Analytische Chemie
Filtern
Erscheinungsjahr
- 2017 (193) (entfernen)
Dokumenttyp
- Posterpräsentation (193) (entfernen)
Sprache
- Englisch (169)
- Deutsch (23)
- Mehrsprachig (1)
Schlagworte
- Nanoparticles (14)
- Online NMR spectroscopy (10)
- XPS (9)
- CONSENS (8)
- In situ (7)
- LIBS (7)
- Nanoparticle (7)
- Fluorescence (6)
- Online NMR Spectroscopy (6)
- Process analytical technology (6)
- SEM/EDX (6)
- Thermoresponsive polymers (6)
- Mechanochemistry (5)
- Process Monitoring (5)
- ToF-SIMS (5)
- Boden (4)
- DNA (4)
- Electrochemistry (4)
- Indirect Hard Modeling (4)
- Knoevenagel condensation (4)
- NEXAFS (4)
- Nährstoffe (4)
- Process control (4)
- SEM (4)
- Bridge monitoring (3)
- C-C coupling (3)
- Dosimetry (3)
- Electrospray deposition (3)
- Flourescence (3)
- Functionalization (3)
- Graphene (3)
- Graphite furnace (3)
- High-Resolution Continuum Source Molecular Absorption Spectrometry (3)
- Imaging (3)
- Immunoassay (3)
- Indirect hard modeling (3)
- Isotopic shift (3)
- LA-ICP-MS (3)
- Localization of gas sources (3)
- MALDI-TOF MS (3)
- Mobile Robot Olfaction (3)
- Mycotoxin (3)
- PCA (3)
- Pollen (3)
- Reaction monitoring (3)
- SAXS (3)
- SMASH (3)
- Soil (3)
- Spectral modeling (3)
- TEM (3)
- Tomographic reconstruction of gas plumes (3)
- Tunable Diode Laser Absorption Spectroscopy (TDLAS) (3)
- Upconversion (3)
- XRD (3)
- Zerstörungsfreie Prüfung (3)
- Additive manufacturing (2)
- Air quality monitoring (2)
- Aktive Thermografie (2)
- Ammonia gas sensor (2)
- Analyse (2)
- Auger Electron Spectroscopy (2)
- Bead-based assay (2)
- Biofilms (2)
- Boron isotopes (2)
- Catalysis (2)
- Cement (2)
- Chemometrics (2)
- Click chemistry (2)
- Concrete (2)
- Conductive carbon tape (2)
- Core-shell nanoparticles (2)
- Core-shell particles (2)
- Data analysis (2)
- Elastic wave velocity (2)
- Electron microscopy (2)
- Flow cytometry (2)
- Fluorine (2)
- Food (2)
- HR-CS-MAS (2)
- Hepcidin-25 (2)
- Intercalibration (2)
- Isotope ratio (2)
- Isotope reference material (2)
- LC-MS/MS (2)
- Laser ablation (2)
- Mass spectrometry (2)
- Materialcharakterisierung (2)
- Microdosimetry (2)
- Molecular absorption (2)
- Multivariat (2)
- Mycotoxins (2)
- Nanomaterial classification (2)
- Nanoplatelets (2)
- Natural Zeolite Clinoptilolite (2)
- Online reaction monitoring (2)
- Perovskite (2)
- Process Analytical Technology (2)
- Prüfung (2)
- Quantum dot (2)
- RFA (2)
- RFID sensors (2)
- Radiation damage (2)
- Reinheitsgradbestimmung (2)
- Resonant mass measurement (2)
- Reverse glass painting (2)
- Rotaxane (2)
- Semiconductor (2)
- Sensors in concrete (2)
- Silver nanoparticles (2)
- Single particle spectroscopy (2)
- Solar cells (2)
- Spectroscopy (2)
- Standard gas generator (2)
- Superplasticizers (2)
- Surface analysis (2)
- Thin films (2)
- Titania (2)
- UAV-REGAS (2)
- Ultraschall (2)
- Ultraschalltauchtechnik (2)
- Wirbelstromprüfung (2)
- X-ray refraction (2)
- XRF (2)
- 3-axis gimbal (1)
- 3D (1)
- 3D High-temperatue shape screening (1)
- 3D-Printing (1)
- 87Sr/86Sr (1)
- AES (1)
- Ablaufdiagramme (1)
- Absolute flourometry (1)
- Acrylamide based polymers (1)
- Active thermography (1)
- Additive Fertigung (1)
- Additive Manufacturing (1)
- Adsorbentien (1)
- Adsorption (1)
- Aerial platform (1)
- Aerial systems (1)
- Agglomeration (1)
- Agriculture (1)
- Alginate (1)
- Alkali-silica-reaction (ASR) (1)
- Alkaline earth metal (1)
- Aluminum (1)
- Ambient ionization (1)
- Ambient noise (1)
- Ammonia (1)
- Analytical method (1)
- Annealing study (1)
- Anthropogenic markers (1)
- Antibody (1)
- Artificial digestion (1)
- Auger electron spectroscopy (1)
- BET (1)
- BFR (1)
- Bacterial Extracellular Electron Transfer Mechanisms (1)
- Bead based assay (1)
- Beton (1)
- Beton Ultraschall Monitoring (1)
- Biocorrosion (1)
- Bioimaging (1)
- Biomolecules (1)
- Boron monohydride (1)
- Brown-rot fungi (1)
- C Kedge NEXAFS (1)
- CFK (1)
- CO2 assisted impregnation (1)
- CO2 reduction (1)
- Cable-suspended parallel manipulator (1)
- Calcined clay (1)
- Capsules (1)
- Carboxy and amin (1)
- CdSe (1)
- Cearmics (1)
- Cell (1)
- Cellular uptake (1)
- Cement hydration (1)
- Certified reference materials (1)
- Chemical reaction (1)
- Chlorpyrifos (1)
- Citrinin (1)
- Coating (1)
- Cocrystal (1)
- Coda wave interferometry (1)
- Composites (1)
- Coordination polymer (1)
- Core-shell architecture (1)
- Core/Shell/Shell (1)
- Core/shell/shell (1)
- Corosion (1)
- Coulometric sensors (1)
- Crack detection (1)
- Cracks (1)
- Crystallization (1)
- Cyclohexane (1)
- Damage (1)
- Data Analysis (1)
- Data processig (1)
- Delta values (1)
- Depth profiling (1)
- Depth-profiling (1)
- Direct fluorine-metal bond (1)
- Direct loop control (1)
- Discotic Liquid Crystals (1)
- Dispersive (1)
- Doping study (1)
- Dyes (1)
- EC definition of a nanomaterial (1)
- EC definition of nanomaterial (1)
- Electrochemical synthesis (1)
- Electrodeposited Ni - coatings (1)
- Electron irradiation (1)
- Electron micrsocopy (1)
- Electronic nose (1)
- Embedded sensors (1)
- Embedded transducers (1)
- Emerging pollutants (1)
- Emerging technologies (1)
- Emissions testing (1)
- Energy resolved XPS (1)
- Environment (1)
- Environment monitoring and management (1)
- Environmental analysis (1)
- Epitope analysis (1)
- Er(III) (1)
- EuroPACT (1)
- Explosion Safety (1)
- FTIR (1)
- FeSnOx (1)
- Ferroelektret (1)
- Fertility management (1)
- Field Integration (1)
- Field robots (1)
- Flow cell (1)
- Flow-cytometry (1)
- Flowcytometry (1)
- Fluorescence materials (1)
- Fluorescence reference materials (1)
- Fluorescence sensors (1)
- Fluoride (1)
- Fontainebleau Sandstein (1)
- Food safety (1)
- Fundamente (1)
- Gas detection (1)
- Gas metrology (1)
- Gas sensing (1)
- Gas sensor (1)
- Gas sensors (1)
- Gas standard generator (1)
- Gassensing (1)
- Geant4 (1)
- Glass composition (1)
- Glass conservation (1)
- Glass-based fluorescence standard (1)
- Graphene 2D nanomaterial (1)
- Grundwasser (1)
- Haftfestigkeit (1)
- Hydride (1)
- Hydroformylation (1)
- Hydrogenation (1)
- Hydroxyl radicals (1)
- ICP-MS (1)
- Iisotope reference materials (1)
- Illite (1)
- Immobilization (1)
- Impuls-Thermografie (1)
- In-situ measurement (1)
- InPROMPT (1)
- Industrie 4.0 (1)
- Inhibition of HSV virus (1)
- Ink (1)
- Instrumented indentation testing (1)
- Integrating sphere spectroscopy (1)
- Interferometry (1)
- Iron biomarker (1)
- Isotope fractionation (1)
- Isotopes (1)
- Kaolinite (1)
- Keramikdurchflusszelle (1)
- KonSens (1)
- LC-MS/MS quantification (1)
- LC/MS (1)
- LCST (1)
- LEE (1)
- Labeling (1)
- Laser induced plasma (1)
- Laser profilometry (1)
- Laser-spark (1)
- Layer analysis (1)
- Layer analytics (1)
- Life sciences (1)
- Lifetime (1)
- Lifetime encoding (1)
- Line prediction (1)
- Liquefied petroleum gas (1)
- Lock-in-Thermografie (1)
- Long-term requirements (1)
- Low-Field NMR spectroscopy (1)
- Luftultraschall (1)
- Luminescence (1)
- MVA (1)
- Magnesium delta scale (1)
- Magnesium delta value (1)
- Magnesium isotope (1)
- Magnesium isotope ratio (1)
- Magnesium stable isotopes (1)
- Magnetostrictive actuator layer (1)
- Magnetostrictive layer (1)
- Magnetron sputtering (1)
- Malodour detection (1)
- Manuscript (1)
- Mapping (1)
- Mass Spectrometry (1)
- Matrix (1)
- Mechanochemical syntheses (1)
- Medieval glass composition (1)
- Medieval stained glass (1)
- Mehr-Proben-Kleben (MSB) (1)
- Mehr-Proben-Prüfen (CAT) (1)
- Memory effect (1)
- Metal hydrides (1)
- Metal organic frameworks (1)
- Metal phosphonate (1)
- Metrology (1)
- Micro-XRF (1)
- Micro-heterogeneity (1)
- Microbiological investigation (1)
- Microbiology (1)
- Microwave synthesis (1)
- Milling (1)
- Mini-plant (1)
- Miniaturized sensor device (1)
- Minitaurized sensor device (1)
- Mobile robot olfaction (1)
- Mobile sensors (1)
- Modular production plants (1)
- Modularised production (1)
- Moisture monitoring (1)
- Molecular dynamic simulation (1)
- Monte-Carlo simulation (1)
- Multi sensor device (1)
- Multi-element (1)
- Multicopter (1)
- Multivariate (1)
- NAP-XPS (1)
- NBT (1)
- NBT-Piezoceramics (1)
- NIR (1)
- NSO-Heterocyclen (1)
- Nanocluster (1)
- Nanomaterial classfication (1)
- Nanoparticles separation capillary electrophoresis asymmetrcial flow field flow fractionation (1)
- Natural zeolite clinoptilolite (1)
- Niederfeld-NMR (1)
- Niederfeld-NMR-Spektroskopie (1)
- Nominal properties (1)
- Normung (1)
- Nuclear Magnetic Resonance (1)
- Numerical methods (1)
- OH radicals (1)
- OPC UA (1)
- Olfaction (1)
- Online NMR Spektroskopie (1)
- Online monitoring (1)
- Online-NMR (1)
- Optical assays (1)
- Optical spectroscopy (1)
- Oxidation (1)
- PAT (1)
- PDMS (1)
- PLSR (1)
- PNA (1)
- PS (1)
- PTFE (1)
- PVD /ECD process (1)
- Pair distribution function analysis (1)
- Particle sizing techniques (1)
- Passive RFID (1)
- Passive Seismics (1)
- Passive seismics (1)
- Passive sensors (1)
- Passivsammler (1)
- Pattern recognition methods (1)
- Peptide losses (1)
- Perception and autonomy (1)
- Permeation method (1)
- Photoreaction (1)
- Photothermal (1)
- Piezoceramics (1)
- Pigments (1)
- Planung (1)
- Polymer blends (1)
- Polymer particles (1)
- Polymeric material (1)
- Polymers (1)
- Polymers based on 2,6-diaminopyridine (1)
- Polymorph (1)
- Polymorphism (1)
- Porosity (1)
- Powder (1)
- Precision (1)
- Prehydrated electrons (1)
- Process monitoring (1)
- Process sensors (1)
- Protein (1)
- Protein coating (1)
- Provenance (1)
- Prozessanalytik (1)
- Pump control (1)
- QD (1)
- Qualitative RM (1)
- Quantitative NMR spectroscopy (1)
- Quantum yield (1)
- Quantum yield standard (1)
- RFID based sensors (1)
- RNA detection (1)
- Radiation protection (1)
- Raman spectroscopy (1)
- Reduction 4-nitrophenol (1)
- Reference material (1)
- Residual stress (1)
- Response behavior (1)
- Reverse Time Migration (1)
- Riss (1)
- Rotaxanes (1)
- SAFT (1)
- SEM analysis (1)
- SEM-EDX (1)
- SERS (1)
- SP-ICP-MS (1)
- SPR (1)
- STXM (1)
- Sample preparation (1)
- Sample pretreatment (1)
- Sandstone (1)
- Schienenschleifen (1)
- Selective laser melting (1)
- Self-healing (1)
- Sensing (1)
- Sensor (1)
- Sensor requirements (1)
- Sensors (1)
- Shape (1)
- Shell (1)
- Silanization (1)
- Sintering (1)
- Site-specific (1)
- Size (1)
- Size effect (1)
- Small-angle scattering (1)
- Smart sensors (1)
- Smart structures (1)
- Smectite (1)
- Spectral Modeling (1)
- Spectral multiplexing (1)
- Spectroelectrochemical Techniques (1)
- Spektral Induzierte Polarisation (1)
- Standardization (1)
- Standards (1)
- Steel (1)
- Strain sensors (1)
- Strontiumfluoride (1)
- Structural health monitoring (1)
- Structured heating (1)
- Substrate effect (1)
- Substrates (1)
- Supplementary cementitious materials (1)
- Surface Enhanced Raman Spectroscopy (1)
- Surface Plasmon Resonance (1)
- Surface characterization (1)
- Surface chemistry (1)
- Surface groups (1)
- Surface modification (1)
- Synchrotron (1)
- Synchrotron X-ray diffraction (1)
- Synchrotron-XPS (1)
- Synthesis (1)
- Synthetic organic pigments (1)
- TEM grids (1)
- THz-time-domain spectroscopy (1)
- Tandem MS (1)
- Technological innovation (1)
- Tempeh (1)
- Temperature influence (1)
- Termites (1)
- Ternary quantum dot (1)
- Thermal cycling (1)
- Thermal wave (1)
- Thermografie (1)
- Thiol-ene coupling (1)
- TiO2 (1)
- Tiered approach (1)
- Time-gate Raman (1)
- Time-resolved (1)
- Tomography (1)
- Trace humidity measurement (1)
- Traceability (1)
- Transformation Products (1)
- Trophic level (1)
- UAV (1)
- UCST polymers (1)
- UCST-type copolymer (1)
- UCST-type polymers (1)
- USCT-type polymers (1)
- Ultraschallprüfung (1)
- Ultrasound (1)
- VOC (1)
- VSSA (1)
- Validation (1)
- Verbundfestigkeit (1)
- Volatile organic compounds (1)
- Wastewater (1)
- Water (1)
- Water transport (1)
- Wiedernutzung (1)
- X-ray computed tomography (CT) (1)
- XAFS (1)
- XANES (1)
- XRF analysis (1)
- Yb(III) (1)
- Zentrifugentechnologie (1)
- Zerstörungfreie Analytik (1)
- Zwitterionic graphene nanomaterials (1)
- low energy electrons (1)
- pH (1)
- µPAD (1)
Leaking methane (CH4) from infrastructures, such as pipelines and landfills, is critical for the environment but can also pose a safety risk. To enable a fast detection and localization of these kind of leaks, we developed a novel robotic platform for aerial remote gas sensing. Spectroscopic measurement methods for remote sensing of selected gases lend themselves for use on mini-copters, which offer a number of advantages for inspection and surveillance over traditional methods. No direct contact with the target gas is needed and thus the influence of the aerial platform on the measured gas plume can be kept to a minimum. This allows to overcome one of the major issues with gas-sensitive mini-copters. On the other hand, remote gas sensors, most prominently Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensors have been too bulky given the payload and energy restrictions of mini-copters. Here, we present the Unmanned Aerial Vehicle for Remote Gas Sensing (UAV-REGAS), which combines a novel lightweight TDLAS sensor with a 3-axis aerial stabilization gimbal for aiming on a versatile hexacopter. The proposed system can be deployed in scenarios that cannot be addressed by currently available robots and thus constitutes a significant step forward for the field of Mobile Robot Olfaction (MRO). It enables tomographic reconstruction of gas plumes and a localization of gas sources. We also present first results showing its performance under realistic conditions.
