TY - JOUR
A1 - Hodoroaba, Vasile-Dan
A1 - Hoffmann, V.
A1 - Steers, E.B.M.
A1 - Griepentrog, Michael
A1 - Dück, Alexander
A1 - Beck, Uwe
T1 - Round Robin exercise: Coated materials for glow discharge spectroscopy
N2 - A Round Robin (RR) exercise on selected coated materials has been carried out with the aim of finding the optimal conditions for the analysis of nitride layers with GD-OES. Such pre-normative work is necessary for the evaluation of parallel development of the production of nitride layers as certified reference materials (CRMs). Two types of samples, TiN layer and VN layer, respectively, with chemical compositions close to stoichiometry and a thickness of ~3 µm, deposited on a steel substrate, have been provided to the RR participants. Additionally, another type of sample, a (100 nm CrNi/100 nm Cu) multilayer (ML) stack deposited on silicon wafer has also been included in the RR. This sample can be used as a CRM for checking GD spectrometer conditions and it has been proved helpful in further development of GDS instrumentation and methodology. The RR exercise has been performed in the frame of the EC Thematic Network on Glow Discharge Spectroscopy for Spectrochemical Analysis (GDS-Net).
KW - Coated/Layered Reference Materials
KW - Nitrides
KW - Multilayer
KW - GDS
KW - Round Robin
PY - 2006
DO - https://doi.org/10.1039/B513426A
SN - 0267-9477
SN - 1364-5544
VL - 21
IS - 1
SP - 74
EP - 81
PB - Royal Society of Chemistry
CY - London
AN - OPUS4-11762
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hodoroaba, Vasile-Dan
A1 - Unger, Wolfgang
A1 - Jenett, H.
A1 - Hoffmann, V.
A1 - Hagenhoff, B.
A1 - Kayser, S.
A1 - Wetzig, K.
T1 - Depth profiling of electrically non-conductive layered samples by RF-GDOES and HFM plasma SNMS
N2 - The work is intended to compare the capabilities of two similar depth profiling techniques to analyse electrically non-conductive samples. In order to get a better evaluation of the depth resolution, various multilayer sandwiches, such as SiO2/TiO2 and Si3N4/SiO2 deposited on glass substrates have been investigated. Optimised depth profiles are presented for both methods, glow discharge optical emission spectrometry (GDOES) and radiofrequency mode (known as HFM in the SNMS literature) of plasma secondary neutral mass spectrometry (SNMS). The optimisation procedure, necessary to get the best set of plasma parameters, which result in the optimal depth resolution, is also described for one selected sample. Additionally, sputtering crater profilometry was carried out in order to check out the flatness of the sputtered crater. The influence of the thickness of the sample substrate on the sputtering rate is discussed. Finally, advantages and disadvantages of the use of these two depth profiling methods, especially for the non-conductive samples, are concluded from this comparative study. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis of a cross-sectioned sample was carried out in order to get supplementary information.
KW - rf-Glow discharge
KW - HFM plasma SNMS
KW - Non-conductive layered samples
KW - Depth resolution
KW - Crater shape
KW - ToF-SIMS
PY - 2001
DO - https://doi.org/10.1016/S0169-4332(01)00259-8
SN - 0169-4332
SN - 1873-5584
VL - 179
IS - 1-4
SP - 30
EP - 37
PB - North-Holland
CY - Amsterdam
AN - OPUS4-6882
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hodoroaba, Vasile-Dan
A1 - Hoffmann, V.
A1 - Steers, E. B. M.
A1 - Wetzig, K.
T1 - Exploitation of the effect of hydrogen on an analytical glow discharge
T2 - Winter Conference on Plasma Spectrochemistry 2002
CY - Scottsdale, AZ, USA
DA - 2002-01-06
PY - 2002
SN - 0161-6951
SP - 261
EP - 262
PB - ICP Information Newsletter, Inc.
CY - Amherst, Mass.
AN - OPUS4-1589
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bruna, F. G.
A1 - Prokop, M.
A1 - Bystron, T.
A1 - Loukrakpam, R.
A1 - Melke, J.
A1 - Lobo, C. M. S.
A1 - Fink, M.
A1 - Zhu, M.
A1 - Voloshina, E.
A1 - Kutter, M.
A1 - Hoffmann, H.
A1 - Yusenko, Kirill
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, B.
A1 - Bouzek, K.
A1 - Paulus, B.
A1 - Roth, C.
T1 - Following adsorbed intermediates on a platinum gas diffusion electrode in H3PO3‑containing electrolytes using in situ X‑ray absorption spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalyst with H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - Δμ XANES
KW - H3PO3
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - ACS
CY - Washington, DC
AN - OPUS4-55815
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Sittner, Jonathan
A1 - Hoffmann, T.
A1 - Bertmer, M.
A1 - Neubert, M.
A1 - Schuster, T.
A1 - Gluth, Gregor
ED - Rogge, Andreas
ED - Meng, Birgit
T1 - Optimizing calcination methods towards a more sustainable production of calcined clays
N2 - Calcined clays are emerging as sustainable alternatives for cement production due to their potential to reduce carbon footprint and energy consumption. This study investigates the calcination of low-grade kaolinitic clays, using rotary kiln and fluidized bed. The calcined clays from the rotary kiln showed enhanced performance in the cement paste. The fluidized bed method demonstrated the potential for significant energy savings, achieving near-complete dehydroxylation with just 30 minutes of calcination. These findings highlight the promise of fluidized bed calcination for efficient clay activation, though further optimization is needed.
T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building
CY - Berlin, Germany
DA - 16.10.2024
KW - Calcination methods
KW - Optimizing
KW - Blended cement pastes
KW - XRD results
KW - Thermogravimetric analysis (TGA)
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612891
SN - 978-3-9818564-7-7
SP - 37
EP - 45
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-61289
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - INPR
A1 - Glauber, J.-P.
A1 - Lorenz, J.
A1 - Liu, J.
A1 - Seifert, M.
A1 - Hoffmann, V.
A1 - Abad Andrade, Carlos Enrique
A1 - Rogalla, D.
A1 - Harms, C.
A1 - Wark, M.
A1 - Nolan, M.
A1 - Devi, A.
T1 - High Quality Crystalline VN Thin Films via MOCVD from a New Vanadium Precursor: Linking Growth Chemistry to Functional Catalytic Surfaces
N2 - Vanadium nitride (VN) has been identified as a promising material for numerous applications including electrochemical nitrogen reduction reaction (eNRR). For such applications, catalyst nanoengineering will help to experimentally test its theoretically predicted eNRR activity, but the majority of investigated VN catalysts are prepared by fabrication methods that do not allow for nanoengineering to the required degree. Herein, we report on a new metalorganic chemical vapor deposition (MOCVD) process for the growth of high quality, facetted and crystalline VN thin films relevant for eNRR applications. N,N’-diisopropylformamidinato [V(dpfamd)3] was identified as a promising precursor as it possesses favorable thermal properties relevant for MOCVD. The application of [V(dpfamd)3] in a MOCVD process with NH3 as co-reactant yielded crystalline VN thin films on Si substrates with high compositional purity. With the potential of using the catalytic activity of VN towards eNRR, the structure-property correlation is of relevance and in this context, the thin films were subjected to complementary analysis including X-ray diffraction (XRD), Rutherford backscattering spectrometry in combination with nuclear reaction analysis (RBS/NRA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Based on the observation of the significant influence NH3 has on the growth characteristics, we conducted first principles density functional theory (DFT) simulations of the precursor reactivity in the absence and presence of NH3 towards VN, supporting experimental findings of energetically more favorable decomposition of [V(dpfamd)3] to VN in the presence of NH3. Process transfer from Si to conductive Ti substrates, relevant for prospective electrochemical testing, revealed comparable VN thin film properties rendering these films promising for further investigation of eNRR applications in follow up studies.
KW - Metal nitrades
KW - MOCVD
KW - Nitrogen reduction reaction
KW - Precursors
KW - DFT
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648600
DO - https://doi.org/10.26434/chemrxiv-2025-1t4gq
SP - 1
EP - 25
AN - OPUS4-64860
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Weimann, Karin
A1 - Hoffmann, C.
T1 - Ressourceneffizienz im Betonrecycling - Rahmen und Möglichkeiten in Deutschland und der Schweiz
N2 - Aufgrund der großen anfallenden Massenströme ist die Wiederverwertung von Baurestmassen in Industrienationen von besonderer Bedeutung. Auch vor dem Hintergrund der Ressourceneffizienz wird beispielsweise die Nutzung des in Bauschutt vorhandenen Wertstoffpotentials zunehmend wichtiger.
Eine besondere Rolle spielt dabei die Wiederverwertung von Altbeton. Ein Grund hierfür ist der deutliche Anstieg des seit Mitte des letzten Jahrhunderts im Bauwesen verbrauchten Betons und die damit verbundene – zeitlich versetzte – Zunahme des Altbetonanteils im Bauschutt. Darüber hinaus ist das Wertstoffpotential von Altbeton im Vergleich zu anderen Abbruchmaterialien besonders groß, denn Altbeton kann unter bestimmten Bedingungen sehr hochwertig auch als rezyklierte Gesteinskörnung wieder in der Betonherstellung eingesetzt werden. Damit kann ein Kreislauf im Sinne eines Closed-loop-Recycling verwirklicht und Altbeton damit hochwertig wiederverwertet werden.
T2 - R13 - Fachtagung Recycling
CY - Weimar, Germany
DA - 19.09.2013
KW - Ressourceneffizienz
KW - Beton
KW - Recycling
KW - Ökobilanzielle Betrachtung
PY - 2013
IS - Paper 14
SP - 1
EP - 11
PB - Bauhaus-Univ.
CY - Weimar
AN - OPUS4-30061
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gomes, Bruna F.
A1 - Prokop, Martin
A1 - Bystron, Tomas
A1 - Loukrakpam, Rameshwori
A1 - Melke, Julia
A1 - Lobo, Carlos M. S.
A1 - Fink, Michael
A1 - Zhu, Mengshu
A1 - Voloshina, Elena
A1 - Kutter, Maximilian
A1 - Hoffmann, Hendrik
A1 - Yusenko, Kirill V.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, Bettina
A1 - Bouzek, Karel
A1 - Paulus, Beate
A1 - Roth, Christina
T1 - Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using In Situ X-ray Absorption Spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalystwith H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate Proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - H3PO3,
KW - Δμ XANES
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - American Chemical Society (ACS)
AN - OPUS4-64733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bui, M.
A1 - Hoffmann, K. F.
A1 - Braun, T.
A1 - Riedel, S.
A1 - Heinekamp, Christian
A1 - Scheurell, K.
A1 - Scholz, G.
A1 - Stawski, Tomasz
A1 - Emmerling, Franziska
T1 - An Amorphous Teflate Doped Aluminium Chlorofluoride:
A Solid Lewis-Superacid for the Dehydrofluorination of
Fluoroalkanes
N2 - Ananion-dopedaluminiumchlorofluoride AlCl0.1F2.8(OTeF5)0.1(ACF-teflate) was synthesized.The material contains pentafluor-oorthotellurate(teflate)groups, which mimic fluoride ions electronically, but are sterically more demanding. They are embedded into the amorphous structure. The latter was studied by PDF analysis, EXAFS data and MAS NMR spectroscopy. The mesoporous powder is a Lewis superacid, and ATR-IR spectra of adsorbed CD3CN reveal a blue-shift of the adsorption band by73 cm-1, which is larger than the shift for SbF5. Remarkably,ACF-teflate catalyzes dehydrofluorination reactions of mono-fluoroalkanes to yield olefins in C6D6. In these cases,no Friedel-Crafts products were formed.
KW - Aluminium fluorides
KW - Aluminium teflates
KW - C-F bond activation
KW - Lewis superacids
KW - Silanes
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572290
DO - https://doi.org/10.1002/cctc.202300350
SN - 1867-3880
SP - 1
EP - 7
PB - Wiley VHC-Verlag
AN - OPUS4-57229
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Abbas, Ioana M.
A1 - Vranic, M.
A1 - Hoffmann, Holger
A1 - El-Khatib, Ahmed H.
A1 - Montes-Bayón, M.
A1 - Möller, H. M.
A1 - Weller, Michael G.
T1 - Investigations of the copper peptide hepcidin-25 by LC-MS/MS and NMR (+)
N2 - Hepcidin-25 was identified as the main iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II)-binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1% ammonia. Further, mass spectrometry (tandem mass spectrometry (MS/MS), high-resolution mass spectrometry HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D)model of hepcidin-25with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or reference material comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.
KW - Metalloprotein
KW - Peptide
KW - Chromatography
KW - High pH
KW - Mobile phase
KW - Metrology
KW - Purity
KW - Reference material
KW - ATCUN
KW - Copper
KW - Nickel
PY - 2018
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-457796
UR - http://www.mdpi.com/1422-0067/19/8/2271
DO - https://doi.org/10.3390/ijms19082271
SN - 1422-0067
VL - 19
IS - 8
SP - 2271, 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-45779
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Abbas, Ioana M.
A1 - Hoffmann, Holger
A1 - Montes-Bayón, M.
A1 - Weller, Michael G.
T1 - Improved LC-MS/MS method for the quantification of hepcidin-25 in clinical samples
N2 - Mass spectrometry-based methods play a crucial role in the quantification of the main iron metabolism regulator hepcidin by singling out the bioactive 25-residue peptide from the other naturally occurring N-truncated isoforms (hepcidin-20, -22, -24), which seem to be inactive in iron homeostasis. However, several difficulties arise in the MS analysis of hepcidin due to the sticky character of the peptide and the lack of suitable standards. Here, we propose the use of amino- and fluoro-silanized autosampler vials to reduce hepcidin interaction to laboratory glassware surfaces after testing several types of vials for the preparation of stock solutions and serum samples for isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS). Furthermore, we have investigated two sample preparation strategies and two chromatographic separation conditions with the aim of developing an LC-MS/MS method for the sensitive and reliable quantification of hepcidin-25 in serum samples. A chromatographic separation based on usual acidic mobile phases was compared with a novel approach involving the separation of hepcidin-25 with solvents at high pH containing 0.1% of ammonia. Both methods were applied to clinical samples in an intra-laboratory comparison of two LC-MS/MS methods using the same hepcidin-25 calibrators with good correlation of the results. Finally, we recommend an LC-MS/MS-based quantification method with a dynamic range of 0.5–40 μg/L for the assessment of hepcidin-25 in human serum that uses TFA-based mobile phases and silanized glass vials.
KW - HPLC
KW - Liquid chromatography
KW - Mass spectrometry
KW - Silanization
KW - Mobile phase
KW - Adsorption
KW - Peptide losses
KW - Recovery
KW - Validation
KW - Quality control
KW - QC
KW - Iron disorders
KW - Chronic kidney disease
KW - Metrology
KW - Round robin exercise
KW - Basic solvent
KW - Peptide analysis
PY - 2018
DO - https://doi.org/10.1007/s00216-018-1056-0
SN - 1618-2642
SN - 1618-2650
VL - 410
IS - 16
SP - 3835
EP - 3846
PB - Springer Nature
CY - Heidelberg
AN - OPUS4-45053
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Descalzo López, Ana Belén
A1 - Xu, H.-J.
A1 - Xue, Z.-L.
A1 - Hoffmann, Katrin
A1 - Shen, Z.
A1 - Weller, Michael G.
A1 - You, X.-Z.
A1 - Rurack, Knut
T1 - Phenanthrene-Fused Boron-Dipyrromethenes as Bright Long-Wavelength Fluorophores
N2 - A new class of boron-dipyrromethene (BDP or BODIPY) dyes was obtained by phenanthrene fusion to the β-pyrrole positions, absorbing in the wavelength range of important laser sources. Despite a 'propeller-like' distorted structure in the crystalline state, the chromophore absorbs (log ε ≥ 5) and fluoresces (Φf ≥ 0.8) strongly and can be easily turned into a fluorescence light-up probe. Incorporation into latex beads produces bright and photostable single-dye and Förster Resonance Energy Transfer (FRET) particles for microscopy applications.
KW - Fluoreszenz
KW - Absorption
KW - BODIPY-Farbstoffe
KW - Ladungstransfer
KW - NIR-Farbstoffe
PY - 2008
DO - https://doi.org/10.1021/ol800271e
SN - 1523-7060
SN - 1523-7052
VL - 10
IS - 8
SP - 1581
EP - 1584
PB - American Chemical Society
CY - Washington, DC
AN - OPUS4-17511
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wiesner, Yosri
A1 - Hoffmann, Thomas
A1 - Range, David
A1 - Altmann, Korinna
T1 - Microplastics in sediments of the river Rhine—A workflow for preparation and analysis of sediment samples from aquatic river systems for monitoring purposes
N2 - AbstractMicroplastics (MP) can be detected in all environmental systems. Marine and terrestrial aquatic systems, especially the transported suspended solids, have often been the focus of scientific investigations in the past. Sediments of aquatic river systems, on the other hand, were often ignored due to the time‐consuming sample preparation and analysis procedures. Spectroscopic measurement methods counting particle numbers are hardly suitable as detection methods, because there are plenty of natural particles next to a small number of MP particles. Integral methods, such as thermoanalytical methods are determining the particle mass independently of the inorganic components.In this study, a workflow for sample preparation via density separation and subsequent analysis by thermal extraction desorption‐gas chromatography/mass spectrometry is presented, which leads to representative and homogeneous samples and allows fast and robust MP mass content measurements suitable for routine analysis. Polymers were identified and quantified in all samples. Polyethylene and styrene‐butadiene rubber are the dominant polymers, besides polypropylene and polystyrene. Overall, total polymer masses between 1.18 and 337.0 µg/g could be determined. Highest MP concentrations in riverbed sediment are found in sites characterized by low flow velocities in harbors and reservoirs, while MP concentrations in sandy/gravelly bed sediments with higher flow velocities are small.
KW - Microplastics
KW - Density separation
KW - TED-GC/MS
KW - NaI
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597335
DO - https://doi.org/10.1002/appl.202200125
VL - 3
IS - 2
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-59733
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wolf, S. E.
A1 - Müller, L.
A1 - Barrea, R.
A1 - Kampf, C.J.
A1 - Leiterer, Jork
A1 - Panne, Ulrich
A1 - Hoffmann, T.
A1 - Emmerling, Franziska
A1 - Tremel, W.
T1 - Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates
N2 - During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed.
PY - 2011
DO - https://doi.org/10.1039/c0nr00761g
SN - 2040-3364
SN - 2040-3372
IS - 3
SP - 1158
EP - 1165
PB - RSC Publ.
CY - Cambridge
AN - OPUS4-23355
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - INPR
A1 - Battistella, Beatrice
A1 - Revill, Adam
A1 - Venzago, Cornel
A1 - Hoffmann, Volker
A1 - Agudo Jácome, Leonardo
A1 - Al-Sabbagh, Dominik
A1 - Recknagel, Sebastian
A1 - Abad Andrade, Carlos Enrique
T1 - Depth-Resolved Lithium Isotope Fractionation as a Diagnostic of Interphase Evolution and Degradation in Lithium Ion Batteries
N2 - Lithium isotopic fractionation is well-established in dynamic geochemical systems; however, its role in lithium-ion batteries (LIBs) remains uninvestigated. Herein, we report the first depth-resolved demonstration that isotopic separation occurs during Li-ion cell operation whose magnitude depends on the cycling history. Using depth-resolved glow discharge mass spectrometry, we monitored the 7Li/6Li ratio in LiNi0.333Mn0.333Co0.333O2 (NMC111)||graphite coin cell electrodes at defined life-cycle stages. Different charging rates were examined to get mechanistic insight into kinetic and thermodynamic control in the fractionation process. Although pristine electrodes exhibit a uniform isotopic ratio, cycled electrodes show a distinct 7Li enrichment in the positive electrode and a corresponding accumulation of 6Li at the surface of the negative electrode. The degree of isotopic separation varies with the charging rate. Isotopic signatures correlate with capacity fading, indicating lithium isotope mapping as a sensitive diagnostic tool for tracking electrode degradation and the evolution of the electrode–electrolyte interphases in LIBs.
KW - Li-ion batteries
KW - Lithium isotopes
KW - Post-mortem analysis
KW - GD-MS
KW - Depth profile
KW - Mass spectrometry
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651287
DO - https://doi.org/10.26434/chemrxiv-2025-5rvlk
SP - 1
EP - 19
AN - OPUS4-65128
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Battistella, Beatrice
A1 - Revill, Adam
A1 - Venzago, Cornel
A1 - Hoffmann, Volker
A1 - Agudo Jácome, Leonardo
A1 - Al-Sabbagh, Dominik
A1 - Recknagel, Sebastian
A1 - Abad, Carlos
T1 - Depth-Resolved Lithium Isotope Fractionation as a Diagnostic of Interphase Evolution and Degradation in Lithium-Ion Batteries
N2 - Lithium isotopic fractionation is well-established in dynamic geochemical systems; however, its role in lithium-ion batteries (LIBs) remains uninvestigated. Herein, we report the first depth-resolved demonstration that isotopic separation occurs during Li-ion cell operation whose magnitude depends on the cycling history. Using depth-resolved glow discharge mass spectrometry, we monitored the 7Li/6Li ratio in LiNi0.333Mn0.333Co0.333O2 (NMC111)||graphite coin cell electrodes at defined life-cycle stages. Different charging rates were examined to get mechanistic insight into kinetic and thermodynamic control in the fractionation process. Although pristine electrodes exhibit a uniform isotopic ratio, cycled electrodes show a distinct 7Li enrichment in the positive electrode and a corresponding accumulation of 6Li at the surface of the negative electrode. The degree of isotopic separation varies with the charging rate. Isotopic signatures correlate with capacity fading, indicating lithium isotope mapping as a sensitive diagnostic tool for tracking electrode degradation and the evolution of the electrode–electrolyte interphases in LIBs.
KW - Lithium-Ion Battery
KW - Li Isotopes
KW - Glow Discharge Mass Spectrometry GD-MS
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657229
DO - https://doi.org/10.1021/acsenergylett.5c0413737
SN - 2380-8195
VL - 11
IS - 3
SP - 2851
EP - 2857
PB - ACS Publications
AN - OPUS4-65722
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Appelhans, Dietmar
A1 - Oertel, U.
A1 - Mazzeo, R.
A1 - Komber, H.
A1 - Hoffmann, J.
A1 - Weidner, Steffen
A1 - Brutschy, B.
A1 - Voit, B.
A1 - Ottaviani, M.F.
T1 - Dense-shell glycodendrimers: UV/Vis and electron paramagnetic resonance study of metal ion complexation
N2 - The development of dendritic metal ion carrier systems for use in a biological environment is a challenging task as the carrier system must possess multiple features (e.g. a protective shell for metal decomplexation, targeting functions, metal-intradendrimer complexes, etc.) to substitute for the function of metal proteins in processes such as copper metabolism. Thus, Cu(II) complexation by a series of poly(propyleneimine) glycodendrimers ranging up to the fifth generation that have either a dense maltose or maltotriose shell was investigated by UV/Vis spectroscopy and electron paramagnetic resonance (EPR). As a necessary step towards potential biological application, we elucidated the complexation capacity, location of the Cu(II)-dendrimer complexes and the Cu(II) coordination sphere in the dendritic environment. A generation-dependent Cu(II) complexation was found. Furthermore, analysis of the EPR spectra revealed that internal and external Cu(II) coordination and the symmetry (axial and rhombic) of the generated complexes depend on the oligosaccharide shell, dendrimer generation and the relative concentrations of Cu(II) and the dendrimers. Both axial and rhombic symmetries are generation dependent, but also distort with increasing generation number. External coordination of Cu(II) is supported by sugar groups and water molecules. Finally, a third-generation dendrimer with a maltose shell was used to explore the general complexation behaviour of the dendritic poly(propyleneimine) scaffold towards different metal ions [Cu(II), Ag(I), VO(IV), Ni(II), Eu(III) and UO2(VI)].
KW - Glycodendrimers
KW - Metal ion complexation
KW - Metal ion-intradendrimer complexes
KW - Electron paramagnetic resonance study
PY - 2010
DO - https://doi.org/10.1098/rspa.2009.0107
SN - 1364-5021
SN - 0962-8444
SN - 0080-4630
SN - 0950-1207
SN - 1471-2946
VL - 466
SP - 1489
EP - 1513
CY - London, UK
AN - OPUS4-21622
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Laux, Eva-Maria
A1 - Behnke, Thomas
A1 - Hoffmann, Katrin
A1 - Resch-Genger, Ute
T1 - Keeping particles brilliant - simple methods for the determination of the dye content of fluorophore-loaded polymeric particles
N2 - One of the most active research areas in the life and material sciences is the design and synthesis of fluorescent nano- and micrometre sized particles for applications e.g. as labels, sensor systems, and platforms for fluorescence assays or barcoding materials. The reliable and reproducible fabrication of such particles as well as many applications require accurate, simple, and versatile procedures for the determination of the dye content per particle which affects e.g. the brightness of these materials and their surface charge and thus, colloidal stability. Here, four fast and inexpensive spectroscopic methods for the quantification of the fluorophore content of beads are presented and compared for nanometre- and micrometre sized polystyrene particles loaded or labeled with commercial fluorophores, differing in dye class, charge, and hydrophilicity. This included the determination of the amount of incorporated dye from absorption spectra of bead suspensions, via dissolving of the polymer matrix, via extraction of the polymer matrix, and from the supernatant of the swelling solution or reaction mixture. Method validation was performed with a sulfur-containing dye and elemental analysis. Based upon this method comparison and the accomplishable uncertainties, two reliable strategies for particle characterization and bead process control are identified that can be easily extended to other materials.
PY - 2012
DO - https://doi.org/10.1039/c2ay05822g
SN - 1759-9660
SN - 1759-9679
VL - 4
IS - 6
SP - 1759
EP - 1768
PB - RSC Publ.
CY - Cambridge
AN - OPUS4-26051
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Grunert, B.
A1 - Saatz, Jessica
A1 - Hoffmann, Katrin
A1 - Appler, F.
A1 - Lubjuhn, Dominik
A1 - Jakubowski, Norbert
A1 - Resch-Genger, Ute
A1 - Emmerling, Franziska
A1 - Briel, A.
T1 - Multifunctional rare-earth element nanocrystals for cell labeling and multimodal imaging
N2 - In this work, we describe a simple solvothermal route for the synthesis of Eu3+-doped gadolinium orthovanadate nanocrystals (Eu:GdVO4−PAA) functionalized with poly(acrylic)acid (PAA), that are applicable as cell labeling probes for multimodal cellular imaging. The Eu3+ doping of the vanadate matrix provides optical functionality, due to red photoluminescence after illumination with UV light. The Gd3+ ions of the nanocrystals reduce the T1 relaxation time of surrounding water protons, allowing these nanocrystals to act as a positive MRI contrast agent with a r1 relaxivity of 1.97 mM−1 s−1. Low background levels of Eu3+, Gd3+, and V5+ in biological systems make them an excellent label for elemental microscopy by Laser Ablation (LA)-ICP-MS. Synthesis resulted in polycrystalline nanocrystals with a hydrodynamic diameter of 55 nm and a crystal size of 36.7 nm, which were further characterized by X-ray diffraction (XRD), photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The multifunctional nanocrystals were subsequently used for intracellular labeling of both human adipose-derived stem cells (MSCs) and A549 (adenocarcinomic human alveolar basal epithelial) cells.
KW - Bioimaging
KW - Nanoparticle
KW - Multimodal
KW - Lanthanide
PY - 2018
DO - https://doi.org/10.1021/acsbiomaterials.8b00495
SN - 2373-9878
VL - 4
IS - 10
SP - 3578
EP - 3587
PB - ACS Publications
CY - Washington, USA
AN - OPUS4-46244
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scholz, Philipp
A1 - Wachtendorf, Volker
A1 - Elert, Anna Maria
A1 - Falkenhagen, Jana
A1 - Becker, Roland
A1 - Hoffmann, Katrin
A1 - Resch-Genger, Ute
A1 - Tschiche, Harald
A1 - Reinsch, Stefan
A1 - Weidner, Steffen
ED - Scholz, Philipp
T1 - Analytical toolset to characterize polyurethanes after exposure to artificial weathering under systematically varied moisture conditions
N2 - Polyether and -ester urethanes (PU) were exposed to artificial weathering at 40 °C and artificial UV radiation in a weathering chamber. In 3 parallel exposures, humidity was varied between dry, humid, and wet conditions. Material alteration was investigated by various analytical techniques like size exclusion chromatography
(SEC), liquid chromatography-infrared spectroscopy (LC-FTIR), thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS), fluorescence mapping and dynamic mechanical analysis (DMA). Our results show that depending on the weathering conditions, different degradation effects can be observed. By means of SEC an initial strong decrease of the molar masses and a broadening of the mass distributions was found. After a material dependent time span this was followed by a plateau where molar mass changes were less significant. A minor moisture-dependent degradation effect was only found for polyester PU. Fluorescence measurements on two materials revealed an increase in the luminescence intensity upon weathering process reaching a saturation level after about 500 h. The changes in the optical properties observed after different exposure conditions and times were very similar. The TD-GC-MS data showed the fate of the stabilizers and antioxidant in the course of weathering. LC-FTIR measurements revealed a change in peak intensities and the ratio of urethane and carbonyl bands.
KW - Polyurethane
KW - Artificial weathering
KW - Moisture
KW - Crosslinking
KW - Degradation
PY - 2019
UR - https://www.sciencedirect.com/science/article/pii/S0142941819303708
DO - https://doi.org/10.1016/j.polymertesting.2019.105996
SN - 0142-9418
VL - 78
SP - 105996, 1
EP - 9
PB - Elsevier
CY - Amsterdam
AN - OPUS4-48625
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hoffmann, Martin
A1 - Gregor, Christian
A1 - Schulz, Michael
A1 - Szczepaniak, Mariusz
A1 - Mair, Georg W.
T1 - Entwickelt und validiert - Probengeometrie zur Untersuchung von gewickelten Faserverbundproben
N2 - Durch die beschriebene, auf eine Umfangsbelastung ausgelegte Probengeometrie werden Fertigung und Einsatz von Druckbehältern nachempfunden. Dafür wurden bereits bestehende Probenformen überarbeitet, um im Probenkörper eine unidirektionale Zugbelastung zu erzeugen. Da die endgültigen Eigenschaften von faserverstärktem Kunststoff erst in der Fertigung entstehen, sind gleiche Fertigungsbedingungen von Proben und Bauteilen wichtig. Die hier vorgestellte Probe verspricht dadurch eine gute Eignung für den Einsatz bei Untersuchungen zum Zeitstandsverhalten.
KW - Faserverstärkte Kunststoffe (FVK)
KW - Druckbehälter
KW - Zeitstand
KW - Zugprobe
PY - 2012
SN - 1865-4819
VL - 5
SP - 44
EP - 49
PB - Springer Vieweg, Springer Fachmedien Wiesbaden GmbH
CY - Wiesbaden
AN - OPUS4-26893
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -