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This report contains detailed information on the preparation of the reference material as well as on homogeneity and stability investigations of the property of interest, the equivalent particle diameter, and on the analytical methods to determine the additional properties. The values for particle size distribution are based on the results from laser diffraction measurements of 3 different devices with at least 3 replicate measurements of 4 randomly chosen units of the reference material P206.
Preliminary results of an interlaboratory comparison on microplastics organised by plasticsfate
(2023)
Microplastics are everywhere in the environment, but analytics is challenging. Since harmonisation is missing as well es suitable reference materials, BAM did under th umbrella of VAMAS funded by the EU Horizon 2020 project PlasticsFate a ILC for microplastic detection methods. Methods adressed were IR, Raman, Py-GC/MS and TED-GC/MS. The talk gives a first presentation and evaluation on the results.
Owing to a growing shortage of fluorspar, a raw material used for producing fluorinated base chemicals, fluorspar has been named among the 30 critical raw materials in the EU. 1 However, the sustainable transfer of fluorine atoms from one molecule to another using heterogeneous catalysts has not yet been reported. Herein, we present the heterogeneous catalyst zirconium chloro fluoride (ZCF) that performs dehydrofluorination of a fluoroalkane and consecutive hydrofluorination of an alkyne at room temperature.
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.
The presentation demonstrates an application of multi-scale optical imaging methods such as spectroscopic imaging ellipsometry and white light interference microscopy for the investigation of wide-bandgap semiconductors for power electronics. The capabilities of these methods for the development of new reference calibration samples for scanning microwave microscopes (SMM) and conductive atomic force microscopes (C AFM) are discussed.
The use of a dedicated approach: DoE for synthesis + characterization + Chemometric Analysis, is a valuable method for the safe-by-design synthesis of several types of materials for large-scale application in catalysis, energy harvesting, biomedical and environmental applications, etc. This approach is not only related to the material synthesis, but can be expanded to any type of molecules/material, with relevant saving of solvents, energy and times.
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.
Amorphous materials play an important role in C-F bond activation but face the difficulty of limited available structural information by methods such as powder XRD and solid-state MAS NMR spectroscopy especially if the nucleus is not abundant enough. Here, we present heterogeneous catalysts, active in C-F bond activation, where EXAFS allowed specifically elucidating the local structure, which would have not been possible elsewise.
The main objective was to assess homogeneity of two bimodal gold materials, namely nPsize1 and nPSize2, containing approximately 1:1 and 10:1 particle number-based ratio of ~30nm and ~60nm particles. Particle number-based concentration within the two size fractions was determined with spICP-MS using the particle frequency method of calibration.