TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter T1 - Calixarene in Photoresisten (Kopplung von flüssigchromatographischen Methoden mit der MALDI-TOF-MS) T2 - Fachgruppenvollversammlung BAM CY - Berlin, Deutschland DA - 2002-01-29 PY - 2002 AN - OPUS4-2191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falkenhagen, Jana A1 - Dietrich, P. T1 - New aspects concerning the stability of silica-based HPLC separation phases PY - 1994 SN - 0010-2164 VL - 24 SP - 11 EP - 16 PB - International Scientific Communications CY - Greens Farms, Conn. AN - OPUS4-2184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Schulz, Günter A1 - Heinemann, M. T1 - Methodenkopplung zur Polylactidcharakterisierung PY - 2003 SN - 0344-1733 SN - 1610-8256 VL - 27 SP - 56 EP - 57 PB - Vogel CY - Würzburg AN - OPUS4-2597 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 - GEN A1 - Mix, Renate A1 - Falkenhagen, Jana A1 - Schulze, Rolf-Dieter A1 - Gerstung, Vanessa A1 - Friedrich, Jörg Florian ED - K.L. Mittal, T1 - Plasma homo- and copolymerization of allyl alcohol and styrene KW - Plasma polymerization KW - Surface functionalization KW - Molar masses PY - 2009 SN - 978-90-04-16590-8 VL - 5 SP - 317 EP - 340 PB - Koninklijke Brill NV CY - Leiden, The Netherlands AN - OPUS4-19606 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 - 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 - JOUR A1 - Moser, Marko A1 - Behnke, Thomas A1 - Hamers-Allin, Carolina A1 - Klein-Hartwig, Karin A1 - Falkenhagen, Jana A1 - Resch-Genger, Ute T1 - Quantification of PEG-maleimide ligands and coupling efficiencies on nanoparticles with Ellman's reagent N2 - The surface modification of nanometer- and micrometer-sized particles and planar substrates with polyethylene glycol (PEG) ligands of varying length is a very common strategy to tune the hydrophilicity and biocompatibility of such materials, minimize unspecific interactions, improve biofunctionalization efficiencies, and enhance blood circulation times. Nevertheless, simple methods for the quantification of PEG ligands are comparatively rare. Here, we present a new concept for the quantification of PEG ligands for maleimide-functionalized PEG molecules and the determination of PEG coupling efficiencies, exploiting the quantitative reaction of maleimide with ʟ-cysteine, and the subsequent determination of the unreacted thiol with the photometric Ellman's test. This is shown for heterobifunctional PEG spacers of varying length and amino-functionalized polystyrene nanoparticles (PS NP) without and with differently charged encoding dyes. The reaction of ʟ-cysteine with the Ellman's reagent was monitored photometrically and with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) to derive the reaction mechanism and to obtain the stoichiometry factor for ʟ-cysteine quantification. Mass balances and quantification of ʟ-cysteine via its sulfur concentration using elemental analysis and inductively coupled plasma mass spectrometry (ICP-MS) confirmed the accuracy and reliability of this approach that can be extended to other surface groups and ligands. KW - Photometric assay KW - Surface analysis KW - Nanoparticle KW - Polyethylene glycol KW - PEG quantification KW - Ellman's test PY - 2015 DO - https://doi.org/10.1021/acs.analchem.5b02173 SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 18 SP - 9376 EP - 9383 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34468 LA - eng 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 - GEN A1 - Barner‐Kowollik, C. A1 - Falkenhagen, Jana A1 - Gründling, T. A1 - Weidner, Steffen ED - Barner-Kowollik, C. ED - Gründling, T. ED - Falkenhagen, Jana ED - Weidner, Steffen T1 - Introduction N2 - The book opens with an overview of the available mass analyzers. Special consideration is given by the authors Steven Blanksby and Gene Hart-Smith to their uses in polymer chemistry. Various ionization techniques applicable in polymer mass spectrometry are then explored in-depth by Anthony Gies. Chrys Wesdemiotis subsequently takes a close look at tandem mass spectrometry, a highly important tool for the elucidation of polymer structure and one of the major contemporary fields of development in the mass spectrometry sector. Sarah Trimpin and colleagues follow with their contribution, describing gas-phase ion-separation procedures as applied to synthetic polymers. The ionization process of polymers via the MALDI approach requires a careful design of the sample preparation procedures. Scott Hanton and Kevin Owens therefore provide a close look at how polymer samples are best prepared. Synthetic polymers are not only important materials in their own right, but are also frequently employed to (covalently) modify variable surfaces. Surface analysis is notoriously challenging and a range of techniques have to be employed to map the chemical characteristics of surface-bound macromolecules. Christine Mahoney and Steffen Weidner provide a detailed description of the part which surface-sensitive mass spectrometric techniques play in elucidating a polymer surface’s structure. Soft ionization mass spectrometry techniques can be especially powerful when combined with chromatographic techniques such as size exclusion chromatography (SEC), liquid adsorption chromatography at critical conditions (LACCCs) or both. Jana Falkenhagen and Steffen Weidner explore the wide variety of so-called hyphenated techniques and impressively demonstrate the information depth that can be attained by employing such technologies. While arguably the majority of molecular weight determination is carried out via SEC often equipped with refractive index as well as light scattering detectors, Till Gruendling, William Wallace, and colleagues demonstrate how MALDI-MS as well as SEC coupled to ESI-MS can be employed to deduce absolute molecular weight distributions. The chapter also provides an overview of contemporary automated data processing techniques for mass spectrometric data. Most polymers generated are arguably copolymers and it thus is mandatory to dedicate an entire chapter to the analysis of copolymers via mass spectrometry — Ulrich Schubert and Anna Crecelius provide an in-depth analysis. The field of living/controlled radical polymerization provides fascinating high precision avenues for the construction of complex macromolecular architectures and enables the generation of polymers with a high degree of end-group fidelity, which are often employed in cross-discipline applications (e.g., in biosynthetic conjugates). Soft ionization mass spectrometry plays an integral part in unravelling the mechanism of living/controlled radical polymerization processes as well as in the characterization of macromolecular building blocks: Christopher Barner-Kowollik and colleagues take a close look at the current state-of-the-art. Similarly, polymers generated via conventional radical polymerization can be readily investigated via mass spectrometry. Here, especially the investigation of the initiation process and of the generated end-group type is of high importance — Michael Buback, Greg Russell, and colleagues report. Finally, Grazyna Adamus and Marek Kowalczuk survey the field of mass spectrometry applied to polymers prepared via nonradical methods such as coordination polymerization, polycondensation, and polyaddition. The question of polymer stability and a detailed understanding of polymer degradation processes on a molecular level are of paramount importance for an evaluation of the performance of a polymer in chemical applications or as a material. Sabrina Carroccio and colleagues survey the field of soft ionization mass spectrometry applied to the molecular study of degradation processes at the book’s conclusion. KW - Mass spectrometry KW - Polymers PY - 2012 SN - 978-3-527-32924-3 SN - 978-3-527-64182-6 DO - https://doi.org/10.1002/9783527641826.ch SP - 1 EP - 4 PB - Wiley-VCH CY - Weinheim AN - OPUS4-65732 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 - JOUR A1 - Moser, Marko A1 - Schneider, Ralf A1 - Behnke, Thomas A1 - Schneider, Thomas A1 - Falkenhagen, Jana A1 - Resch-Genger, Ute T1 - Ellman’s and aldrithiol assay as versatile and complementary tools for the quantification of thiol groups and ligands on nanomaterials N2 - Simple, fast, and versatile methods for the quantification of thiol groups are of considerable interest not only for protein analysis but also for the characterization of the surface chemistry of nanomaterials stabilized with thiol ligands or bearing thiol groups for the subsequent (bio-) functionalization via maleimide−thiol chemistry. Here, we compare two simple colorimetric assays, the widely used Ellman’s assay performed at alkaline pH and the aldrithiol assay executed at acidic and neutral pH, with respect to their potential for the quantification of thiol groups and thiol ligands on different types of nanoparticles like polystyrene nanoparticles, semiconductor nanocrystals (SC NC), and noble metal particles, and we derive criteria for their use. In order to assess the underlying reaction mechanisms and to obtain stoichiometry factors mandatory for reliable thiol quantification, both methods were studied photometrically and with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), thereby demonstrating the influence of different thiols on the reaction mechanism. Our results underline the suitability of both methods for the quantification of directly accessible thiol groups or ligands on the surface of 2D- and 3D-supports, here exemplarily polystyrene nanoparticles. Moreover, we could derive strategies for the use of these simple assays for the determination of masked (i.e., not directly accessible) thiol groups like disulfides such as lipoic acid and thiol stabilizing ligands coordinatively bound to Cd and/or Hg surface atoms of II/VI and ternary SC NC and to gold and silver nanoparticles. KW - Nanoparticles KW - Ligands KW - Ellman KW - Aldrithiol KW - Quantification PY - 2016 DO - https://doi.org/10.1021/acs.analchem.6b01798 SN - 0003-2700 SN - 1520-6882 VL - 88 IS - 17 SP - 8624 EP - 8631 PB - ACS Publications CY - Washington AN - OPUS4-37561 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 - JOUR A1 - Schmid, C. A1 - Falkenhagen, Jana A1 - Barner-Kowollik, C. T1 - An efficient avenue to poly(styrene)-block-poly(Epsilon-caprolactone) polymers via switching from RAFT tio hydroxyl functionality: synthesis and characterization KW - 2D-liquid chromatography KW - End group transformation KW - LACCC-SEC KW - Reversible addition fragmentation chain transfer KW - Ring-opening polymerization KW - soft ionization mass spectrometry PY - 2011 DO - https://doi.org/10.1002/pola.24299 SN - 0360-6376 SN - 0887-624X VL - 49 IS - 1 SP - 1 EP - 10 PB - Wiley CY - Hoboken, NJ AN - OPUS4-22894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Much, Helmut A1 - Schulz, Günter T1 - Coupling of different modes of liquid chromatography of polymers with spectroscopic methods and MALDI-TOF-MS-key for determination of polymer heterogeneity T2 - 6th SPSJ International Polymer Conference (IPC 97) CY - Kusatsu, Japan DA - 1997-10-20 PY - 1997 VL - 6 AN - OPUS4-2233 LA - eng 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 - 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 - JOUR A1 - Chapartegui-Arias, Ander A1 - Villajos Collado, José Antonio A1 - Myxa, Anett A1 - Beyer, Sebastian A1 - Falkenhagen, Jana A1 - Schneider, Rudolf A1 - Emmerling, Franziska T1 - Covalently Fluorophore-Functionalized ZIF‑8 Colloidal Particles as a Sensing Platform for Endocrine-Disrupting Chemicals Such as Phthalates Plasticizers N2 - We present the optical sensing of phthalate Esters (PAEs), a group of endocrine-disrupting chemicals. The sensing takes place as changes in the fluorescence emission intensity of aminopyrene covalently bound to the organic ligands of the metal−organic framework compound ZIF-8. In the presence of PAEs, a quenching of the fluorescence emission is observed. We evaluated strategies to engineer colloidal size distribution of the sensing particles to optimize the sensory response to PAEs. A thorough characterization of the modified ZIF-8 nanoparticles included powder X-ray diffractometry, transmission electron microscopy, high-performance liquid chromatography, and photophysical characterization. The presented capability of the fluorophore-functionalized ZIF-8 to sense PAEs complements established methods such as chromatography-based procedures, which cannot be used on-site and paves the way for future developments such as hand-held quick sensing devices. KW - Sensing KW - MOF PY - 2019 DO - https://doi.org/10.1021/acsomega.9b01051 VL - 4 IS - 17 SP - 17090 EP - 17097 PB - ACS AN - OPUS4-49562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Ralph-Peter A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Schulz, Günter T1 - Charakterisierung von Si-Polymerarchitekturen durch Kopplung von flüssigchromatographischen Methoden mit der MALDI-TOF-Massenspektrometrie im DFG-Schwerpunktprogramm T2 - DFG-Kolloquium zum Schwerpunktprogramm "Silicium-Chemie" CY - Bielefeld, Deutschland DA - 1997-05-12 PY - 1997 AN - OPUS4-2231 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Krüger, Ralph-Peter A1 - Schulz, Günter A1 - Weidner, Steffen T1 - Polymer characterization by LC / MALDI-MS coupling T2 - Bayreuther Polymer Symposium 2001 CY - Bayreuth, Germany DA - 2001-09-16 PY - 2001 CY - Bayreuth AN - OPUS4-2256 LA - eng 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 - JOUR A1 - Mix, Renate A1 - Gerstung, Vanessa A1 - Falkenhagen, Jana A1 - Schulze, Rolf-Dieter A1 - Friedrich, Jörg Florian T1 - Characterization of plasma-polymerized allyl alcohol polymers and copolymers with styrene KW - Plasma polymerization KW - Surface functionalization KW - Molar mass PY - 2007 SN - 0169-4243 SN - 1568-5616 VL - 21 IS - 5-6 SP - 487 EP - 508 PB - VNU Science Press CY - Utrecht AN - OPUS4-14765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falkenhagen, Jana A1 - Much, Helmut A1 - Stauf, W. A1 - Müller, A. H. E. T1 - Characterization of block copolymers by liquid adsorption chromatography at critical conditions. 1. Diblock copolymers N2 - Liquid adsorption chromatography at critical conditions (LACCC) in normal and in reversed-phase modes provides independent information on the molar mass distributions of both blocks of poly(methyl methacrylate)-block-poly(tert-butyl methacrylate), even if no information about the precursor is available. In addition, the amount of unreacted precursor can be determined, even if its molar mass is comparable to that of the total block copolymer. The reversal of elution order by changing of stationary and mobile phases makes it possible to independently characterize each block in the SEC mode of the LACCC system. Thus, complete structural information is obtained even without using two-dimensional chromatographic techniques. PY - 2000 DO - https://doi.org/10.1021/ma991903j SN - 0024-9297 SN - 1520-5835 VL - 33 IS - 10 SP - 3687 EP - 3693 PB - American Chemical Society CY - Washington, DC AN - OPUS4-2172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -