. These REP of L-lactide were performed in bulk at temperatures between 100 and 180°C without racemization. A simplified scheme of a REP catalyzed by BuCa or SnBi is presented below. With meso-lactide temperatures down to 60°C were realized. Depending on catalyst, time and temperature with equal quantities of even and odd-numbered cycles a strong predominance of either even or odd-numbered cycles was found. T2 - 255th ACS National Meeting CY - New Orleans, LA, USA DA - 18.03.2018 KW - MALDI-TOF MS KW - Poly(lactide) KW - Polymerisation KW - Catalysts PY - 2018 AN - OPUS4-44833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Beiträge zur Charakterisierung von synthetischen Si-Polymeren durch Kopplung von HPLC-Trennmethoden mit der MALDI-TOF-MS T2 - DFG-Symposium zum Schwerpunktprogramm "Silicium-Chemie" CY - Werfenweng, Austria DA - 2000-09-27 PY - 2000 AN - OPUS4-3350 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Characterization of silicon polymers by means of different liquid chromatographic modes and MALDI-TOF-MS T2 - DFG-Symposium zum Schwerpunktprogramm "Silicium-Chemie" CY - Werfenweng, Austria DA - 1998-06-11 PY - 1998 AN - OPUS4-2237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick T1 - Nanoparticle and Polymer Analysis using Synchrotron Radiation: Coupling Small-Angle Scattering and Field-Flow Fractionation T2 - 2nd Joint BERII and BESSY II Users Meeting CY - Berlin, Germany DA - 2010-12-09 PY - 2010 AN - OPUS4-22830 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI-TOF MS von ultra-hochmolekularen Polystyrolen mittels DCTB und Cäsium-Salzen T2 - 19. Kolloquium MALDI und Synthetische Polymere CY - Berlin DA - 2015-05-12 PY - 2015 AN - OPUS4-33055 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI-TOF Imaging Mass Spectrometry - an universal detector for copolymer chromatography T2 - ASMS-Conference on Mass Spectrometry CY - Denver, CO, USA DA - 2011-06-04 PY - 2011 AN - OPUS4-23732 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Charakterisierung der molekularen und chemischen Heterogenität von Polyoxymethylen (POM) T2 - BASF CY - Ludwigshafen am Rhein, Germany DA - 2005-06-17 PY - 2005 AN - OPUS4-11143 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Characterization of Polyesters and Copolyesters By Coupled Liquid Chromatographic and Spectroscopic Techniques T2 - Separation and Characterization of Natural and Synthetic Macromolecules (SCM-2) CY - Amsterdam, Netherlands DA - 2005-02-02 PY - 2005 AN - OPUS4-4342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Sample spot heterogeneity investigated by MALDI-imaging mass spectrometry T2 - 57th ASMS Conference On Mass Spectrometry and Allied Topics CY - Philadelphia, PA, USA DA - 2009-05-31 PY - 2009 AN - OPUS4-19191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - ^Mass spectrometry of synthetic polymers applications and limitations of the MALDI-TOF technique T2 - APST 2 (Advances in Polymer Science and Technology) CY - Linz, Austria DA - 2011-09-28 PY - 2011 AN - OPUS4-25271 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick T1 - A4F-SAXS Online Coupling in-situ Nanoparticles Analysis T2 - BfR-Seminar zum Thema Nanotoxikologie, Bundesinstitut für Risikobewertung CY - Berlin, Germany DA - 2010-08-04 PY - 2010 AN - OPUS4-21795 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knappe, Patrick T1 - A4F-SAXS Online Coupling - In-situ Nanoparticle Analysis T2 - BfR-Seminar zum Thema Nanotoxikologie CY - Berlin, Germany DA - 2010-08-04 PY - 2010 AN - OPUS4-21937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Mechanochemical conversion of polyethylene terephthalate into valuable metal-organic frameworks N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste is recycled globally. Here, we present a sustainable mechanochemical1 protocol for converting post-consumer polyethylene terephthalate (PET) textile and bottles into the porous metal-organic framework (MOF) UiO-66. We used time-resolved in situ synchrotron powder X-ray diffraction and Raman spectroscopy to monitor the depolymerization of PET during ball milling with sodium and potassium hydroxide and water as a liquid additive (Figure 1). For synthesizing UiO-66, we focused on the better performing sodium hydroxide and optimized two distinct synthetic routes to produce high-quality UiO-66. Our results demonstrate the potential of mechanochemistry to enable more circular MOF synthesis using post-consumer PET waste. T2 - The International Symposium on Mechanochemistry (Mech’cheM) 2025: New forces in Mechanochemistry CY - Montpellier, France DA - 04.06.2025 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2025 AN - OPUS4-63943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmid, C. T1 - Switching from raft to rop: A facile route to complex and sulfur-free macromolecular architectures T2 - 11th Annual UNESCO/IUPAC Workshop and Conference on Functional Polymeric Materials and Composites CY - Stellenbosch, South Africa DA - 2011-04-27 PY - 2011 AN - OPUS4-23981 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoskins, Jessica T1 - Liquid Chromatographic Separation and Mass Spectral Characterization of Randomly Branched Aliphatic Polyesters T2 - 60th ASMS Conference on Mass Spectrometry and Allied Topics CY - Vancouver, Canada DA - 2012-05-20 PY - 2012 AN - OPUS4-25956 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gabriel, Stefan T1 - Molmassenabhängige Verteilung einer Dried Droplet Probe in Abhängigkeit von Lösungsmitteln und Polymeren T2 - 16. Kolloquium MALDI und Synthetische Polymere CY - Berlin, Germany DA - 2012-05-08 PY - 2012 AN - OPUS4-26136 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gabriel, Stefan T1 - Seperation effects caused by dried-droplet sample preparation in MALDI mass spectrometry of polymers T2 - MACRO BeGE 2012 CY - Houffalize, Belgium DA - 2012-12-03 PY - 2012 AN - OPUS4-27603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thünemann, Andreas T1 - An X-ray view into the nano-world T2 - Workshop "Trends in Colloid and Interface Science TICI" CY - Potsdam, Germany DA - 2011-06-22 PY - 2011 AN - OPUS4-23978 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Characterization of co (polyamide)s N2 - Characterization problems of technically relevant copolyamides applying size exclusion chromatography, interaction chromatography and their combination with MALDI-TOF-MS will be discussed. T2 - 23. Kolloquium Massenspektrometrie und synthetische Polymere CY - Berlin, Germany DA - 14.05.2019 KW - LCCC KW - Mass spectrometry of polymers KW - SEC KW - LC / MALDI-TOF-MS coupling PY - 2019 AN - OPUS4-48221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Advances in characterization of polymer heterogeneity by coupling of chromatographic and spectroscopic methods T2 - International Discussion Meeting, Deutsche Bunsen-Gesellschaft für Physikalische Chemie CY - Mainz, Germany DA - 1999-03-15 PY - 1999 AN - OPUS4-3282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina T1 - Kopplung der Asymmetrischen Fluss-Feld-Fluss Fraktionierung mit der ICP-MS zur Analyse von Ag Nanopartikeln T2 - 24. ICPMS Anwendertreffen 2014 CY - Geesthacht DA - 2014-09-15 PY - 2014 AN - OPUS4-32004 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gabriel, Stefan T1 - MALDI-ToF-MS Imaging: Classical Dried Droplet vs. Ionic Matrix T2 - Advances in Polymer Science and Technology (APST) 3 CY - Linz, Austria DA - 2013-09-09 PY - 2013 AN - OPUS4-30165 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gabriel, Stefan T1 - Separation effects caused by the dried dropled sample preparation for MALDI-MS of synthetic polymers T2 - Adlershofer Forschungsforum 2013 CY - Berlin, Germany DA - 2013-11-12 PY - 2013 AN - OPUS4-30163 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Is Liquid Chromatography at Critical Conditions already a routine technique? T2 - Int. Symp. on GPC/SEC and Related Techniques CY - Frankfurt/Main DA - 2014-09-30 PY - 2014 AN - OPUS4-32000 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Charakterisierung von Polymeren durch Kombination von HPLC und MALDI-TOF-MS T2 - Statusseminar des ACA CY - Berlin, Germany DA - 1996-11-05 PY - 1996 AN - OPUS4-2228 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina T1 - Analysis of Silver Nanoparticles Using AF4 Coupled to ICP-MS: Investigating Sample Loss and Recovery Rates T2 - 10th International Conference on the Environmental Effects of Nanoparticles and Nanomaterials ICEENN 2015 CY - Vienna, Austria DA - 2015-09-06 PY - 2015 AN - OPUS4-34098 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina T1 - Analysis of Silver Nanoparticles Using AF4 Coupled to ICP-MS: Investigating Sample Loss and Recovery Rates T2 - 3rd Workshop on Field-Flow Fractionation - Mass Spectrometry CY - Vienna, Austria DA - 2015-09-05 PY - 2015 AN - OPUS4-34106 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Beiträge zur Charakterisierung von synthetischen Si-Polymeren durch Kopplung von HPLC-Trennmethoden mit der MALDI-TOF-MS T2 - InCom´01 CY - Düsseldorf, Germany DA - 2001-03-27 PY - 2001 AN - OPUS4-3351 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Charakterisierung von synthetischen Polymeren durch Kopplung flüssigchromato-graphischer Trennmethoden mit der MALDI-TOF-Massenspektrometrie T2 - 1. Berliner Werkstofftag CY - Berlin, Germany DA - 1999-09-16 PY - 1999 AN - OPUS4-3444 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Liquid Chromatography at Critical Conditions - advantages and shortcomings T2 - Arbeitskreis Polymeranalytik CY - Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF Darmstadt DA - 2015-03-20 PY - 2015 AN - OPUS4-32937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Characterization of polylactides by coupling of chromatographic methods with MALDI-TOF-MS T2 - ISPAC CY - Enschede, Netherlands DA - 2002-06-17 PY - 2002 AN - OPUS4-3454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Challenges of SEC and the necessity of round robin tests N2 - Size exclusion chromatography (SEC) is still the method of choice for determining the molar mass and molar mass distribution of macromolecules. It is a liquid chromatographic technique that separates molecules based on their size, respectively their hydrodynamic volume using a porous stationary phase that allows smaller molecules to pass through the pores while excluding larger molecules. The chromatogram from the size separation can be calibrated using polymers of known molar mass resulting in a relative molar mass distribution curve. From this distribution curve molar mass averages and the oligomer content (percentage of peak area smaller than 1000 g/mol and 500 g/mol) of polymers can be derived. The determination of oligomer content is important, because it is often used in regulatory contexts as a measure of small, mobile and potentially more toxic parts of the polymer. Polymer regulations are of increasing political and societal importance. Regulations often strive for narrow limits. But SEC has rather large error margins of 10-20% for the molar mass determination performed in different laboratories or on different instruments. These variances are well known to all experts and users and have been investigated in several round robin tests in the past. These resulted in DIN and ISO standards which, in our opinion, no longer meet today's requirements. Gaps have been identified that require further harmonization. Different polymer types or classes require different methods. On the other hand, as far as we know, the margins of error in determining oligomer content have not yet been investigated. It is expected that the variation will be rather high. This is because it depends on many factors related to the experimental conditions (column sets used, solvent, temperatures, sample preparation) on the one hand, and the data evaluation mechanisms (choice of baseline and peak limits) on the other. In order to actually measure the error margins and to support this with actual data a round robin test has been performed from June to November 2024 with approx. 40 participating laboratories. Three different solvents were selected, namely THF, DMAc or DMF and water. The samples were selected taking into account a wide range of practical aspects far from narrowly distributed standards: e.g higher distribution range, reduced solubility, included side components, copolymers and dispersions with gel content. In this contribution we will present the detailed concept of this round robin test and first impressions. T2 - 11th International Symposium on the Separation and Characterization of Natural and Synthetic Macromolecules CY - Amsterdam, Netherlands DA - 21.01.2025 KW - Size exclusion chromatography KW - Round robin tests PY - 2025 AN - OPUS4-62533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Error margins in the Determination of Molar Mass and Oligomer Content of Polymers N2 - Size exclusion chromatography (SEC) is still the method of choice for determining the molar mass and molar mass distribution of macromolecules. It is a liquid chromatographic technique that separates molecules based on their size, respectively their hydrodynamic volume using a porous stationary phase that allows smaller molecules to pass through the pores while excluding larger molecules. The chromatogram from the size separation can be calibrated using polymers of known molar mass resulting in a relative molar mass distribution curve. From this distribution curve molar mass averages and the oligomer content (percentage of peak area smaller than 1000 g/mol and 500 g/mol) of polymers can be derived. The determination of oligomer content is important, because it is often used in regulatory contexts as a measure of small, mobile and potentially more toxic parts of the polymer. Polymer regulations are of increasing political and social importance. Regulations often set very narrow limits. SEC has rather large error margins of 10-20% for the molar mass determination performed in different laboratories or on different instruments. These variances are well known to all experts and users and have been investigated in several round robin tests in the past. These resulted in DIN and ISO standards which, in our opinion, no longer meet today's requirements. As far as we know, the margins of error in determining oligomer content have not yet been investigated. It is expected that the variation will be rather high. This is because it depends on many factors related to the experimental conditions (column sets used, solvent, temperatures, sample preparation) on the one hand, and the data evaluation mechanisms (choice of baseline and peak limits) on the other. In order to actually measure the error margins and to support this with actual data a round robin test has been performed from June to November 2024 with approx. 40 participating laboratories. Three different solvents were selected, namely THF, DMAc or DMF and water. The samples were selected together with all the experts, taking into account a wide range of practical aspects far from narrowly distributed standards: e.g higher distribution range, reduced solubility, included side components, copolymers and dispersions with gel content. In this contribution we will present the detailed concept of this round robin test and first results. T2 - SETAC Europe 35th Annual Meeting CY - Vienna, Austria DA - 11.05.2025 KW - Size exclusion chromatography KW - REACH KW - Polymers KW - Round Robin Tests PY - 2025 AN - OPUS4-63307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - 30 years LC-MS of synthetic macromolecules – an old story or something left to discover? N2 - Structure elucidation of complex synthetic copolymers still represents a challenge. A one-dimensional separation technique cannot give the answer to the question: What are the molar mass distribution (MMD), the functionality distribution (FTD), the chemical composition distribution (CCD), the monomer sequence distribution (MSD), the topology differences within a single broad distributed polymer sample? Is the coupling of liquid chromatographic separation techniques to mass spectrometry able to fill the gaps to a certain degree? Different LC separation techniques as size exclusion chromatography (SEC), liquid adsorption chromatography (LAC), liquid chromatography at critical conditions (LCCC) and gradient elution liquid chromatography (GELC) combined with Matrix assisted Laser Desorption Ionization (MALDI) respectively Electrospray Ionization (ESI) Time of Flight (TOF) mass spectrometry are able to give information which otherwise are completely inaccessible. In some cases, CID tandem mass spectrometry is applied. Fragmentation of suitable precursor ions resulted in typical fragment ion patterns. This technique enables an additional information on e.g. sequences, structural defects and topology of complex polymer mixtures. Often the deficiencies of stand-alone methods can be bridged. LC, blind to structural information needs mass spectrometry as one of the