The ambient air quality around residential areas is influenced by industrial objects, including industrial sewage, livestock farming and landfill sites. These sites are generating malodours or toxic gases involving degradation of ambient air quality, which may constitute a risk in human health if maximum emission limits are exceeded. Therefore, appropriate tools allowing detection of harmful or bad odorous, subsequently contributing to a reduction of odour nuisance are greatly needed. The aim of this study was to demonstrate the capability of an electronic nose E-nose to discriminate various gas samples collected from six different sites from the agglomeration of Meknès city corresponding to municipal landfill, in the city at 2 km of landfill, industrial estate wastewater, traffic road, and sheep breeding. The investigations were carried out with an E-nose system based on an array of six-commercial MQ sensors. Further, a pattern recognition technique known as Principal Component Analysis (PCA), Linear Discriminent Analysis (LDA), and Support Vector Machines (SVMs) was implemented to study the discrimination capability of the sensor array. PCA results demonstrate excellent discriminating ability of the dataset with a score of 99.47 %. Additionally, another measurement database containing 12 air atmospheric samples was projected on the previously built PCA model to check the stability of the E-nose. The LDA was applied to the same dataset and showed a good discrimination between the ambient air samples of the six sites. Furthermore, SVMs technique was also used to build a classifier and reached a score of 100 % success rate in the recognition of the analysed samples. The obtained results of six areas demonstrate the increasing interests and the applicability of E-noses for ambient air quality classification of six areas caused by emitted decomposed organic matters.
The synthesis of TiO2 nanoplatelets with fluorine-containing reactants is carried out using Ti (IV) butoxide as precursor and concentrated HF as shape controller, the final product requires a working up in order to eliminate or at least to reduce the amount of residual fluorides, which is realized here by well-defined thermal treatment.
Qualitative investigation of the bulk elemental composition by means of EDX of TiO2 nanoparticles (NPs) has identified fluorine in case of the as-synthesized samples. EDX spectra of thermally treated products exhibit either a fluorine content close to the limit of detection. The latter holds also true for the reference sample, TiO2 NPs of bipyramidal shape and prepared by a different synthesis route. For differentiation whether fluorine is present in the bulk or at the surface of the TiO2 nanoplatelets, top-surface sensitive AES and ToF-SIMS has been applied. Secondary ions of fluorine are detected in ToF-SIMS spectra of all samples, but could be roughly quantified by measurement of same reference sample as for EDX, namely TiO2 nano-bipyramids. This revealed that the amount of fluorine within1 nm depth beneath the surface is reduced in the thermally treated specimen compared to the raw product down to a content about as low as in the reference sample. AES allows analyzing analysis of the first few nanometers from the top-surface of individual NPs by point analysis. An F KLL peak has been detected at the surface of samples of as-prepared TiO2 nanoplatelets under optimized measurement conditions, but was not detectable after their calcination, which is in agreement with ToF-SIMS results. Moreover, high resolution AES on single TiO2 nanoplatelets elucidated that the surface atomic layers surrounding the TiO2 nanopaltelet contain fluorides before thermal treatment of the NPs.
Hydrothermal synthesis of anatase TiO2 nanosheets with a high fraction of exposed {001} facets and related high photocatalytic activity - as an alternative to bipyramidal anatase TiO2 nanoparticles mainly exposing the {101} facets. The scope of the material preparation work is the thermal reduction of residual fluorides from HF (capping agent) induced during the synthesis of TiO2 nanosheets by calcination at 873K. The analytical task consists of detection and localization of fluorine present at the surface and/or in the bulk of TiO2 nanosheets before and after calcination by SEM/EDX, Auger electron spectroscopy and ToF-SIMS.
Hepcidin-25 has attracted much attention ever since its discovery in 2001. It is widely recognized that this liver produced peptide hormone plays a major role in the regulation of iron levels in mammals and can reveal important clinical information about several pathological states in patients suffering from iron-related disorders.
With the aim to tackle the current difficulties in hepcidin quantification and improve the status of this promising biomarker in the clinical field, we developed a rapid and robust analytical strategy for the quantification of hepcidin-25 in human samples based on HPLC-MS/MS (QqQ) to be implemented in routine laboratories. The novelty of the method is the use of special HPLC vials to avoid adsorptive losses due to the basic character of the peptide that causes interaction with the silanol groups of the vial’s glass surface. Up to 90% decrease in the MS/MS signal was observed, when commercial HPLC vials were used, while vials treated with 3-(2-aminoethylamino)propylmethyl-dimethoxysilane or 1H,1H,2H,2H-perfluorooctyltriethoxysilane, leading to no significant losses in the dynamic range of physiological hepcidin-25 mean serum levels (10-20 µg/L).
Careful analytical validation was performed for determining the reproducibility, repeatability, limit of quantification (0.5 µg/L) and linearity (0.5-40 µg/L) of the method. Serum samples from 9 healthy volunteers were analyzed with a median hepcidin-25 level of 3.3 µg/L, comparable to results reported in the literature.
Anomalous surface composition in thin films of a poly(vinyl methyl ether) / polystyrene blend
(2017)
Highly surface-sensitive X-ray photoelectron spectroscopy at HE-SGM beamline revealed in the outermost region (< 2nm) of thin films (15 -65 nm) of PVME/PS blends a relative high amount of PS, whereas in slightly deeper regions PVME was enriched. Such enrichment of PVME in the whole near-surface region was proposed in former investigations based on conventional XPS studies.
Das Ultraschall-Echo-Verfahren ist eine wichtige Methode der zerstörungsfreien Prüfung (ZfP). Prüfaufgaben im Bauwesen beinhalten unter anderem die korrekte Dickenbestimmung von Konstruktionen, sowie die Lokalisierung von Einbauteilen und Fehlstellen. Das Abbildungsverfahren RTM (Reverse Time Migration) liefert oft bessere Bilder als konventionelle Verfahren. Die Datenaufnahme am Betonprobekörper erfolgte mit einem Scannersystem der BAM, bei dem jeweils ein Ultraschall-Prüfkopf als Sender bzw. Empfänger diente. Es wurden senkrecht zur Profilrichtung horizontal polarisierte Scherwellen genutzt. Die RTM wurde mit dem Softwarepaket Madagascar gerechnet.
Die Ergebnis zeigt das Potential dieser Methode im Bezug auf komplexe Strukturen. Die lateralen Positionen der Risse im RTM-Bild sowie deren Höhe innerhalb des Probekörpers, entsprechen recht genau dem visuellen Befund.
Qualitative reference materials (RM) cover a wide range of the overall RM market. Proficiency testing providers attract up to a thousand of participants in PT schemes purely oriented on qualitative results. The RM used for these kinds of PT are poorly regulated, nevertheless with a more and more general acceptance of accreditation in the field of RM production and PT provision, there is an ever increasing interest in assessing producers and providers according to rules already well accepted in the field of quantitative analysis.
The basic governing document, ISO 17034:2016, is written in a form that, at least for the overwhelming majority of requirements, may be applied to both qualitative and quantitative RM. However, problems remain. In particular, the expression of uncertainty of a purely qualitative result is still unresolved, and under discussion, the latter now lasting already dozens of years.
Some handles would be needed. In the poster, existing approaches and some pragmatic, new ways to tackle the problem are displayed and discussed.
Knowledge about feeding behavior is essential to determine trophic interactions and reconstruct predator-prey relationships in modern and past foodwebs. Traditionally, nitrogen isotopes (δ15N) of collagen are used to quantify the ingestion of animal protein, however collagen usually does not preserve over geological time scales. To infer the diet of extinct vertebrates from fossil material more resistant dietary proxies such as Ca and Mg isotopes are needed, which are major elements in the bioapatite of bones and teeth. Magnesium is a bio-essential element that replaces calcium in the bioapatite lattice and bone and enamel δ26Mg values of extant mammals increase systematically along the foodchain [1, 2].
The existing δ26Mg data, however, is scarce, in particular with respect to carnivores, thus still limiting the capability of this dietary proxy to reliably determine trophic differences between plant- and animal-feeders. To better constrain trophic-level effects recorded in Mg isotopes, we analyzed δ26Mg of bioapatite from modern mammals with a focus on faunivores, both carnivores and as yet unexplored insectivores.
The trophic level effect of δ26Mg is influenced by the geological substrate which causes isotope variability in δ26Mg of faunal remains between different ecosystems [1, 2]. Therefore, as first-order proxy for sample provenance and to assess potential influences of the bedrock substrate of the animals´ habitats on δ26Mg of bones and teeth, we measured the 87Sr/86Sr on the same specimens. This information will enable us to refine trophic level effects and determine whether δ26Mg can be used to distinguish different faunivores isotopically. This will be of paramount importance for dietary reconstructions of trophic niches in fossil foodwebs.
[1] Martin et al. (2014) Geochmica Cosmochimica Acta 130, 12-20. [2] Martin et al. (2015) Proceedings of the National Academy of Sciences 112, 430-435.
Assessment and validation of various flow cell designs for quantitative online NMR spectroscopy
(2017)
Compact nuclear magnetic resonance (NMR) instruments make NMR spectroscopy and relaxometry accessible in industrial and harsh environments for reaction and process control. Robust field integration of NMR systems have to face explosion protection or integration into process control systems with short set-up times. This paves the way for industrial automation in real process environments.
The design of failsafe, temperature and pressure resistant flow through cells along with their NMR-specific requirements is an essential cornerstone to enter industrial production plants and fulfill explosion safety requirements. NMR-specific requirements aim at full quantitative pre-magnetization and acquisition with maximum sensitivity while reducing sample transfer times and dwell-times. All parameters are individually dependent on the applied NMR instrument. Luckily, an increasing number of applications are reported together with an increasing variety of commercial equipment. However, these contributions have to be reviewed thoroughly.
The performance of sample flow cells commonly used in online analytics and especially for low-field NMR spectroscopy was experimentally and theoretically investigated by 1H-NMR experiments and numerical simulations. Here, we demonstrate and discuss an automated test method to determine the critical parameters of flow through cells for quantitative online NMR spectroscopy. The setup is based on randomized setpoints of flow rates in order to reduce temperature related effects. Five flow cells and tubings were assessed and compared for high-field as well as low-field NMR spectrometers.