Analytische Chemie
Filtern
Erscheinungsjahr
- 2022 (89) (entfernen)
Dokumenttyp
- Posterpräsentation (89) (entfernen)
Referierte Publikation
- nein (89)
Schlagworte
- Fluorescence (6)
- BAMline (5)
- Process Analytical Technology (4)
- X-ray imaging (4)
- Additive manufacturing (3)
- Amperometry (3)
- Benchtop NMR (3)
- Bioinformatics (3)
- Luminescence (3)
- Metrology (3)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (38)
- 8 Zerstörungsfreie Prüfung (27)
- 6 Materialchemie (18)
- 1.8 Umweltanalytik (10)
- 8.5 Röntgenbildgebung (10)
- 6.1 Oberflächen- und Dünnschichtanalyse (9)
- 1.1 Anorganische Spurenanalytik (6)
- 1.2 Biophotonik (6)
- 4 Material und Umwelt (6)
- 6.3 Strukturanalytik (6)
- 1.4 Prozessanalytik (5)
- 1.9 Chemische und optische Sensorik (5)
- 8.0 Abteilungsleitung und andere (5)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (5)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (5)
- VP Vizepräsident (5)
- VP.1 eScience (5)
- 6.6 Physik und chemische Analytik der Polymere (4)
- 8.4 Akustische und elektromagnetische Verfahren (4)
- 1.6 Anorganische Referenzmaterialien (3)
- 1.7 Organische Spuren- und Lebensmittelanalytik (3)
- 4.2 Material-Mikrobiom Wechselwirkungen (3)
- 1.5 Proteinanalytik (2)
- 1.3 Instrumentelle Analytik (1)
- 3 Gefahrgutumschließungen; Energiespeicher (1)
- 3.5 Sicherheit von Gasspeichern (1)
- 4.1 Biologische Materialschädigung und Referenzorganismen (1)
- 4.3 Schadstofftransfer und Umwelttechnologien (1)
- 4.5 Kunst- und Kulturgutanalyse (1)
- 8.6 Faseroptische Sensorik (1)
The evaluation of technical components and materials in terms of condition and quality with the aid of non-destructive testing methods plays an outstanding role both in industrial serial production and in the individual assessment of components. The ultrasonic echo method is used for a wide variety of testing tasks, such as measuring the thickness of a component. At the Bundesanstalt für Materialforschung und -prüfung (BAM) in Berlin, test methods are developed and their performance is demonstrated. For this purpose, references such as materials, test procedures or data sets are generated, which are used to evaluate these developed test methods. An important component of these references are data sets that are created according to the BAM Data Policy and made available to the scientific community and users of test methods in practice on the basis of the FAIR principles (Findability, Accessibility, Interoperability, and Reuse).
Bisphenol A (BPA) is used in Polycarbonate, Polyacrylic resins, Polysulfones, Epoxy resins, and Polyetherimides. It is also used in recycled Polyvinyl chloride [1–3]. BPA has been classified as a substance of very high concern (SVHC) under REACH [4] due to its endocrine disrupting properties. The German competent authorities want to reduce the content of BPA in the environment. Possible substitutes for BPA are Bisphenol B (BPB), Bisphenol E (BPE),
Bisphenol F (BPF), or Bisphenol S (BPS), as they are similar in structure.
BPA-based materials have a wide area of application especially outside. These outdoor applications are exposed to different external influences, including physical, biological, mechanical and chemical influences. This results in damage and aging of the material with leaching or migration into the environment. There, the substance is transformed by various transformation processes. The emerging metabolites and transformation products (TPs) can have different properties than the parent substance. Understanding the fate and behavior of the emerging pollutants is very important.
Therefore, different transformation products of selected bisphenols will be generated and analyzed:
To investigate the fate of different bisphenols in water treatment plants technical transformation products [5] will be generated by chlorination, ozonization, the Fenton reaction, and UV-radiation.
For the investigation of the fate of Bisphenols in surface water global radiation will be simulated with UVA-lamps
Simulation of phase-I-metabolism with an electrochemical cell coupled to mass spectrometry (EC-MS).
Natural and synthetic estrogens are key endocrine-disrupting chemicals. Despite occurring at ultra-trace levels (below ng L-1), it is believed that they are contributing to an increase in feminized fish and other endocrine disruptive effects, and hence, their inclusion in the Watch list was not unexpected. One of the main sources ofestrogens to surface waters is wastewater effluent. Once in surface waters, they can partition into different compartments, i.e., water and suspended particulate matter. For this reason, there is an urgent need for a methodology to monitor estrogen levels below the environmental quality standards (EQS) set by the Water Framework Directive requirements.
In this study, a precise and accurate gas chromatography-mass spectrometry method (GC-MS/MS) for the analysis of estrone (E1), 17β-estradiol (17β-E2), 17α-estradiol (17α- E2), 17-alpha-ethinylestradiol (EE2), and estriol (E3) in whole water samples with ng L-1 limit of quantification (LOQ) was developed and validated in accordance with CEN/TS 16800:2020 guidelines.
Monitoring programs should generate high-quality data on the concentrations of substances and other pollutants in the aquatic environment to enable reliable risk assessment. Furthermore, the need for comparability over space and time is critical for analysis of trends and evaluation of restoration of natural environment. Additionally, research work and exercises at the European level have highlighted that reliable measurements of estrogenic substances at the PNEC level are still challenging to achieve.
The project EDC-WFD Metrology for monitoring endocrine disrupting compounds under the EU Water Framework Directive aims to develop traceable analytical methods for determining endocrine disrupting compounds and their effects, with a specific focus on three estrogens of the first watch list (17-beta-estradiol (17βE2), 17-alpha-ethinylestradiol (EE2), and estrone (E1)). Estrogens 17-alpha-estradiol (17E2) and estriol (E3) will be included to demonstrate the reliability of the developed methods and to support the requirements of Directive 2013/39/EC, Directive 2009/90/EC and Commission Implementation Decision (EU) 2018/840, hence improving the comparability and compatibility of measurement results within Europe. During the EDC-WFD project four selected effect-based methods (EBM) will be deeply investigated in order to improve their rationale use and their support in water quality assessment. In particular, the EBM sensitivity, specificity and accuracy on reference materials with single or mixture solutions of the five substances at a concentration of EQS values will be explored.
This contribution will present the objectives and methods applied within the EDC-WFD project.
The Federal Institute for Materials Research and Testing (BAM) organised an interlaboratory comparison (ILC) for the characterisation of 87Sr/86Sr isotope ratios in limestone (IAG/CGL ML-3) and Penrhyn slate (IAG OU-6) reference materials by applying the conventional method for 87Sr/86Sr isotope ratios. Samples were sent to thirteen analytical laboratories . Since both samples are powdered, rock materials, dissolution of the sample and Sr isolation via ion exchange chromatography were mandatory. This was done using acid, microwave/acid, bomb/acid digestion or borate fusion and subsequent isolation of Sr by means of commercially available ion exchange resins. In this study, we present and discuss the potential effects that differences between laboratories, and between two instrumental measurement techniques (i.e., MC-ICP-MS and MC-TIMS), may have upon the dispersion of measurement results of the 87Sr/86Sr isotope ratio in the two aforementioned reference materials. We used a statistical mixed effects model to assess the potential effects of both the laboratory and the measurement technique. Consensus values for both materials and associated standard uncertainties {(IAG/CGL ML-3 (0.708245±0.000004) mol/mol; IAG OU-6 (0.729769±0.000008) mol/mol} were estimated by fitting a linear, Gaussian mixed effects model (Pinheiro and Bates 2000) using the R function “lmer” defined in package “lme4”. The statistical results showed that there is no significant effect attributable to differences between instrumental techniques when both materials are considered together, or separately. The p-value of the test of significance of the measurement technique effect is greater than 0.54. For both materials there were statistically significant effects attributable to differences between laboratories when the measurement results for both materials were considered together and separately. This effect is less than 0.00004 in absolute value. However, for neither material did consideration or disregard for such differences induce significant changes in the estimate of the consensus value for the 87Sr/86Sr isotope ratio. Therefore, the effects attributable to differences between instrumental techniques or between laboratories can safely be disregarded when computing the best estimate for the true value of 87Sr/86Sr isotope ratio in these materials, by the community of expert laboratories represented in this study.
Nanoparticles (NPs) have become important materials for a variety of chemical technologies, including catalysis. One of the main challenges is the reduction of green house gases, such as CO2. One opportunity besides the capturing is the conversion to synthesis gas via the reverse water-gas shift reaction.
A facile and efficient method is described for the solvothermal synthesis of size-tunable, stable, and uniform NiCu core-shell NPs. The diameter of the NPs can be tuned in a range from 6 nm to 30 nm and the Ni:Cu ratio from 30:1 to 1:1. The NPs are structurally characterized with combination of transmission electron microscopy, anomalous small-angle X-ray scattering, X-ray photoelectron spectroscopy, and X-ray absorption fine structure. Using these analytical methods, a core-shell-shell structure their chemical composition is elucidated. A depletion from the core to the shell is observed, with the core consisting of NiCu alloy, surrounded by an inner Ni-rich shell and an outer NiO shell. The SiO2-supported NiCu core-shell NPs show pronounced selectivity of >99% for CO in the catalytic reduction of CO2 to CO using hydrogen as reactant (reverse water–gas shift reaction).
In mass spectrometry based proteomics, protein homology leads to
many shared peptides within and between species. This complicates
taxonomic inference. inference. We introduce PepGM, a graphical model for taxonomic profiling of viral proteomes and metaproteomic datasets.
Using the graphical model, our approach computes statistically sound
scores for taxa based on peptide scores from a previous database
search, eliminating the need for commonly used heuristics.
In mass spectrometry based proteomics, protein homology leads to
many shared peptides within and between species. This complicates
taxonomic inference. inference. We introduce PepGM, a graphical model for taxonomic profiling of viral proteomes and metaproteomic datasets.
Using the graphical model, our approach computes statistically sound
scores for taxa based on peptide scores from a previous database
search, eliminating the need for commonly used heuristics. heuristics.
Probability based taxonomic profiling of viral and microbiome samples using PepGM and Unipept
(2022)
In mass spectrometry based proteomics, protein homology leads to many shared peptides within and between species. This complicates
taxonomic inference in samples of unknown taxonomic origin. PepGM uses a graphical model for taxonomic profiling of viral proteomes and
metaproteomic datasets providing taxonomic confidence scores. To build the graphical model, a list of potentially present taxa needs to be
inferred. To this end, we integrate Unipept, which enables the fast querying of potentially present taxa. Together, they allow for taxonomic
inference with statistically sound confidence scores.
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%.
We interpret solving the multi-vehicle routing problem as a team Markov game with partially observable costs. For a given set of customers to serve, the playing agents (vehicles) have the common goal to determine the team-optimal agent routes with minimal total cost. Each agent thereby observes only its own cost. Our multi-agent reinforcement learning approach, the so-called multi-agent Neural Rewriter, builds on the single-agent Neural Rewriter to solve the problem by iteratively rewriting solutions. Parallel agent action execution and partial observability require new rewriting rules for the game. We propose the introduction of a so-called pool in the system which serves as a collection point for unvisited nodes. It enables agents to act simultaneously and exchange nodes in a conflict-free manner. We realize limited disclosure of agent-specific costs by only sharing them during learning. During inference, each agents acts decentrally, solely based on its own cost. First empirical results on small problem sizes demonstrate that we reach a performance close to the employed OR-Tools benchmark which operates in the perfect cost information setting.
Hybrid optical measurement technique for detection of defects in epitaxially grown 4H-SiC layers
(2022)
Recent developments in power electronics require the use of new wide bandgap compound semiconductors. Silicon carbide (SiC) is one of the most promising materials for power electronics due to its outstanding properties and commercial availability. Some types of defects in the SiC substrates or homoepitaxial SiC layers can affect the performance of electronic devices in a serious manner or make its operation even impossible. Optical methods such as imaging ellipsometry (IE) and white light interference microscopy (WLIM) were applied for fast and non-contact investigation of defects in the epitaxially grown 12 µm 4H-SiC layers on 4H- SiC substrates.
Ellipsometry enables the investigation of material properties over a broad spectral range. As a fast and non-destructive method, it is widely used in industry for quality assurance. Despite the wide application of ellipsometry and its high industrial relevance there are some material-specific standards and there have been no generally accepted standards dealing with model validation and measurement uncertainties. The first German standard DIN50989-1: 2018 Ellipsometry – Part1: Principles (currently international standard ISO 23131: 2021) marks the beginning of a 6-part standard series for ellipsometry, which was developed under consideration of GUM.
Introduction:
With the introduction of accurate deep learning predictors, spectral matching applications might experience a renaissance in tandem mass spectrometry (MS/MS) driven proteomics. Deep learning models, e.g., Prosit, predict complete MS/MS spectra from peptide sequences and give the unprecedented ability to accurately predict mass spectra that may arise from any given proteome. However, the amount of spectral data is enormous when querying large search spaces, e.g., metaproteomes composed of many different species.
Current spectral library search software, such as SpectraST, is not equipped to meet run time and memory constraints imposed by such large MS/MS databases, covering several millions of peptide spectrum predictions.
Methods:
Inspired by the fragment index data structure that had been introduced with MSFragger, we implement an efficient peak matching algorithm for computing spectral similarity between query and library spectra. Mistle (Metaproteomic index and spectral library search engine) uses index partitioning and SIMD (Single instruction, multiple data) intrinsics, which greatly improves speed and memory efficiency for searching large spectral libraries. Mistle is written in C++20 and highly parallelized.
Results:
We demonstrate the efficiency of Mistle on two predicted spectral libraries for the lab-assembled microbial communities 9MM and SIHUMIx. Compared to the spectral library search engine SpectraST, Mistle shows a >10-fold runtime improvement and is also faster than msSLASH, which uses locality-sensitive hashing. Although Mistle is slower than MSFragger, Mistle‘s memory footprint is an order of magnitude smaller. Furthermore, we find evidence that the spectral matching approach to predicted libraries identifies peptides with higher precision. Mistle detects peptides not found by database search via MSFragger and in turn uncovers unnoticed false discoveries among their matches.
Conclusion:
In this study, we show that predicted spectral libraries can enhance peptide identification for metaproteomics. Mistle provides the means to efficiently search large-scale spectral libraries, highlighted for the microbiota 9MM and SIHUMIx.
In order to detect small and hidden material defects or micro-cracks, weak and localized magnetic stray fields need to be detected and characterized on the magnetic surface. Current flux leakage sensor elements are rigid and rely on air gaps to detect stray fields several hundred micrometers above the surface. Furthermore, the increasing complexity of critical components, enabled by novel fabrication technologies, primarily additive manufacturing, poses a significant challenge to the available flux leakage testing technologies.
The emergence of flexible magneto-electronics paves the way to a compliant form of magnetic sensors that, on one hand, are able to adapt to highly curved surfaces, allowing these measurements to be conducted on irregularly formed components, which are inaccessible for nowadays electromagnetic NDT equipment and, on the other hand, could enhance the detection limit for small magnetic stray fields, by allowing the magneto-sensitive elements to approximate the object’s surface until only a few µm, mediated by thin and flexible packaging.
Mycotoxins (toxic compounds formed by fungi) in food and feed have caused problems for mankind since the beginning of time. The group of ergot alkaloids plays a special role in human history. Several tens of thousands of deaths during the middle ages caused by to ergotism (the disease caused by continuous intake of ergot alkaloid contaminated food) underscore the importance of reliable analytical methods to ensure food safety.
More than 50 compounds belong to the group of ergot alkaloids. The 12 most found structures – the major ergot alkaloids – are typically measured, when it comes to ergot alkaloid quantification. High performance liquid chromatography (HPLC) with a fluorescence detector (FLD) is typically used to quantify the ergot alkaloid content. The main disadvantage of this method are the high costs for calibration standards (12 different calibration substances are required). But also, the time and effort required for the analysis of 12 peaks and overlapping signals that occur in complex food samples such as bread. As all ergot alkaloids share the ergoline structure and just differ in the substituents attached to this backbone, measurement of all ergot alkaloids in one sum parameter presents a time and cost saving alternative. The most important step for the development of such a sum parameter method is the reaction used to transfer all ergot alkaloids to one uniform structure. Two promising reactions, the acidic esterification to lysergic acid methyl ester and hydrazinolysis to lysergic acid hydrazide, were examined for possible use in a routine analysis method. In addition to yield and reaction rate, factors such as handling of the reaction and the possibility of parallel sample workup play a role.
A recent upgrade of key equipment of the BAMline widens its imaging capabilities: shorter scan acquisition times are now possible, in situ and operando studies can now be routinely performed, and different energy spectra can easily be set up. In fact, the upgraded double-multilayer monochromator brings full flexibility by yielding different energy spectra to optimize flux and energy resolution as desired.
Deciphering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS
(2022)
Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. The information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials research.
References.
Direct detection of glyphosate in water with fluorescent molecularly imprinted polymer particles
(2022)
Analysis of environmental contaminants such as pesticides is increasing in importance due to frequent detection of residues in water reserves and food stuff, as well as lowering of maximum residue levels (MRLs). Molecularly imprinted polymers (MIPs) have been developed for preconcentration of these analytes prior to analysis by chromatographic techniques [1]. MIPs are prepared by polymerization of monomers in a matrix containing the analyte, followed by extraction of the analyte to obtain binding sites that are complementary to the analyte of interest. Recently, our group developed MIPs containing fluorescent reporter molecules that can be used for direct detection and quantification of 2,4-D in contaminated water. Core/shell MIP particles were employed, consisting of sub-micron silica nanoparticles coated with a MIP shell containing a fluorescent reporter whose signal was enhanced upon binding with 2,4-D in water. A limit of detection of 20 nM was attained [2]. We present here a comparable system, composed of fluorescent core-shell MIPs for the direct analysis of pesticides in environmental samples.
Perfluorocarboxylic acids (PFCAs) are a family of compounds that consist of a fully perfluorinated carbon backbone and a carboxylic acid moiety1. PFCAs have been classified as substances of very high concern by REACH regulations due to their persistence in the environment, non biodegradability and toxicological effects2. Thus, there is significant interest in detecting PFCAs in ground, waste, surface and drinking water. Fluorescence detection is a portable, easy-to-operate and cost-effective alternative, enabling the onsite detection of these analytes e.g., with miniaturized fluidic sensors.
Here, a guanidine benzoxadiazole (BD) dye covalently attached to a polymerizable methacrylate unit was developed for the integration of the dye into polymers and on surfaces. The response behavior of the dye toward PFCAs was assessed in monophasic (EtOAc) and biphasic (EtOAc-H2O) solvent systems, the biphasic system being advantageous for the extraction of the hydrophobic organic acids from the aqueous phase.
The BD dye was integrated into sensory silica core-polymer shell particles for the sensing of PFCAs directly in aqueous media. Submicron SiO2 particles were functionalized with 3 (trimethoxysilyl)propyl methacrylate followed by radical polymerization with the BD dye and ethylene glycol dimethacrylate. TEM images showed a homogeneous polymer shell with a thickness of 75±2 nm.
By incorporating the BD dye into core-shell particles, lower limits of detection (1.52 µM for perfluorooctanoic acid, PFOA) were achieved if compared to the use of the neat BD dye in a biphasic assay (17.3 µM for PFOA), and excellent discrimination against inorganic acids thanks to the hydrophobic polymer shell. The particle sensory platform has proven to be an alternative for the sensing of PFCAs directly in water.
Mechanochemistry offers a unique opportunity to modify or synthesize new crystal forms. Although the method is very promising, little is known about the mechanochemical means to control the synthesis of a solid form. Using an polymorphic organic cocrystal system, we show here that mechanochemistry can be used to obtain a polymorph transformation under the apparently conventional (thermal) transition point.
In many cases, science falls back on self-developed prototype systems, which are used and developed for the measurement and execution of the tasks. About 80 % of the development is based on the same hardware design, which is used in only one application scenario and then discarded. For the most part, there are also uncalibrated sensors, since it is costly to calibrate a complicated sensor measurement system or the entire measurement chain since access to the sensor systems is not always available. This paper describes a conceptual design to implement a versatile sensor system with the motivation to fuse the data recording and data reception, which can cover large areas with the help of LoRaWAN (Long Range Wide Area Network) technology [1, 2]. To overcome disadvantages of LoRaWAN, namely the slow data rates, the proposed sensor system can also cover smaller areas with the widespread WiFi technology. An enormous advantage over individual complete systems in the form of a prototype, is the rapid expansion, uncomplicated calibration of the individual sensors and the ecological relief.
A modular design is used, where individual stacks with sensors and peripherals can be added separately. The stacks are standalone low-power systems and can be calibrated, maintained, and replaced separately and do not require the entire measurement chain. The measured and sent values are stored locally on the main stack and sent to the data collector (gateway) and evaluated by means of the automated selection between WiFi and LoRaWAN.
New Reference Materials for Quantification and Standardization of Fluorescence-based Measurements
(2022)
Luminescence techniques are amongst the most commonly used analytical methods in the life and material sciences due to their high sensitivity and non-destructive and multiparametric character. Photoluminescence signals are, however, affected by wavelength-, polarization-, and time-dependent instrument specific effects and the compound-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements, while the relative determination of the latter requires suitable quantum yield standards with well-known photoluminescence quantum yields. For the simple correction of instrument specific effects in the wavelength region of 300 nm to 950 nm, the set of the five certified spectral fluorescence standards (CRM) BAM-F001 – BAM-F005, has been extended to the NIR range by including two new fluorescence standards currently under certification.
Als bildgebendes und zerstörungsfreies Verfahren eignet sich die Röntgen-Computertomographie (CT) insbesondere bei der Untersuchung von Kunst- und Kulturgütern. Die für Werkstoffprüfung und Materialanalyse konzipierten CT-Anlagen bieten dank hoher Röntgenleistung die Möglichkeit zusätzlich zu Holz, Keramiken und Kunststoffen auch stark schwächende Materialien, wie bspw. Metalle, zu durchdringen. Für eine hohe räumliche Auflösung im unteren Mikrometerbereich (2-200µm) sorgen entsprechend ausgelegte CT-Anlagen. In der Bundesanstalt für Materialforschung und -prüfung (BAM) stehen mehrere solcher CT-Anlagen für unterschiedliche Fragestellungen sowie Probengrößen und - materialien zur Verfügung. Einige Beispiele aus den vergangenen Arbeiten der BAM veranschaulichen das große Potential dieser Untersuchungsmethode.
Da bei einer CT-Messung in der Regel das gesamte Untersuchungsobjekt erfasst und in ein digitales Volumenmodell überführt wird, eröffnet sich für Archäologen und Restoratoren die Möglichkeit Untersuchungen hinsichtlich Materialzusammensetzung, Erhaltungszustand und Herstellungstechnik am virtuellen Objekt vorzunehmen, ohne die Originalsubstanz zu beeinträchtigen. Gegenüber der klassischen Radiografie, bei der nur eine zweidimensionale Abbildung erreicht wird, bietet die CT-Untersuchung die Möglichkeit innenliegende Strukturen dreidimensional zu erfassen. Die notwendige Bestimmung der Objektoberfläche erlaubt zudem die Erstellung eines Oberflächenmodells des untersuchten Gegenstandes. Damit lassen sich unter anderem mechanische Simulationen (Belastung, Durchbiegung, Durchströmung) durchführen. Der erzeugte Datensatz kann somit auch zur Herstellung eines Replikats im 3D-Druckverfahren genutzt werden. Anhand der Untersuchung der Mandoline von Smorsone wird gezeigt, wie eine CT-Messung durchgeführt wird und wie in dem anschließend rekonstruierten 3D-Datensatz mittels Koordinatenmesstechnik Maße (Abstände, Wandstärken, Winkel) exakt ermittelt werden können.
Im Rahmen von der BAM und anderen Partnern ins Leben gerufene Initiative „Digitale Qualitätsinfrastruktur“ ist der Fokus auf die Entwicklung von neuen Regelwerken und Zertifizierungsworkflows ausgerichtet. Dabei ist eine besondere Bedeutung dem Zusammenführen von Operational Technology (OT) und Informationstechnik (IT) beizumessen, wenn aktuelle Prozess- und Parameterdaten
zuverlässig zur Verfügung gestellt werden sollen. In dem Use Case Wasserstofftankstelle werden digitale Abbilder erprobt, die u.a. der Kalibrierung von Sensoren, dem Nachweis über die Wasserstoffreinheit und der vorausschauenden Wartung dienen sollen.
Großenteils der verfahrenstechnischen Bestandsanlagen, die sogenannten Brownfield-Anlagen, sind nach einem konservativen und hierarchischen Automatisierungskonzept ausgelegt. Hierbei können sämtliche Prozessdaten,
besonders aus der Feldebene, einer oberen informationstechnische Ebene
unzugänglich bleiben. Eine Brückentechnologie nach der NAMUR Open Architecture (NOA) soll möglichst viele Informationen und Daten aus der vorgegebenen Brownfield-Automatisierung sicher und rückwirkungsfrei zur
Verfügung stellen. Zusätzliche Sensorik soll ebenso zu der Datenerweiterung beitragen und letztendlich den digitalen Zwilling, bzw. das digitale Abbild des verfahrenstechnischen Prozesses, ergänzen.
Die Herausforderungen einer solchen Infrastruktur gelten vor allem einer universellen
Kommunikationsschnittstelle und der Sicherheit. Darüber hinaus werden vorgeschlagene Normen und Empfehlungen untersucht und erprobt.
Per- and polyfluorinated alkyl substances (PFASs) are a group of several thousand individual compounds. Many PFASs are extremely persistent, bioaccumulative and toxic. The analysis of PFASs is challenging because of their various chemical and physical properties as well as the high number of compounds. Target-based approaches (e.g., LC-MS/MS) are limited to the availability of analytical grade standards and are not suitable for the analysis of new/unknown PFASs and transformation products. Therefore, PFAS sum parameter methods become increasingly important to indicate realistic PFAS pollution levels.
PFAS sum parameters display the proportion of organically bound fluorine that can either be extracted (EOF) or adsorbed to activated carbon (AOF). For the instrumental analysis of such sum parameters, a fluorine selective detector is needed. High resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) is a sensitive and highly selective tool for fluorine determination. The method is based on the in situ formation of diatomic gallium-mono fluoride (GaF) in a graphite furnace at a temperature of 1550°C. The molecular absorption of GaF can be detected at its most sensitive wavelength at 211.248 nm providing limits of quantification of c(F) 2.7 µg/L.
In the present work a HR-CS-GFMAS method for EOF analysis was utilized for suspended particulate matter (SPM) analysis in German rivers in time lines from 2005–2020. Therefore, time and spatial resolved trends were investigated. In addition, SPM samples were analyzed for the Σ41PFAS using target analysis based on UHPLC-HRMS. Overall, target analysis drastically underestimated the total PFAS burden in SPM of German rivers compared to the EOF HR-CS-GFMAS analysis. Using a fluorine mass balance approach, only 0.2% to 38.6% of the EOF was explainable using the Σ41PFAS determined with target analysis. Our study highlights the need to integrate PFAS sum parameters (e.g., EOF with HR-CS-GFMAS) in PFAS risk assessment strategies.
The isotopic analysis of lithium is also relevant to the study of geological phenomena.1 In this work we propose improvements to the method for the isotopic analysis of lithium using a high-resolution continuum source atomic absorption spectrometer (HR-CS-AAS) coupled to a double echelle modular spectrometer (DEMON). 2 This tool for isotopic ratio determination is based on monitoring the isotopic components of lithium by their spin-orbit coupling and its isotopic shift of about 15 pm for the 22P←2 2S electronic transition around 670.788 nm. The data analysis was carried out by using a decision-tree-based ensemble machine learning (ML) algorithm. For the training of the algorithm (XGBoost), a set of samples with 6Li isotope amount fractions ranging from 0.06 to 0.99 mol-1 was used. Subsequently, the procedure was validated of a set of stock chemicals (Li2CO3, LiNO3, LiCl and LiOH) and a BAM candidate reference material, the cathode material LiNi1/3Mn1/3Co1/3O2 (NMC111). Finally, the ML model was applied to the set of geological samples, previously digested, for the determination of their isotope ratio. The optical resolution was improved from 140,000 to 790,000 to better deconvolution the lithium isotopic components in the atomic spectrum. And the method was compared with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The results are metrologically comparable.
Screening against ADAMTS4 reveals a specific peptide, which was turned into an MRI probe. The aneurysm in a mouse modal was visualized via MRI. A differentiation between stable and unstable aneurysm in an early state was performed. Using the probe as tool for an easy and non-invasive rupture assessment is possible.
Aroma Sensing of Truffles
(2022)
The aim of this project is to develop a mobile technical device to search for truffles. This way, truffles can be harvested faster, cheaper and more efficiently compared to the current method using dogs.
For this purpose, suitable marker substances in the aroma of ripe truffles were identified using analytical-chemical methods. The collected data was used to create aroma profiles of different truffle species.
The specificity of possible marker substances was confirmed with a truffle dog study. The hypothesis “If trained truffle dogs recognize the substances as supposed truffles in the context of an experiment, they can be regarded as specific” was made. The results show that the truffle aroma is mainly characterized and perceived by dogs by dimethyl sulfide and dimethyl disulfide.
For the concentration measurement of these markers in the ambient air, we are currently building our own detector. The Challenge is to get a fast measurement with a very low limit of detection at the same time. The device will resemble a metal detector in terms of shape and handling and be particularly suitable for mobile use.
The R&D cooperation project between the Federal Institute for Materials Research and Testing (BAM) and sglux GmbH thus enables truffles to be harvested professionally and systematically. This brings the technical advances that have revolutionized agriculture over the last hundred years to truffle cultivation for the first time.
Our aim is to develop a simple and inexpensive method for full field X-ray fluorescence imaging.We combine an energydispersive array detector with a coded aperture to obtain high resolut ion images. To obtain the information from the recorded image a reconstruction step is necessary. The reconstruction methods we have developed, were tested on simulated data and then applied to experimental data. The first tests were carried out at the BAMline @BESSY II. This method enables the simultaneous detection of multiple elements,which is important e.g. in the field of catalysis.
With the development of hybridoma technology, monoclonal antibodies are increasingly important in therapeutic and analytical applications. For recombinant expression in mammalian cells, knowledge of the variable regions of both, heavy (VH) and light (VL) chain, is a necessary prerequisite for generating expression plasmids. Furthermore, cloning antibody sequences including constant regions CH1 to CH3 and CL reduces impact of hybridoma cell loss and associated full natural antibody sequence leakage. Here, we show a cost-effective workflow for amplification of IgG antibody variable regions in combination with advanced methods for full-length cloning of monoclonal antibodies.
Compositionally complex alloys (CCAs) are a new class of alloys containing at least 5 elements with concentrations between 5 and 35 atomic percent. Due to their adjustable composition, which enables modifications of mechanical properties (such as hardness, strength and ductility etc) and their stability at high temperatures, CCAs have been the focus of various studies [1,2]. Especially the corrosion behavior of CCAs has been a wide research interest.
However, there are only few studies that deals with the degradation process on such materials, which is highly relevant for the safety aspect for future component design. To thoroughly investigate the corrosion processes and to determine oxidation states of metal components within the reaction products, we need special analytical tools. Since the grazing exit X-ray fluorescence (GEXRF) offers a non-destructive way to collect notable information regarding the high temperature oxidation, we consider it as a useful method to investigate how CCAs behave in corrosive environments.
The main idea of grazing geometry is to enhance the fluorescence signal of the surface. This enables highly sensitive surface analyses of thin protective film on surface in sub-micrometer scale [3]. When compared to a conventional CCD-based camera, the advantage and most important feature of the detector system (Color X-Ray Camera (CXC)) is that each pixel is an energy sensitive detector. The position and area sensitive detector, with 264x264 pixel detector area, provides information regarding the signal emitted from the sample as a function of the emission angle and thus allows depth-sensitive analysis. Furthermore, the data collected from samples of an incidence energy which can be controlled with a resolution of 0.5 eV provides XANES data to determine oxidation states.
In this contribution, we address the feasibility of our setup and new optimization procedure (Bayesian Optimization and Gaussian Regression). The results of a conceptual study regarding layer properties of the reference sample (Cr-Oxide layer (300nm) on Cr layer (500nm) on Si wafer) and CrCoNi (Cr-Oxide (>1µm) layer on CrCoNi substrate) medium entropy alloy.
Getting more efficient – The use of Bayesian optimization and Gaussian processes at the BAMline
(2022)
For more than 20 years, BAM is operating the BAMline at the synchrotron BESSY II in Berlin Adlershof. During this time, the complexity of the setup and the amount of data generated have multiplied. To increase the effectiveness and in preparation for BESSY III, algorithms from the field of machine learning are increasingly used.
After a short introduction to BO and GP, the first example is the automatic alignment of our double multilayer monochromator (DMM).
The second example is the optimization of measurement time in XRF scanning.
Fumonisins are a class of toxic secondary metabolites produced by various Fusarium species. The two most important producers of fumonisins are F. verticillioides and F. proliferatum but also Aspergillus niger is known to produce fumonisins. Most frequently they occur on maize, but also other grains can be contaminated with this group of mycotoxins. Exposure to fumonisins by dietary intake can have serious health effects on farm animals such as equine leukoencephalomalacia and porcine pulmonary oedema and is associated with neural tube defects and esophageal cancer in humans. Thus, the European Commission sets legal limits for fumonisins in foodstuffs. The detection of fumonisins is frequently performed in laboratories by chromatographic methods, which are costly and require trained personnel. Simplifying the analysis is therefore a major goal using portable detection systems. Electrochemical enzymatic biosensors offer great promise to meet this demand. Here we report for the first time an enzymatic fumonisin sensing approach with amperometric detection. For this purpose, an Aspergillus niger fumonisin amine oxidase (AnFAO) catalyzing the oxidative deamination of fumonisins, producing hydrogen peroxide, was recombinantly produced in E. coli. For the first time, the specific enzyme activity of AnFAO was determined using a horseradish peroxidase-based fluorescence assay. It was found that the specific activity of AnFAO using 20 μM Fumonisin B1 as substrate is higher than for 20 μM Fumonisin B2 with 0.122 U mg-1 and 0.058 U mg-1, respectively. It was possible to show a dependence of enzyme activity with enzyme – and substrate-concentration. For fumonisin B1 detection, the enzyme was coupled covalently to magnetic particles and the enzymatically produced H2O2 was detected amperometrically in a flow injection system using Prussian blue carbon electrodes. The developed method allows to quantify fumonisin B1 concentrations down to 1.5 µM and demonstrates that the recombinantly produced AnFAO was able to deaminate different concentrations of fumonisin even in immobilized form. Thus, this enzyme is well suited to develop an enzyme based electrochemical biosensor for fumonisin contaminated food and feed.
Safe food is a prerequisite for good human health, however currently almost one in ten people in the world fall ill after eating contaminated food. National food safety authorities need to be able to manage food safety risks along the entire food chain. The Official Controls Regulation (EU) 2017/625 was put in place to ensure that food and feed law stipulates the need for validated analytical methods. However, whilst method development for food control and proficiency testing are well established by European Union Reference Laboratories and National Reference Laboratories, validation of the measurements involved, certified reference materials and internationally recognised calibration and measurement capabilities are currently often (?) lacking. This may erode trust in the accuracy of the measurements.
This poster presents Food-MetNet, a coordinated preparatory initiative to establish the European Metrology Network for Safe and Sustainable Food, recently approved by the European Association of National Metrology Institutes (EURAMET). Food-MetNet aims to establish an ongoing dialogue between the metrology community, reference laboratories and regulatory bodies, in order to (i) identify stakeholders’ needs, (ii) develop a sustainable knowledge-sharing programme and web-based platform for stakeholders and (iii) develop roadmaps and a strategic research agenda. Improved access to more reliable and accurate food safety measurements will enable reference laboratories to more confidently and effectively compare their measurement results and support accreditation. This is particularly important where national food safety authorities need to assess potential new contaminants, novel food ingredients and newly emerging food risks, and new measurements methods may be required as well as input into new documentary standards. The activities for sustainable food intend to boost the activity within the "EU green deal framework" to reduce food waste and losses, and the development of standards and methods that allow for the reuse of food waste. The support to new business opportunities and innovation will allow increasing the market competitiveness of EU food industries and the valorisation of waste by reducing environmental impacts.
The availability of high-performance Al alloys in AM is limited due to difficulties in printability, requiring both the development of synergetic material and AM process to mitigate problems such as solidification cracking during laser powder bed fusion (LPBF). The goal of this work was to investigate the failure mechanism in a LPBF 7017 Aluminium alloy + 3 wt% Zr + 0.5 wt% TiC. The processing leads to different categories of Zr-rich inclusions, precipitates and defects.
The use of renewable energy sources, electromobility, and portable
electronics relies on lithium-ion batteries (LIBs). However, one
detrimental effect, which can result in significant performance loss,
is the corrosion of the current collectors caused by the aging
mechanisms, especially in high-energy-density batteries
Glow discharge optical emission spectroscopy (GD-OES) provides
depth profile analysis through sputtering using argon plasma, which
enables the analysis of the corrosion behavior at different depths of
the cathodes.
Compact NMR Spectroscopy in the field: A Versatile PAT Tool for Production of Specialty Chemicals
(2022)
Companies of chemical industry find themselves more often in a rapidly changing environment, e.g., due to variability of raw material quality or energy costs and efficiency. Process optimization and new process concepts become more and more important. For example, flexible and modular chemical plants can produce various high-quality products using multi-purpose equipment with short downtimes between campaigns and reduce time to market for new products. Intensified continuous production plants allow for difficult to produce compounds like exothermic reactions with high heat dissipation.
Therefore, fully automated “chemical” process control along with real-time quality control are prerequisites to such concepts and thus should be based on “chemical” information. A commercially available benchtop NMR spectrometer was integrated to the full requirements of an automated chemical production environment such as explosion safety, field communication, and robust evaluation of sensor data. Field studies in modular and conventional production plant setups show promising results gaining process knowledge for further optimization. NMR appeared as preeminent online analytical method and allow using a modular data analysis approach, which can even serve as reliable reference method for further calibration-dependent PAT applications (e.g., NIR spectroscopy). Based on experiences from these field studies an improved analyzer enclosure setup was developed and built, including the option of a secondary method besides NMR spectroscopy. Integrated control systems allow for a flexible implementation based on the available automation infrastructure at the chemical plant or pilot plant setup. In the future, fully integrated and intelligently interconnecting “smart” PAT systems and processes have the potential speed up the setup of production equipment for chemicals and pharmaceuticals and therefore help to reduce the time-to-market.
The majority of ultrasonic devices used for non-destructive testing in civil engineering require contact with the surface of the concrete (specimen), which significantly increases the time required for the measurement. This makes it impractical for extensive investigation of large-scale structures such as bridge decks, foundations, or tunnels.
In a pioneering approach, fluidic oscillators are used as contact
free ultrasonic sources to overcome the aforementioned limitations. These robust and cost-effective actuators require only pressurised air and are ideally suited for harsh environments. At a constant supply pressure, they generate a continuous monofrequent actuation signal. Further, varying the supply pressure via a fast pressure regulator was found to generate a frequency modulated signal which enabled time-of-flight measurement with an added advantage of increased signal to noise ratio. To demonstrate the feasibility of this novel idea of non-contact ultrasound, the results of the initial tests are presented.
High demand for remote sensing of hazardous substances. Possible solution: Use of distributed, low cost, and environmentally safe particles as passive sensors that can be read out remotely
Chemical intelligence on the particle surface can be easily modified Particles enable optically quantifiable response and inference of target substances (also no maintenance or power supply required
Contamination of the environment with antibiotics is of great concern as it promotes the evolution of antimicrobial resistances. In case of amoxicillin (AMX) in the aquatic environment, further risk arises from hydrolysis products (HPs) which can cause allergy. To assess these risks, a comprehensive investigation and understanding of the degradation of AMX is necessary. We investigated the hydrolysis rate of AMX in different types of water as well as the influence of temperature and irradiation. The content of the heavy metal ions copper and zinc was found to be crucial for the hydrolysis rate of AMX and stability of HPs. Eventually, a new degradation pathway for AMX could be elaborated and confirmed by tandem mass spectrometry (LC-MS/MS).
Bei der simulationsunterstützten Planung kritischer Ultraschallprüfaufgaben ist die detaillierte Kenntnis der Parameter der eingesetzten Prüfköpfe von entscheidender Bedeutung. Durch die, in den Regelwerken (DIN EN ISO 22232-2) zugelassenen Toleranzen bei der Herstellung der Prüfköpfe sind einige Prüfkopfparameter nur ungefähr bekannt. Durch die Alterung von Prüfköpfen und Verschleiß können auch Parameter variieren, die nicht vollständig durch die erforderliche Justierung ausgeglichen werden können. Daher sind zusätzlichen Vorversuche oft unvermeidlich. In dieser Arbeit wurden nach einer statistischen Versuchsplanung (DoE) Untersuchungen zur relativen Echo-Empfindlichkeit von konventionellen Prüfköpfen durchgeführt. Die Auswertung wurde für prüfkopfbezogene und personenbezogene Stichproben durchgeführt. Es wird gezeigt, wie weit die Daten um den Zentralwert herum verteilt sind bzw. wie sehr sich das Testobjekt im untersuchten Merkmal unterscheidet. Gerade in Hinblick auf die Beurteilung der intrinsischen Fähigkeit von Prüfverfahren und der Human Factors wird das POD-Analysekonzept zur quantitativen Bewertung der Zuverlässigkeit weiterentwickelt. Die HF-Quantifizierung bezieht sich auf verschiedene Faktoren und Methoden, die in der Veröffentlichung von M. Bertovic et al. [1] ausführlich beschrieben wurden. Die Schritte, die für das Bewertungsverfahren zur POD-Analyse erforderlich sind, werden in der Veröffentlichung von D. Kanzler et al. [2] detailliert dargestellt. Die grundlegenden Anforderungen an die Testkörpersätze für die POD-Analyse wurden in der Publikation von A. Jüngert et al. [3] zusammengefasst. Diesbezüglich wurden mit Hilfe von Simulationsrechnungen die möglichen Abweichungen an Beispielen der im Projekt norm- POD ausgewählten Prüfanordnungen dargestellt. Die Ergebnisse wurden Messungen an Testkörpern gegenübergestellt.
Direct laser writing grows to an industry-ready manufacturing platform. A stable quality infrastructure is needed for robust processing. However, flaws, errors or impurities are neither described nor communicated in the community of two-photon polymerization.
In contrast, additive manufacturing errors in metals manufacturing are described thoroughly.
Compact NMR Spectroscopy in the field: A Versatile PAT Tool for Production of Specialty Chemicals
(2022)
Chemical companies must find new paths to successfully survive in a changing environment, especially by utilizing the potential of digital technologies. Flexible and modular chemical plants can produce various high-quality products using multi-purpose equipment with short downtimes between campaigns and reduce time to market for new products.
Therefore, fully automated process control along with real-time quality control are prerequisites to such concepts and thus should be based on “chemical” information. A commercially available benchtop NMR spectrometer was integrated to the full requirements of chemical production environment such as explosion safety, field communication, and robust evaluation of sensor data. It was used for direct loop advanced process control and real-time optimization of the process. Field studies in modular and conventional production plants show promising results gaining process knowledge. NMR appeared as preeminent online analytical method and allow using a modular data analysis tool, which even served as reliable reference method for further PAT applications (e.g. NIR spectroscopy). In the future, fully integrated and interconnecting “smart” systems and processes can speed up the high-quality production of specialty chemicals and pharmaceuticals.
Compact NMR Spectroscopy in the field: A Versatile PAT Tool for Production of Specialty Chemicals
(2022)
Chemical companies must find new paths to successfully survive in a changing environment, especially by utilizing the potential of digital technologies. Flexible and modular chemical plants can produce various high-quality products using multi-purpose equipment with short downtimes between campaigns and reduce time to market for new products.
Therefore, fully automated process control along with real-time quality control are prerequisites to such concepts and thus should be based on “chemical” information. A commercially available benchtop NMR spectrometer was integrated to the full requirements of chemical production environment such as explosion safety, field communication, and robust evaluation of sensor data. It was used for direct loop advanced process control and real-time optimization of the process. Field studies in modular and conventional production plants show promising results gaining process knowledge. NMR appeared as preeminent online analytical method and allow using a modular data analysis tool, which even served as reliable reference method for further PAT applications (e.g. NIR spectroscopy). In the future, fully integrated and interconnecting “smart” systems and processes can speed up the high-quality production of specialty chemicals and pharmaceuticals.
Micro-(nano-)encapsulation technology involves building a barrier between the core and the environment and offers several benefits to preserve the functional and physicochemical properties of core material. Tremendous progress has been made in synthesizing well-defined capsules to achieve desired properties such as particle size, chemical composition, and controlled release of loaded compounds.
Encapsulation of volatile organic compounds (VOCs) that could evaporate with a defined rate is of immense interest for application in emission reference materials (ERM). These are urgently needed for quality assurance and quality control purposes (QA/QC) required by test standards for the determination of chemical emissions of construction and other materials for interior use. As such ERMs are hardly available on the market, the EU-funded EMPIR project MetrIAQ was started to fill this gap by developing a material with temporally constant emission of VOCs typically found in indoor air.
Luminescence techniques are amongst the most commonly used analytical methods in the life and material sciences due to their high sensitivity and non-destructive and multiparametric character. Photoluminescence signals are, however, affected by wavelength-, polarization-, and time-dependent instrument specific effect and the compound-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements, while the relative determination of the latter requires suitable quantum yield standards with well-known photoluminescence quantum yields (QY). For the simple correction of instrument specific effects in the wavelength region of 300 nm to 950 nm, the set of the five certified spectral fluorescence standards BAM-F001 – BAM-F005, has been extended to the NIR range by including two new fluorescence standards currently under certification. For the reliable and accurate determination of QY which is the key performance parameter for the comparison of different luminophores, we certified a set of 12 quantum yield standards, which absorb and emit in the wavelength range from 300 nm to 1000 nm.
The Sharp GP2Y1010AU0F is a widely used low-cost dust sensor, but despite its popularity, the manufacturer provides little information on the sensor. We installed 16 sensing nodes with Sharp dust sensors in a hot rolling mill of a steel factory. Our analysis shows a clear correlation between sensor drift and accumulated production of the steel factory. An eye should be kept on the long-term drift of the sensors to prevent early saturation. Two of 16 sensors experienced full saturation, each after around eight and ten months of operation.