most powerful detectors able to give detailed information on e.g. the repeat units, functionalization or copolymer composition of the chromatographic separated constituents. A separation prior to MS reduces radical the dispersity which is one of the reasons for failing of MS. Also problems with different ionization probabilities in complex mixtures can partly be overcame. The lecture will provide a series of examples where LC-MS has been applied to evaluate complex macromolecules and mixtures of these. On- and offline coupling principles will be compared and the pros and cons of both mass spectrometric techniques will be discussed. T2 - SCM-8; International Symposium on the CY - Amsterdam, The Netherlands DA - 30.01.2017 KW - Characterization of polymers KW - HPLC KW - UPLC/ESI-TOF-MS KW - LC/MALDI-TOF-MS KW - Coupling techniques PY - 2017 AN - OPUS4-39276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Nanoparticles separation using capillary electrophoresis N2 - Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important. A common method for nanoparticle separation, which was introduced in 1976 by Giddings, represents asymmetrical field-flow fractionation (AF4). It is a flow based separation method, which can be theoretically used to separate particles range from 1 nm to 50 µm. However, when the particles are smaller than 10 nm, separation with AF4 will become difficult to perform. Because in this case strong separation force, which induces aggregation of particles, should be applied. This will decrease recoveries of analytes and limit its application in accurate quantitative analysis. Capillary electrophoresis (CE) is another well-developed separation technique, in which samples will be separated in relation to their electrophoretic mobility. In recent years, CE has been used to separate different kinds of nanoparticles like, gold colloids or CdSe Quantum dots. However, till now only separation of particles smaller than 50 nm was reported. Because large size distribution of bigger particles will result in strong peak broadening and long separation time. A two-dimensional coupling of AF4 and CE might provide us a new separation method, which can extend the separation ranges of both methods and be a way to characterise particles with large size distributions. T2 - ESAS-CANAS Konferenz CY - Berlin, Germany DA - 21.03.2018 KW - Nanoparticles separation capillary electrophoresis asymmetrcial flow field flow fractionation PY - 2018 AN - OPUS4-47188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Beiträge zur Charakterisierung von synthetischen Si-Polymeren durch Kopplung von HPLC-Trennmethoden mit der MALDI-TOF-Massenspektrometrie T2 - Berliner Polymerentage 2000 CY - Berlin, Germany DA - 2000-10-09 PY - 2000 AN - OPUS4-3388 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Coupling techniques for copolymer characterization with focus on LC-MC T2 - ISPAC, 26th Int. Symposium on Polymer Analysis and Characterization CY - New Orleans, LA, USA DA - 2013-06-09 PY - 2013 AN - OPUS4-28631 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoskins, Jessica T1 - MALDI-TOF MS of Hyperbranched Polymers Aided by Liquid Chromatography Separation T2 - American Society for Mass Spectrometry Annual Conference 2013 CY - Minneapolis, MN, USA DA - 2013-06-08 PY - 2013 AN - OPUS4-28782 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sötebier, Carina T1 - Characterization of Ag nanoparticles: limitation and advantages of field-flow fractionation N2 - Silver nanoparticles (Ag NPs) are widely used in consumer products due to their excellent antibacterial properties. Their broad application has led to a variety of recent regulation on their use and labelling. Thus, a highly specific analytical method for their characterization and quantification is needed. Due to their large separation range, field-flow fractionation (FFF) techniques are repeatedly applied for the analysis of NP. Limitations of FFF include quantification, sample loss and insufficient recovery rates. Another challenge can be non-ideal elution behavior of particles in complex and unknown matrices. The possible sources for sample losses of Ag NP have been studied using an asymmetric flow FFF (AF4) in combination with inductively coupled plasma mass spectrometry (ICP-MS). The influence of different parameters, for example the sample concentration, on the recovery rates and sample loss has been investigated. Using laser ablation ICP-MS, the Ag deposition on the membrane was located and quantified. Our results identified ionic silver as the main sources of sample loss. These results can be useful for further method improvement. However, when a Ag NP sample containing an unknown complex matrix is analyzed, FFF method optimization is challenging as the sample might show a shift in the retention times and lower recovery rates. In this case, ICP-MS experiment in the single particle mode (sp-ICP-MS) can be a useful addition to the FFF measurement. Here, upon assumption of spherical particles, the geometric diameters can be calculated. This fast and easy approach can be helpful in order to interpret the FFF fractograms and advice the FFF method optimization process. T2 - 18th International Symposium on Field- and Flow-Based Separations CY - Dresden, Germany DA - 22.05.2016 KW - Silver KW - Nanoparticles KW - Field-flow fractionation KW - ICP-MS PY - 2016 AN - OPUS4-36352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeegers, G. P. T1 - Evidence for laser-induced redox reactions between added trifluoroacetate salts and substrate material during polystyrene/DCTB MALDI N2 - Polymers, such as polystyrene, have been successfully analyzed with matrix-assisted laser desorption/ionization (MALDI) through the addition of e.g. copper or silver salts. This method is often used to establish the polydispersity index of polymer blends. However, the mechanism of cation addition and the possible interactions between the added salts and the chosen target material are still points of interest. Therefore, the addition of several trifluoroacetate salts to a mixture of polystyrene and matrix on a range of different target plate materials was systematically investigated, revealing several new interesting aspects of MALDI. Polystyrene (Mw 1,920 Da) was mixed with a range of trifluoroacetate salts (Li, Na, K, Cs, Ba, Cr, Pd, Cu, Ag, Zn, Al and In, as well as trifluoroacetic acid) and analyzed with MALDI using 2 -[2E-3-4-tert-butylphenyl)- 2- methylprop-2-enylidene]ma lononitrile DCTB) as matrix on different target plate materials (chrome, copper, silver, gold, Ti90/Al6/V4, Inconel® 625, Zinc and stain less steel) to evaluate the occurrence of redox-reactions. Polystyrene/salt/matrix solutions were deposited through pneumatic-assisted spraying on microscope slide -shaped target plate insets of varying material, which, secured with copper tape, fitted a milled out structure from the original target plate. Spectra, obtained on a Bruker Autoflex I MALDI-Time -of-Flight mass spectrometer, were processed with MATLAB to obtain polystyrene-and matrix -adduct ion signal intensities for direct comparison between chosen conditions. The resulting spectra shed light on the MALDI adduct formation process and the cation-polystyrene interactions. It was found that the following cation -polystyrene adducts were formed on stainless steel: Al, Li, Na, Cu and Ag, where the yield was found to depend on the sample layer thickness and possibly the cation’s ability to form a complex with either one or two of polystyrene’s phenyl rings, based on the ligand-field and the valence bond theory. With the exception of Al, these salts also formed adducts and in case of Cu and Ag also sandwich adducts with DCTB. Some alkali salts (e.g. potassium) formed clusters rather than interacting with polystyrene or DCTB, which can be explained with the HSAB theory. Application of TFA salts on a copper surface led to copper cation formation, resulting in DCTB and polystyrene copper-adduct formation. The same effect occurred for silver substrate. In the absence of copper or silver salts, it is therefore still possible to form their respective adducts by choosing the proper alternative salt (e.g. Li, Cs, Ba, Cr) in combination with either a silver or a copper substrate surface. Incubation tests with copper beads in various salt solutions, before matrix and polystyrene addition, support that copper ions are not generated during the deposition process before the MALDI experiment is carried out, except when trifluoroacetic acid, indium and aluminium trifluoroacetate are used. For all other salts used on a copper plate, it can therefore be concluded that these copper cation forming redox-reactions are enabled by the input of laser photon energy. Furthermore, it was discovered that copper beads can successfully sequester polystyrene from the sample mixture, indicating the strong bonding of polystyrene to the copper surface. These findings support that the redox-reactions occur (almost) instantaneously with laser pulse impact at the sample-coated substrate surface. T2 - Jahrestagung der DGMS 2016 CY - Hamburg, Germany DA - 28.02.2016 KW - MALDI KW - Redox-reactions KW - Substrate KW - Cations PY - 2016 AN - OPUS4-36937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Synthesis of Polylactides and thier characterization by coupling of liquid chromatographic mathods with MALDI-TOF-MS T2 - 7th International Symposium on Polymers for Advanced Technologies CY - Fort Lauderdale, FL, USA DA - 2003-09-21 PY - 2003 AN - OPUS4-3542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Zur Chracterisierung von bioabbaubaren Polyestern durch Kopplung von chromatographischen Methoden mit der MALDI-Flugzeitmassenspektrometrie T2 - 11. Internationale Fachtagung Polymerwerkstoffe 2004 CY - Halle (Saale), Germany DA - 2004-09-29 PY - 2004 AN - OPUS4-3540 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Calixarene in Photoresisten (Kopplung von flüssigchromatographischen Methoden mit der MALDI-TOF-MS) T2 - Fachgruppenvollversammlung BAM CY - Berlin, Germany DA - 2002-01-29 PY - 2002 AN - OPUS4-3418 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Zur Synthese und Charakterisierung von Polylactiden T2 - Analytica Conference 2004 CY - Munich, Germany DA - 2004-05-11 PY - 2004 AN - OPUS4-3539 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Nanoparticles separation using capillary electrophoresis (CE) and asymmerical flow-field flow fractionation (AF4) N2 - Nowadays, different nanoparticles have been developed for commercial applications. However, since data on toxicity are barely available, their increasing application in cosmetic products, food and their release in the environment might cause severe problems. An accurate separation, identification and characterization of nanoparticles becomes increasingly important. A common method for nanoparticle separation, which was introduced in 1976 by Giddings, represents asymmetrical field-flow fractionation (AF4). It is a flow based separation method, which can be theoretically used to separate particles range from 1 nm to 50 µm. However, when the particles are smaller than 10 nm, separation with AF4 will become difficult to perform. Because in this case strong separation force, which induces aggregation of particles, should be applied. This will decrease recoveries of analytes and limit its application in accurate quantitative analysis. Capillary electrophoresis (CE) is another well-developed separation technique, in which samples will be separated in relation to their electrophoretic mobility. In recent years, CE has been used to separate different kinds of nanoparticles like, gold colloids or CdSe Quantum dots. However, till now only separation of particles smaller than 50 nm was reported. Because large size distribution of bigger particles will result in strong peak broadening and long separation time. A two-dimensional coupling of AF4 and CE might provide us a new separation method, which can extend the separation ranges of both methods and be a way to characterise particles with large size distributions. T2 - BAM PhD seminar CY - PhD seminar, Berlin, Germany DA - 22.06.2018 KW - Nanoparticles separation capillary electrophoresis asymmetrcial flow field flow fractionation PY - 2018 AN - OPUS4-47187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI-MS zur Aufklärung des Mechanismus der homogen katalysierten Polymerisation flüssigkristalliner Seitengruppenmethacrylate T2 - III. BAM-Kolloquium zu "Anwendung von MALDI-MS zur Charakterisierung von synthetischen Polymeren" CY - Berlin, Germany DA - 1999-05-17 PY - 1999 AN - OPUS4-11301 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Erste Untersuchungen zur Infrarot-MALDI-MS von Polymeren T2 - II. BAM-Kolloquium zu "Anwendung von MALDI-MS zur Charakterisierung von synthetischen Polymeren" CY - Berlin, Germany DA - 1998-05-04 PY - 1998 AN - OPUS4-11281 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Copolymer structure elucidation by multidimensional techniques with focus on UPLC x ESI-TOF-MS N2 - Structure elucidation of complex synthetic copolymers still represents a challenge. An one-dimensional separation technique cannot give the answer to the question: What are the molar mass distribution (MMD), the functionality distribution (FTD), the chemical composition distribution (CCD), the monomer sequence distribution (MSD), the topology differences within a single broad distributed polymer sample? Since the first LC/ ESI-MS experiment of the Nobel prize winner John B. Fenn in 1984, the coupling of liquid chromatographic to mass spectrometric techniques gained a continuous rapid development. Often the deficiencies of stand-alone methods can be bridged. LC, blind to structural information needs mass spectrometry as one of the most powerful detectors able to give detailed information on e.g. the repeat units, functionalization or copolymer composition of the chromatographic separated constituents. A separation prior to MS reduces radical the dispersity which is one of the reasons for failing of MS. Also problems with different ionization probabilities in complex mixtures can partly be overcame. Different LC separation techniques as size exclusion chromatography (SEC), liquid adsorption chromatography (LAC), liquid chromatography at critical conditions (LCCC) and gradient elution liquid chromatography (GELC) combined with Matrix assisted Laser Desorption Ionization (MALDI) respectively Electrospray Ionization (ESI) Time of Flight (TOF) mass spectrometry are able to give information which otherwise are completely inaccessible. In some cases CID tandem mass spectrometry is applied. Fragmentation of suitable precursor ions resulted in typical fragment ion patterns. This technique enables an additional information on e.g. sequences, structural defects and topology of complex polymer mixtures. Herein a new approach is demonstrated to provide evidence of different functionalities and short block sequences in statistical EO-PO copolymers. Furthermore silsesquioxane mixtures and Polyglycerols are investigated concerning occurring topology effects. T2 - 253rd ACS National Meeting CY - San Francisco, CA, USA DA - 02.04.2017 KW - Copolymer KW - Microstructure KW - Liquid chromatography KW - Mass spectrometry PY - 2017 AN - OPUS4-43372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Limitations of SEC: Strategies for Improved Regulatory Polymer Analysis N2 - Polymers, composed of repeating units called monomers, exhibit a diverse range of properties, with molecular weight distribution (MWD) being particularly important for regulatory risk assessments. Size exclusion chromatography (SEC), or gel permeation chromatography (GPC), is the primary technique for MWD characterization, as detailed in OECD guidelines 118 and 119, along with DIN and ISO standards. However, SEC faces significant shortcomings that complicate the accurate determination of MWD and oligomer content. These limitations include the insolubility of certain polymers, crosslinking, and ultra-high molecular weight characteristics, which can exceed SEC's separation capabilities. The presence of salts or modifiers can further interfere with oligomer content determination, and the availability of appropriate SEC columns and calibration standards limits comparability across laboratories. To enhance SEC's reliability and applicability within regulatory frameworks, innovative methods and strategies are essential. Proposed solutions involve new sample preparation techniques, advanced data interpretation methods, and the establishment of standardized methodologies to promote harmonization. This is especially crucial in light of the expected Polymer REACh (PREACh) legislation, which aims to regulate polymer registration and risk assessment within the European market. Given the anticipated complexity of the registration process, which requires extensive data generation, proactive strategies are needed to address SEC's challenges. Currently, there are no viable alternatives for oligomer content determination, and the unique properties of polymers often necessitate tailored analytical approaches. Without new methodologies and guidelines, the polymer registration process could become burdensome and costly, jeopardizing important products and markets in the EU. Key areas for improvement include extending existing norms to cover a broader range of solvents, addressing high error margins in oligomer content determination, establishing harmonized approaches for dealing with side components, and providing clarity on measuring partially soluble polymers. In conclusion, addressing SEC's limitations through the development of comprehensive guidelines and harmonization is critical for ensuring accurate and efficient polymer analysis, ultimately facilitating smoother registration processes. T2 - SETAC Europe 35th Annual Meeting CY - Vienna, Austria DA - 11.05.2025 KW - Size exclusion chromatography KW - Polymers KW - REACH PY - 2025 AN - OPUS4-63309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Upcycling waste PET bottles to porous UiO-66 by mechanochemistry N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste gets recycled globally. Most of it ends up in landfills or gets incinerated in a highly unsustainable manner. Here, I will present a sustainable mechanochemical protocol for the chemical upcycling of polyethylene terephthalate (PET) to porous UiO-66 metal-organic framework (MOF). In the first step, PET is ball-milled with sodium hydroxide and undergoes alkaline hydrolysis to disodium terephthalate (Na2TP). Time-resolved in situ monitoring of ball milling reaction by synchrotron powder X-ray diffraction shows the appearance of crystalline Na2TP after 20 min of milling. However, ex-situ analysis at different milling times by gel permeation chromatography reveals that the depolymerisation step needs more milling for completion. After two hours of ball milling, there are only trace amounts of leftover PET. For upcycling to UiO-66, a zirconium acetate cluster is added to Na2TP together with liquid additives and after milling for T2 - International Conference on Resource Chemistry 2024 CY - Alzenau, Germany DA - 13.03.2024 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2024 AN - OPUS4-62105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gollwitzer, Christian T1 - 3D printing material filled with metal organic frameworks analyzed by synchrotron based absorption edge tomography N2 - Absorption edge tomography, also known as differential tomography at absorption edges, is a method which exploits the sudden change of the attenuation coefficient, when the photon energy crosses the absorption edge of an element. Synchrotron radiation is the best source for absorption edge tomography, because of its small bandwidth, high intensity and easily adjustable photon energy. The synchrotron beamline BAMline at the synchrotron radiation facility BESSY II in Berlin, which is operated by the Bundesanstalt für Materialforschung und -prüfung (BAM), provides a monochromatized beam in a photon energy range from 5 keV up to 80 keV with a bandwidth of 2%, when the double multilayer monochromator is used. Together with the microtomography setup, this enables differential tomography with submicron resolution at the K edge of the elements from chromium up to the lanthanides, and up to uranium, when the L edges are used as well. In this work, metal organic frameworks (MOFs) embedded in polymer are characterized using differential tomography. MOFs are microporous structures of metal ions, coordinated by organic linker molecules, that can be used in a broad field of applications, especially in gas storage and catalysis. In this work, polymer embedded MOFs were extruded into filaments, which could be used for 3d-printing to profit from the specific properties of the MOFs in polymeric materials combined with the arbitrary shapes provided by 3d-printing. For the extrusion, different polymer classes like ABS, polyester- and polyetherurethanes, as well as different MOFs (ZIF-8, ZIF-67, HKUST-1) were used to create MOF containing filaments with a nominal diameter of 3.0 mm. Differential tomography at the edges of the Zn, Co, and Cu was then used to find the distribution of the corresponding MOF in the filament and to analyze the shape of the inclusions. T2 - MSE 2018 CY - Darmstadt, Germany DA - 26.09.2018 KW - Absorption edge KW - Tomography KW - Metal organic framework KW - Synchrotron PY - 2018 AN - OPUS4-46429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kricheldorf, H. R. T1 - Cyclic Polyesters via ROPPOC or REP N2 - Various catalysts and polycondensation mechanisms (ROPPOC/REP/ROP)were presented and discussed with regard to the Formation of cyclic and linear polylactides. It could be shown that depending on the structure of the catalyst even- and od numbered cyclics were selectively formed. These data were supported by various analytical techniques like MALDI-TOF mass spectrometry and Size Exclusion Chromatography. T2 - Polycondensation 2018 CY - Alexandria, VA, USA DA - 14.10.2018 KW - Polycondensation KW - MALDI-TOF MS KW - Ring-opening polymerization PY - 2018 AN - OPUS4-46340 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Beiträge zur Charakterisierung von synthetischen Si-Polymeren durch Kopplung von HPLC-Trennmethoden mit der MALDI-TOF-MS T2 - Analytica Conference 2000 CY - Munich, Germany DA - 2000-04-11 PY - 2000 AN - OPUS4-3349 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Panne, Ulrich T1 - Polymerwissenschaften@BAM - Sicherheit macht Märkte N2 - Die Bundesanstalt für Materialforschung und -prüfung (BAM) ist eine Ressortforschungseinrichtung, die zum Schutz von Mensch, Umwelt und Sachgüter, forscht, prüft und berät. Im Fokus aller Tätigkeiten in der Materialwissenschaft, der Werkstofftechnik und der Chemie steht dabei die technische Sicherheit von Produkten und Prozessen. Dazu werden Substanzen, Werkstoffe, Bauteile, Komponenten und Anlagen sowie natürliche und technische Systeme erforscht und auf sicheren Umgang oder Betrieb geprüft und bewertet. Schwerpunkt des Vortrages sind multimodale Polymeranalytik, nanoskalige Sensormaterialien und die Charakterisierung von technischen Eigenschaften von Polymeren sowie ihre Alterung und Umweltrelevanz. T2 - Institutsvortrag CY - Fraunhofer IAP, Potsdam, Germany DA - 18.05.2018 KW - Polymerwissenschaften PY - 2018 AN - OPUS4-45243 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - You, Zengchao T1 - Comparison of the separation performance of a conventional and a miniaturized AF4 channels N2 - Currently available separation channels for asymmetric flow field-flow fractionation (AF4), which results in long analysis time and solvent consumption, limits the application of AF4 in [1} the field of nanoparticle analysis . A miniaturized AF4 channel was introduced for the rapid analysis of different nanoparticle samples. UV-Vis-MALS provides the possibility to measure the particle size and molar mass and offers a powerful tool for the investigation of [2] separation performances of different AF4 channels . Our objective was to develop fast and reliable separation methods for both channels and enable a direct comparison by the corresponding chromatographic parameters. T2 - 2016 BfR PhD Retreat DA - 31.08.2016 KW - Nanoparticles separation asymetrical flow field flow fractionation PY - 2016 AN - OPUS4-47192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinemann, M. T1 - Influence of L-LactideAcidity on the Synthesis of Poly(L-Lactide) By Reactive Extrusion and Special Combined Analytical Concepts for the Characterization of Polylactides" T2 - International Union of Pure and Applied Chemistry (IUPAC), Macro 2004 CY - Paris, France DA - 2004-07-04 PY - 2004 AN - OPUS4-5097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Zur Charakerisierung von bioabbaubaren Polyestern durch Kopplung von chromatographischen Methoden mit der MALDI-Flugzeitmassenspektrometrie T2 - Polydays 2004 CY - Potsdam, Germany DA - 2004-10-04 PY - 2004 AN - OPUS4-5172 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Charakterisierung biologisch abbaubarer Homo- und Copolyester T2 - 19. Suttgarter Kunststoff-Kolloquium CY - Stuttgart, Germany DA - 2005-03-09 PY - 2005 AN - OPUS4-7127 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Friedrich, Jörg Florian T1 - Pulsed plasma initiated homo and copolimerisation - molar masses T2 - ISPC-16 CY - Taormina, Italy DA - 2003-06-22 PY - 2003 AN - OPUS4-4669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Untersuchung von plasmamodifizierten Polymeren mit speziellen Analysenmethoden T2 - Abteilungsseminar, BAM, Abt. VI CY - Berlin, Germany DA - 1996-05-02 PY - 1996 AN - OPUS4-6411 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter T1 - Zur Synthese und Characterisierung von Polylactiden T2 - Analytica Conference 2004 CY - Munich, Germany DA - 2004-05-11 PY - 2004 AN - OPUS4-5096 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epping, Ruben T1 - Characterization of small heterogeneities in polymers by analysis of UPLC/ESI-MS reconstructed ion chromatograms N2 - From simple molar mass disperse homopolymers over copolymers to functionalized, 3-dimensional structures containing various distributions, the complexity of polymeric materials has become more and more sophisticated in recent years. With applications in medicine, pharmacy, smart materials or for the semiconductor industry the requirements for the characterization have risen with the complexity of the used polymers. For each additional distribution, an additional dimension in analysis is needed. Small, often isobaric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector. Instead of a complicated, time consuming and/or expensive 2d-chromatography or ion mobility spectrometry (IMS) method, that also has its limitations, here a simple approach using size exclusion chromatography (SEC) coupled with electrospray ionization mass spectrometry (ESI) is proposed. We used SEC for the separation because unlike other separation modes the separation in this mode solely should occur due to the hydrodynamic volume with no interference of other interactions. This simplifies the interpretation and the above mentioned heterogeneities should show a slight difference in hydrodynamic volume. ESI mass spectrometry can offer more than an access to mass dependent information like MMD, end group masses or CCD in polymer analysis. The online coupling to SEC allows the analysis of reconstructed ion chromatograms (RIC) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities in microstructure or topology, that are otherwise inaccessible or accessible only by time consuming or expensive methods. Because these heterogeneities might vary with the molar mass, analysis of the whole MMD-Peak (here the total ion current (TIC)) would not lead to the desired information. The broadening of the chromatographic peaks in this case does not origin from the already well known band broadening factors in chromatography from diffusion. This band broadening is attributed to the nature and composition of the analyte itself. Surprisingly there is very little investigation into the peak width or peak shape due to analyte structure itself found in literature. It is also shown, that with proper calibration even quantitative information could be obtained. This method is suitable to detect small differences in e. g. branching, topology, monomer sequence or tacticity and could potentially be used in production control of oligomeric products or other routinely done analyses to quickly indicate deviations from set parameters. Based on a variety of examples we demonstrate the possibilities and limitations of this approach. T2 - HTC-15 CY - Cardiff, UK DA - 24.01.2018 KW - UPLC/ESI-MS KW - Reconstructed chromatograms KW - Polymer analysis KW - Microstructure PY - 2018 AN - OPUS4-44137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brirmi, N. T1 - Effect of the pendant groups on the biobased polymers obtained by click chemistry suitable for the removal of phenolic compounds from water N2 - Phenolic compounds constitute a widespread and important class of water pollutants that should be efficiently removed from wastewater because of their toxicity even at low concentrations. They are indeed discharged in the liquid effluents from various factories: chemical, petrochemical, paper, wood, metallurgy and cocking plants 1. Phenols are also found in the waste waters of agroindustrial processes like the olive oil mills, tomato processing and wine distilleries 2,3. These contaminants cause several health problems for humans and aquatic organisms 4. Therefore, numerous studies on the removal of polyphenols from wastewaters have been conducted and many techniques have been used. Among them, adsorption is considered to be the best effective and low cost method. In this context, we have focused our efforts on optimizing adsorption process by development of novel, low-cost adsorbents derived from biobased byproducts with high adsorptive capacity. The main aim of this study is to synthesize triazole-based poly(ether-pyridine)s as new synthetic adsorbent phases for the extraction of phenolic compounds from aqueous solutions. For this purpose, new fluoromonomers containing 1,2,3-triazole units were prepared by the Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction and then used for the elaboration of novel poly(ether-pyridine-triazole)s (PEPTs) by direct polycondensation with isosorbide and bisphenol A. Chemical structure of fluorinated pyridinic monomers as well as resulting polymers was confirmed by 1H and 19F NMR spectroscopic methods. The thermal behaviour of the obtained PEPTs was characterized using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Their uptake performance to eliminate organic compounds was determined using High Performance Liquid Chromatography (HPLC). T2 - 12. Journees maghreb-europe. Matériaux et Applications aux Dispositifs et Capteurs CY - Monastir, Tunisia DA - 08.11.2022 KW - Biobased polymers KW - Phenolic compounds KW - 1,2,3-triazole PY - 2022 AN - OPUS4-56287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - MALDI-TOF-MS for the determination of polymerization mechanisms of biodegradable polymers N2 - Eine neue Art einer Ring-Expansion Polymerization (REP) von zyklischen Polylaktiden mittels neuer Katalysatoren wird präsentiert. MALDI-TOF Massenspektrometrie und andere analytische Techniken wurden zur Aufklärung des Mechanismus eingesetzt. Dabei zeigte sich, dass im Gegensatz zu anderen REP, ausschließlich zyklische Polymere gebildet wurden. Diese stellen neue Kandidatenmaterialien für zukünftige neue CRM dar. T2 - 22. MALDI-Kolloquium CY - Berlin, Germany DA - 15.05.2018 KW - MALDI-TOF MS KW - Polylaktid KW - Zyklen PY - 2018 AN - OPUS4-44835 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lauer, Franziska T1 - Multivariate statistics applied to MALDI-TOF MS data of pollen samples N2 - A variety of new analytical approaches have been proposed in order to develop fast and reliable pollen identification using specific molecular information. The combination of the obtained patterns of pollen mass spectra (MADLI-TOF MS (Autoflex III, Bruker)) and multivariate statistics provide a powerful tool for the investigation of structural correlations within pollen grain mixtures. Both commercially available lyophilized pollen (Sigma, Germany) and fresh pollen acquired from biological samples collected in parks and in the Botanic Garden Berlin-Dahlem, were utilized. The samples were extracted based on a modified biotyper protocol (Bruker) by formic acid extraction in the gas phase and spotted with HCCA matrix. This presentation show results from the newly developed MALDI target setup, with conductive tape. The spectral data were investigated by principal component analysis (PCA). T2 - 20. MALDI-Kolloquium CY - BAM Adlershof, Berlin, Germany DA - 10.05.2016 KW - MALDI-TOF Mass Spectrometry; Multivariate statistics; Pollen PY - 2016 AN - OPUS4-36842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lauer, Franziska T1 - Multivariate analysis of MALDI imaging mass spectrometry data of mixtures of single pollen grains N2 - Here, we present an advanced approach to identify pollen grains in mixtures based on: - a simplified sample preparation procedure - MALDI imaging mass spectrometry - chemometric tools Our goals are to: - explore the biomolecular variations in pollen - determine species-specific peak patterns - discriminate and identify single pollen grains in mixtures using MSI T2 - 66th Conference on Mass Spectrometry and Allied Topics CY - San Diego, CA, USA DA - 03.06.2018 KW - Pollen PY - 2018 AN - OPUS4-45196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Characterization of co (polyamide)s N2 - Charactrization of Co(polyamide)s Molar mass distribution; Functionalization; supression of end group effects in favor of sequence distribution analysis; Evidence of of randomization with increasing reaction time T2 - Polyamide Meeting, DSM CY - Sittard, The Netherlands DA - 20.04.2018 KW - Liquid chromatography KW - Mass spectrometry of polymers PY - 2018 AN - OPUS4-44747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Girod, Matthias T1 - Online characterization of silver nanoparticles from continuous synthesis with scattering methods T2 - SAS2012 CY - Sydney, Australia DA - 2012-11-19 PY - 2012 AN - OPUS4-27187 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Elert, Anna Maria T1 - Challenges in Microplastics identification is one Detection method enough? N2 - Long-term accumulation and fragmentation of plastic waste in ecosystems is currently a global subject of scientific and social concern. The combination of mechanical abrasion with degradation by UV radiation, and oxidation leads to the formation of small plastic particles (size less than 5 mm) which are not only distributed in oceanic and costal water, but also in sediments and terrestrial compartment. Since the contamination of the environment with plastic particles became emerging issue, an increasing trend towards investigating and controlling the MP pollution of the environment can be observed worldwide. Nonetheless, the reliable methodology that would facilitate and automate the monitoring of MP is still missing. Aiming at the selection of practical and standardized methods we present here a critical comparison of two vibrational spectroscopies, Raman and Fourier transform infrared (FTIR) spectroscopy, and two extraction methods: thermal desorption gas chromatography mass spectrometry (TED-GC-MS) and liquid extraction with subsequent size exclusion chromatography (SEC) using a soil (reference material) with known contents of PE, PP, PS and PET. The results are compared in terms of the measurements time, technique handling, detection limits and requirement for sample preparation. The comparison of Raman and FTIR spectra provides broader understanding of the polymeric origin of the analysed particles. Furthermore, at the level of individual particle, Raman imaging yields additional information on the stage of the polymer degradation and contamination on the surface. On the other hand, by applying the thermal and liquid extraction methods the fast and quantitative analysis of MP content is possible. Therefore, to establish reliable, standardized detection methods a combination of several parallel approaches should be considered. T2 - ICCE 2017 CY - Oslo, Norway DA - 18.06.2017 KW - Microplastics KW - TED-GC-MS KW - Vibrational Spectroscopy PY - 2017 AN - OPUS4-40942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Simple method for the quantification of PEG ligands and guidelines to the spectroscopic characterization of upconversion nanoparticles N2 - The surface modification of nanometer- and micrometer-sized particles with polyethylene glycol (PEG) ligands of varying length is a very common strategy to tune their hydrophilicity and biocompatibility, minimize unspecific interactions, improve biofunctionalization efficiencies, and enhance blood circulation times. Nevertheless, simple methods for the quantification of PEG ligands are rare. This is similarly true for the spectroscopic characterization of lanthanide-doped upconverting nanoparticles (UCNPs), novel near infrared (NIR)-excitable nonlinear fluorescence reporters for bioanalysis and theranostics, providing background-free multiple narrow emission bands in the visible and NIR, excellent photostability, and long luminescence lifetimes. We present here a simple method for the determination of the number of PEG ligands on nanomaterials and screening methods for the fast identification of nonradiative deaction pathways in UCNPs. T2 - SPIE Photonics West CY - San Francisco, CA, USA DA - 15.02.2016 KW - Optical assay KW - Fluorescence KW - Integrating sphere spectroscopy KW - Quantum yield KW - NIR KW - IR KW - Optical spectroscopy KW - Nanomaterials KW - Semiconducor nanocrystals KW - Upconversion nanocrystals KW - Surface analysis; KW - Ligand analysis PY - 2016 AN - OPUS4-35951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epping, Ruben T1 - Characterization of statistical EO-PO copolymers containing different end groups by UPLC/ESI-MS N2 - Commercial statistical ethylene oxide (EO) and propylene oxide (PO) copolymers of different monomer compositions and different average molar masses were studied by liquid chromatography under critical conditions (LCCC). Theoretical predictions of the existence of a critical adsorption point (CPA) for statistical copolymers with a given chemical and sequence distribution, could be studied and confirmed. An improved way to determine these critical conditions in a copolymer, alongside the inevitable chemical composition distribution (CCD), with the aid of mass spectrometric detection is described. Shift of the critical eluent composition with the monomer composition of the polymers could be observed. Due to the relatively low average molecular weight, broad molecular weight distribution (MWD) and the presumed existence of different end group functionalities as well as sequence distribution, gradient separation only by CCD was not possible. Therefore isocratic separations at the CPA of definite CCD’s were applied. Although the various present distributions partly superimposed the separation process the goal of separation by end group functionality could still be achieved on the basis of the additional dimension of ESI-MS. The existence of HO-H besides the desired AllylO-H end group functionalities could be confirmed and their amount could be estimated. T2 - International Symposium GPC/SEC and Related Techniques CY - Amsterdam, The Netherlands DA - 26.09.2016 KW - Polymers KW - UPLC KW - ESI-TOF-MS PY - 2016 AN - OPUS4-37632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lauer, Franziska T1 - Multivariate statistics applied to MALDI-TOF MS data of pollen samples N2 - Current pollen screening information networks are based on time-consuming, microscopic determination of the genus-specific pollen morphology. Additionally, the given information relies on prediction of plant growth, wind direction and seasonal information. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was introduced for rapid analysis of complex biological samples. MALDI-TOF provides the possibility to measure species-specific mass peak patterns of pollen and offers a powerful tool for investigation of taxonomic relations. Our objective is to develop a fast, reliable, routine method for detecting single pollen grains in pollen mixtures. The obtained spectra are analyzed by multivariate statistics. T2 - 49. Jahrestagung der Deutschen Gesellschaft für Massenspektrometrie CY - Hamburg DA - 28.02.2016 KW - Pollen KW - Datenanalyse KW - Hauptkomponentenanalyse PY - 2016 AN - OPUS4-35523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - LC-MS Coupling of synthetic polymers - 30 years after John B. Fenn T2 - Int. Symp. on the Sep. and Charact. of Natural and Synthetic Macromolecules (SCM-7) CY - Amsterdam, The Netherlands DA - 2015-01-27 PY - 2015 AN - OPUS4-32503 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Developments in Copolymer Characterization by chromatographic and spectroscopic techniques T2 - Pregl Colloquium at the National Institute of Chemistry, Slovenia CY - Ljubljana, Slovenia DA - 2013-10-16 PY - 2013 AN - OPUS4-29328 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mülow, Ulrike T1 - Transformation des Herbizids Metamitron in Modellsystemen: Identifizierung von Produkten und Bestimmung von Abbauraten T2 - Anakon 2015 CY - Graz, Austria DA - 2015-03-23 PY - 2015 AN - OPUS4-33547 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weidner, Steffen T1 - Improved analysis of ultra-high mass polymers in MALDI-TOF mass spectrometry T2 - ASMS 2015 CY - St. Louis (USA) DA - 2015-05-30 PY - 2015 AN - OPUS4-33446 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Polymer Characterization by Multidimensional Techniques T2 - Analysis and Characterization of Polymers CY - Toulouse, France DA - 2015-09-07 PY - 2015 AN - OPUS4-34108 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Biobased and biogegradable polymers: Analytical challenges N2 - The variability and heterogeneity in their structural composition is significant for nearly all synthetic and natural polymers. Beside molar mass also functionality type distribution, copolymer composition distribution and architectural features are responsible for changing the material properties. A wide range of analytical techniques are available to get insight into these parameters. However, in most cases it is essential to combine different sophisticated techniques to get closer to actual structures and to avoid statistical averages. Different liquid chromatographic separation modes and their coupling in a two-dimensional way (SEC, LCCC, HILIC, 2D-LC) in combination with suitable detection techniques (e.g. UV, RI, LS, IR, MALDI/ESI-MS) as well as techniques like BET, DCS, SEM/TEM were applied to make structural features visible. A few aspects are discussed for structural different polylactides from various synthesis routes and their behavior in LC-MS. Moreover, some analytical results for technical lignins valorized by mechanochemical treatment or modified by functional polymers are presented. T2 - 10th Intern. Symp. on the Separation and Characterisation of Natural and Synthetic Macromolecules (SCM-10) CY - Amsterdam, Netherlands DA - 01.02.2023 KW - Poly(lactides) KW - Technical lignin PY - 2023 AN - OPUS4-57002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Biobased and biodegradable Polymers: Analytical Challenges N2 - The variability and heterogeneity in their structural composition is significant for nearly all synthetic and natural polymers. Beside molar mass also functionality type distribution, copolymer composition distribution and architectural features are responsible for changing the material properties. A wide range of analytical techniques are available to get insight into these parameters. However, in most cases it is essential to combine different sophisticated techniques to get closer to actual structures and to avoid statistical averages. Different liquid chromatographic separation modes and their coupling in a two-dimensional way (SEC, LCCC, HILIC, 2D-LC) in combination with suitable detection techniques (e.g. UV, RI, LS, IR, MALDI/ESI-MS) as well as techniques like BET, DCS, SEM/TEM were applied to make structural features visible. A few aspects are discussed for structural different polylactides from various synthesis routes and their behavior in LC-MS. T2 - 34th International Symposium on Polymer Analysis and Characterization (ISPAC) CY - Stellenbosch, South Africa DA - 24.04.2023 KW - Biobased polymers KW - Biodegradable polymers KW - Analytical techniques PY - 2023 AN - OPUS4-60002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - A Tribute to Harald –Lignin as biobased polymer-Trends and analytical issues N2 - The presentation includes aspects of material design and characterization with a focus on lignin. Examples are the structural elucidation of lignosulfonates by means of two-dimensional chromatography, the mechanochemical degradation and functionalization of Kraft-Lignin with accompanying analytics. Future projects involving the incorporation of lignin into polymers will be presented. T2 - Farewell Symposium for Prof. Harald Pasch; Polymer Analysis: Advancements in Characterization and Quantification CY - Teltow, Germany DA - 18.03.2024 KW - Lignin KW - Biobased polymers PY - 2024 AN - OPUS4-60003 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 - Pollack, 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 - Benchtop 1H-NMR and FTIR have both been successfully developed for size-exclusion chromatography (SEC) applications. The latest implementations of these methods by Wilhelm and collaborators[1-3] have taken advantage of commerically available low-cost equipment, and a provide a means to obtain slice-by-slice spectra for the monitoring of functional groups in polymer separations. Demonstrated applications include the detection of highly diluted chains in a polymer blend (e.g., PS/PMMA), copolymer content determination (e.g., styrene-methyl methacrylate), and butadiene isomer detection. To synthesize and characterize an end-labelled low molecular wt. poly(ethylene glycol) as a model polymer to aid in the development and validation of spectroscopic detection (FTIR and 1H-NMR) for SEC applications. A particular focus is to improve quantitation and/or detection of highly diluted funtional groups (e.g., polymer chain ends or sparsely functionalized chains) In the first approach, an isocyanate with IR- and NMR-active functional groups was reacted with PEG (4000 and 10000 g/mol) to form end-functionalized chains by means of an addition reaction. The functionalization of the 10000 g/mol PEG was found to be non-homogeneous (not discussed further). The 4000 g/mol PEG was successfully functionalized to 100%, found to be homogeneous across the molecular weight distribution and could therefore serve as a model polymer for analysis by the coupled methods. T2 - 10th International Symposium on the Separation and Charcterization of Natural and Synthetic Macromolecules CY - Amsterdam, Netherlands DA - 01.02.2023 KW - PEG KW - Reference materials KW - NMR KW - MALDI-TOF MS PY - 2023 AN - OPUS4-57071 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 - Fink, Friedrich A1 - Falkenhagen, Jana T1 - From bench to mini – Classification of technical lignins with NIR N2 - Lignin, a by-product of the pulp and paper industry, is the second most abundant biopolymer but remains underutilized due to its complex structure and variability in biomass origin. Classification based on biomass source is crucial for quality assurance and application predictability. This study employs near-infrared (NIR) spectroscopy to classify technical lignins from softwoods, hardwoods, straw, and grasses. Machine learning models (ML), including Support Vector Machines (SVM), Gaussian Process Classification (GPC), Gaussian Naive Bayes (GNB), and Decision Tree Classification (DTC), were developed using spectral preprocessing and principle component analysis (PCA). The models were compared with spectra from handheld and compact spectrometers. Results highlight the potential of NIR spectroscopy and machine learning to enable rapid, reliable lignin classification, paving the way for improved industrial utilization of this abundant resource. T2 - 11th International Symposium on the Separation and Characterization of Natural and Synthetic Macromolecules CY - Amsterdam, The Netherlands DA - 21.01.2025 KW - Lignin KW - Classification KW - Near infrared spectroscopy PY - 2025 AN - OPUS4-62531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Waste to value: upcycling PET bottles into MOFs using mechanochemistry N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste gets recycled globally. Most of it ends up in landfills or gets incinerated in a highly unsustainable manner. Here, I will present a sustainable mechanochemical protocol for the chemical upcycling of waste polyethylene terephthalate (PET) bottles to porous UiO-66 metal-organic framework (MOF). We used in situ and ex situ characterization to gain a deep understanding of the underlying mechanochemical process leading to high crystallinity and -porosity UiO-66. Our results show the potential of mechanochemistry for the sustainable production of high-quality value-added materials such as UiO-66 from waste PET bottles. T2 - 2024 Green Chemistry Gordon Research Conference CY - Barcelona, Spain DA - 31.07.2024 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2024 AN - OPUS4-62107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - View into the Depths of Copolymer Microstructure N2 - For different kinds of polymers it will be shown how it could be realized to obtain information on small, sometimes isomeric topological heterogeneities by coupling UPLC / ESI-TOF-MS and LC /MALDI-TOF-MS. T2 - DSM, Fall Meeting CY - Breda, The Netherlands DA - 07.11.2019 KW - Microstructure KW - LC-MS KW - Copolymer PY - 2019 AN - OPUS4-49587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Well defined liquid crystalline homo and block copolymerthacrylates synthesized by organolanthanide complexes T2 - Europolymer Conference 1999 (EUPOC '99) Regular Macromolecular Structures Based on the Controlled Polymerization Processes CY - Gargnano, Italy DA - 1999-05-23 PY - 1999 AN - OPUS4-11310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Synthesis and Characterization of Polyhedral Silsesquioxanes with Nanotubular Structures T2 - DFG-Schwerpunktprogramm "Nanodrähte und Nanoröhren" CY - Bad Honnef, Germany DA - 2004-04-23 PY - 2004 AN - OPUS4-5095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -