Chemische Charakterisierung und Spurenanalytik
Filtern
Erscheinungsjahr
- 2018 (66) (entfernen)
Dokumenttyp
- Zeitschriftenartikel (66) (entfernen)
Schlagworte
- Fluorescence (8)
- Laser ablation (5)
- ICP-MS (4)
- Mechanochemistry (4)
- Mass spectrometry (3)
- Mass-Spectrometry (3)
- Nanoparticle (3)
- Quantum yield (3)
- Abwasser (2)
- Bioimaging (2)
- Cells (2)
- Copper (2)
- ELISA (2)
- HRMS (2)
- Immunohistochemistry (2)
- In situ (2)
- LA-ICP-MS (2)
- LC-MS/MS (2)
- Mercury (2)
- Metrology (2)
- Microplastic (2)
- Mobile phase (2)
- Mycotoxin (2)
- Oxygen sensor (2)
- Photodegradation (2)
- Purity (2)
- Purity assessment (2)
- Quantification (2)
- Reference material (2)
- Traceability (2)
- Transformation products (2)
- Tumor metabolism (2)
- XRD (2)
- AG nanoparticle (1)
- ANOVA (1)
- ATCUN (1)
- AU nanoparticle (1)
- Absorption spectrometry (1)
- Adsorption (1)
- Affinity chromatography (1)
- Affinity extraction (1)
- Albumin (1)
- Aluminum (1)
- Amyloid (1)
- Anilinopyridine (1)
- Anion receptors (1)
- Antikensammlung Berlin (1)
- Arsenite (1)
- Aspergillus (1)
- Atomic Force Microscopy (1)
- BLE Bluetooth low energy (1)
- Bakterien (1)
- Barium (1)
- Basic solvent (1)
- Benchtop NMR Spectroscopy (1)
- Big Data (1)
- Bioconjugation (1)
- Biosynthesis (1)
- Biotests (1)
- Biotransformation (1)
- Bisphenol A (1)
- Block copolymer (1)
- CCQM key comparison (1)
- CONSENS (1)
- CRM (1)
- Calcium monofluoride (1)
- Carbodiimide crosslinking (1)
- Cell (1)
- Charge Transfer (1)
- Chemical sensors (1)
- Chemical transformation (1)
- Chicken antibodies (1)
- Chromatography (1)
- Chronic kidney disease (1)
- Classification (1)
- Colorimetric Test (1)
- Complex (1)
- Complexation (1)
- Conjugate (1)
- Coordination polymers (1)
- Core-shell particles (1)
- Coulometric sensors (1)
- Coumarin (1)
- Coupling reactions (1)
- Cr(III) (1)
- Cr(III) complex (1)
- Cyanide (1)
- Cyanide in soil (1)
- Cyclization (1)
- D-glucose (1)
- DC-Arc (1)
- DEA (1)
- DNA (1)
- Datenanalyse (1)
- Datenkonzepte (1)
- Diagnostics (1)
- Diclofenac (1)
- Digitalisierung (1)
- Dimerization (1)
- Dip-stick assay (1)
- Direct metal assay (1)
- Droplets (1)
- Drug transporters (1)
- Dye (1)
- Dyes/pigments (1)
- E. coli (1)
- EC/LC/MS (1)
- EPR spectroscopy (1)
- Ecotoxicity (1)
- Einzelzellanalyse (1)
- Electrochemical oxidation (1)
- Electrochemistry mass spectrometry (1)
- Elektronenmikroskopie (1)
- Emerging/novel brominated flame retardant (1)
- Endocrine disruptor (1)
- Endokrine Disruptoren (1)
- Ethyl glucuronide (1)
- Exposure (1)
- FTIR spectroscopy (1)
- Fatty acid metabolism (1)
- Fe nanoparticles metabolism (1)
- Fenton (1)
- Festphasenextraktion (1)
- Fluorescence lifetime (1)
- Fluorescence sensing (1)
- Fluorine (1)
- Fluxomics (1)
- Folic acid (1)
- Formulation additives (1)
- Fungicide (1)
- Fusarium (1)
- Graphit (1)
- Graphite furnace (1)
- Greek curse tablets (1)
- Group profile (1)
- HPLC (1)
- HPLC-DAD/FLD (1)
- HPLC-ICP-MS (1)
- HPLC-MS (1)
- HPLC–MS (1)
- HR-CS-MAS (1)
- Hierarchical cluster analysis (1)
- High pH (1)
- High purity (1)
- High-purity elements (1)
- Hormone (1)
- ICP-MS/MS (1)
- IDMS (1)
- IgY (1)
- Imaging (1)
- Immunoaffinity extraction (1)
- Immunoassay (1)
- Impurity assessment (1)
- In situ studies (1)
- Indirect Hard Modeling (1)
- Interlaboratory comparison (1)
- Iron Complex (1)
- Iron disorders (1)
- Isotope dilution mass spectrometry (1)
- Isotopic dilution (1)
- Job plot (1)
- Kidney (1)
- Kläranlage (1)
- Konjugate (1)
- Künstlicher Intelligenz (1)
- L-alanine (1)
- LIBS (1)
- Lanthanide (1)
- Laser (1)
- Lead isotopes (1)
- Lebensmittel (1)
- Lifetime (1)
- Ligand design (1)
- Lipidomic profile (1)
- Liquid chromatography (1)
- Low energy electrons (1)
- Luminescence (1)
- Luminescence lifetime (1)
- MALDI Imaging MS (1)
- MALDI-TOF MS (1)
- MALDI-ToF-MS (1)
- MAS NMR spectroscopy (1)
- MYCN (1)
- Magnetic nanocatalyst (1)
- Magnetically stabilized (1)
- Maillard reaction (1)
- Mass-spectrometry (1)
- Matrixeffekte (1)
- Measurement uncertainty (1)
- Measuremment uncertainty (1)
- Mechanochemical synthesis (1)
- Melanoidin (1)
- Melanoidine (1)
- Mesoporous materials (1)
- Metabolic stress (1)
- Metabolism (1)
- Metabolization (1)
- Metal nanoclusters (1)
- Metal nanoparticles (1)
- Metalloprotein (1)
- Metals (1)
- Microfluidics (1)
- Moisture measurements (1)
- Molecular dynamics simulations (1)
- Molecular imprinting (1)
- Molecularly imprinted polymers (1)
- Molecule (1)
- Multimodal (1)
- Multivariate Statistics (1)
- Mycotoxins (1)
- NIR (1)
- NIR emitter (1)
- NMR (1)
- NMR spectroscopy (1)
- Nanocluster (1)
- Nanomaterials (1)
- Nanoparticles (1)
- Nanopartikel (1)
- Nickel (1)
- Non-metal analysis (1)
- Oberflächenwasser (1)
- Online NMR spectroscopy (1)
- Optical emission spectroscopy (1)
- P-aminothiophenol (1)
- PXRD (1)
- Partial Least Squares Regression (1)
- Partial least square discriminant analysis (PLS-DA) (1)
- Pb isotopes (1)
- Peptide (1)
- Peptide analysis (1)
- Peptide library screening (1)
- Peptide losses (1)
- Photodynamische Inaktivierung (1)
- Photokatalyse (1)
- Photosensibilisator (1)
- Phthalocyanin (1)
- Plasma (1)
- Plasma modeling (1)
- Pollen (1)
- Pollen grains (1)
- Polymer membrane (1)
- Polymorphs (1)
- Porphyrin (1)
- Principal component analysis (1)
- Principal component analysis (PCA) (1)
- Probe (1)
- Probenvorbereitung (1)
- Process analytical technology (1)
- Proficiency testing (1)
- Protein imaging (1)
- Prozessindustrie (1)
- Pt-based drugs (1)
- Pulverization (1)
- QC (1)
- Quality control (1)
- R package (1)
- RSSI Received Signal Strength Indicator (1)
- Rational design (1)
- Recovery (1)
- Reference measurements (1)
- Reproducibility (1)
- Rhizopus (1)
- Rhodamine (1)
- Round robin exercise (1)
- SDHI-fungicide (1)
- SI-traceability (1)
- Sample treatment (1)
- Sensor network (1)
- Sers (1)
- Sewage treatment plant (1)
- Silanization (1)
- Silbernanopartikel (1)
- Silver nanoparticles (1)
- Single cell analysis (1)
- Single-cell analysis (1)
- Smart Sensors (1)
- Society of hair testing (1)
- Solid-phase extraction (1)
- Species-unspecific on-line isotope dilution (1)
- Spectroscopy (1)
- Standardization (1)
- Structural Health Monitoring (1)
- Synthesis (1)
- TED-GC-MS (1)
- Test strips (1)
- Thin tissue sections (1)
- Tire wear (1)
- Tissue soldering (1)
- Total cyanide (1)
- Toxicity (1)
- Toxicity testing (1)
- Trace humdity measurement (1)
- Tutzing-Symposion (1)
- Uncertainty (1)
- Validation (1)
- Validierung (1)
- Viscosity (1)
- Xerogel (1)
- Zearalenone (1)
- Zirconium (1)
- Zyklisierung (1)
- pH sensor (1)
- Ägyptisches Museum Berlin (1)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (54)
- 1.1 Anorganische Spurenanalytik (21)
- 6 Materialchemie (17)
- 6.3 Strukturanalytik (14)
- 1.7 Organische Spuren- und Lebensmittelanalytik (13)
- 1.8 Umweltanalytik (9)
- P Präsident (7)
- P.0 Präsident und andere (7)
- 1.9 Chemische und optische Sensorik (6)
- 1.2 Biophotonik (5)
Online immunocapture ICP‑MS for the determination of the metalloprotein ceruloplasmin in human serum
(2018)
The human copper-protein ceruloplasmin (Cp) is the major copper-containing protein in the human body. The accurate determination of Cp is mandatory for the reliable diagnosis of several diseases. However, the analysis of Cp has proven to be difficult. The aim of our work was a proof of concept for the determination of a metalloprotein-based on online immunocapture ICP-MS. The immuno-affinity step is responsible for the enrichment and isolation of the analyte from serum, whereas the compound-independent quantitation with ICP-MS delivers the sensitivity,
precision, and large dynamic range. Off-line ELISA (enzyme-linked immunosorbent assay) was used in parallel to confirm the elution profile of the analyte with a structure-selective method. The total protein elution was observed with the 32S mass trace. The ICP-MS signals were normalized on a 59Co signal. The human copper-protein Cp could be selectively determined. This was shown with pure Cp and with a sample of human serum. The good correlation with off-line ELISA shows that Cp could be captured and eluted selectively from the anti-Cp affinity column and subsequently determined by the copper signal of ICP-MS.
Biotransformation processes of fluopyram (FLP), a new succinate dehydrogenase inhibitor (SDHI) fungicide, were investigated by electrochemistry (EC) coupled online to liquid chromatography (LC) and electrospray mass spectrometry (ESI-MS). Oxidative phase I metabolite production was achieved using an electrochemical flow-through cell equipped with a boron doped diamond (BDD) electrode. Structural elucidation and prediction of oxidative metabolism pathways were assured by retention time, isotopic patterns, fragmentation, and accurate mass measurements using EC/LC/MS, LC-MS/MS, and/or high resolution mass spectrometry (HRMS). The results obtained by EC were compared with conventional in vitro studies by incubating FLP with rat and human liver microsomes (RLM, HLM). Known phase I metabolites of FLP (benzamide, benzoic acid, 7-hydroxyl, 8-hydroxyl, 7,8-dihydroxyl FLP, lactam FLP, pyridyl acetic acid, and Z/E-olefin FLP) were successfully simulated by EC/LC/MS. New metabolites including an imide, hydroxyl lactam, and 7-hydroxyl pyridyl acetic acid oxidative metabolites were predicted for the first time in our study using EC/LC/MS and liver microsomes. We found oxidation by dechlorination to be one of the major metabolism mechanisms of FLP. Thus, our results revealed that EC/LC/MS-based metabolic elucidation was more advantageous on time and cost of analysis and enabled matrix-free detection with valuable information about the mechanisms and intermediates of metabolism processes.
Zearalenone (ZEN) and its phase II sulfate and glucoside metabolites have been detected in food and feed commodities. After consumption, the conjugates can be hydrolyzed by the human intestinal microbiota leading to liberation of ZEN that implies an underestimation of the true ZEN exposure. To include ZEN conjugates in routine analysis, reliable standards are needed, which are currently not available. Thus, the aim of the present study was to develop a facilitated biosynthesis of ZEN-14-sulfate, ZEN-14-glucoside and ZEN-16-glucoside. A metabolite screening was conducted by adding ZEN to liquid fungi cultures of known ZEN conjugating Aspergillus and Rhizopus strains. Cultivation conditions and ZEN incubation time were varied. All media samples were analyzed for metabolite formation by HPLC-MS/MS. In addition, a consecutive biosynthesis was developed by using Fusarium graminearum for ZEN biosynthesis with subsequent conjugation of the toxin by utilizing Aspergillus and Rhizopus species. ZEN-14-sulfate (yield: 49%) is exclusively formed by Aspergillus oryzae. ZEN-14-glucoside (yield: 67%) and ZEN-16-glucoside (yield: 39%) are formed by Rhizopus oryzae and Rhizopus oligosporus, respectively. Purities of ≥73% ZEN-14-sulfate, ≥82% ZEN-14-glucoside and ≥50% ZEN-16-glucoside were obtained by 1H-NMR. In total, under optimized cultivation conditions, fungi can be easily utilized for a targeted and regioselective synthesis of ZEN conjugates.
A magnetically stabilized DC arc device, designed for operation with OES spectrometers was used to determine the elements Ag, Al, B, Ba, Be, Ca, Co, Cr, Cu, Fe, Ga, In, K, Li, Mg, Mn, Mo, Na, Nb, Ni, Si, Sn, Sr, Ti, V, Zr at trace levels of some μg kg−1 up to some 10 mg kg−1 in graphite powders. The coil for the generation of the homogeneous magnetic field was placed outside the closed arc chamber. The time programs of variable current strengths of the magnetic coil (up to 6 A) and of the arc (up to 17 A) which was burning in air were computer controlled. Halogenating gases (mainly CCl2F2, alternatively SF6 and NF3) were used as chemical modifiers to allow an effective release of the carbide forming trace elements. The mass flow controlled modifier gas was led through a special carrier electrode near the arc plasma. The emission radiation was guided by an optical fiber alternatively into two different ICP spectrometers in which the ICP torches were removed. The synergistic interaction of the magnetic field with the halogenating modifier gases resulted in a significant improvement in the analytical performance of the optimized analytical method. All our results for 22 trace elements were in good agreement with the means of an inter-laboratory comparison by BAM for certification of a pure graphite powder material; this holds also for our results for two other graphite materials. The optimized method showed an analytical performance suitable for comprehensive trace analysis of pure graphite. The instrumentation could be integrated into modern DC arc emission spectrometers to improve their analytical capabilities substantially.
Proline has been widely used for various cocrystallization applications, including pharmaceutical cocrystals. Combining enantiopure and racemic flurbiprofen and proline, we discovered 18 new crystal structures. Liquid-assisted grinding proved highly efficient to explore all the variety of crystal forms. A unique combination of stateof-the-art characterization techniques, comprising variable temperature in situ X-ray diffraction and in situ ball-milling, along with other physicochemical methods and density functional theory calculations, was indispensable for identifying all the phases. Analyzing the results of in situ ball-milling, we established a stepwise mechanism for the formation of several 1:1 cocrystals via an intermediate 2:1 phase. The nature of the solvent in liquidassisted grinding was found to significantly affect the reaction rate and, in some cases, the reaction pathway.
For the first time, an international comparison was conducted on the determination of the purity of a high purity element. Participants were free to choose any analytical approach appropriate for their institute’s applications and services. The material tested was a high purity zinc, which had earlier been assessed for homogeneity and previously used in CCQM-K72 for the determination of six defined metallic impurities. Either a direct metal assay of the Zn mass fraction was undertaken by EDTA titrimetry, or an indirect approach was used wherein all impurities, or at least the major ones, were determined and their sum subtracted from ideal purity of 100 %, or 1 kg/kg. Impurity assessment techniques included glow discharge mass spectrometry, inductively coupled plasma mass spectrometry and carrier gas hot extraction/combustion analysis. Up to 91 elemental impurities covering metals, non-metals and semi-metals/metalloids were quantified. Due to the lack of internal experience or experimental capabilities, some participants contracted external laboratories for specific analytical tasks, mainly for the analysis of non-metals. The reported purity, expressed as zinc mass fraction in the high purity zinc material, showed excellent agreement for all participants, with a relative standard deviation of 0.011 %. The calculated reference value, w(Zn) = 0.999 873 kg/kg, was assigned an asymmetric combined uncertainty of + 0.000025 kg/kg and – 0.000028 kg/kg. Comparability amongst participating metrology institutes is thus demonstrated for the purity determination of high purity metals which have no particular difficulties with their decomposition / dissolution process when solution-based analytical methods are used, or which do not have specific difficulties when direct analysis approaches are used. Nevertheless, further development is required in terms of uncertainty assessment, quantification of non-metals and the determination of purity of less pure elements and/or for those elements suffering difficulties with the decomposition process.
A frequently studied environmental contaminant is the active substance diclofenac, which is removed insufficiently in sewage treatment plants. Since its inclusion in the watch list of the EU Water Framework Directive, the concentrations in surface waters will be determined throughout Europe. For this, still, more precise analytical methods are needed. As a reference, HPLC-MS is frequently employed. One of the major metabolites is 4’-hydroxydiclofenac (4’-OH-DCF). Also, diclofenac lactam is important for assessing degradation and transformation. Aceclofenac (ACF), the glycolic acid ester of diclofenac is used as a drug, too, and could potentially be cleaved to yield diclofenac again. In various sewage treatment plant influent samples, diclofenac, 4’-OH-DCF, DCF lactam and ACF could be determined with detection limits of 3 µg/L, 0.2 µg/L, 0.17 µg/L and 10 ng/L, respectively.
Single-cell analysis by ICP-MS/MS as a fast tool for cellular bioavailability studies of arsenite
(2018)
Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) has become a powerful and fast tool to evaluate the elemental composition at a single-cell level. In this study, the cellular bioavailability of arsenite (incubation of 25 and 50 μM for 0-48 h) has been successfully assessed by SC-ICP-MS/MS for the first time directly after re-suspending the cells in water. This procedure avoids the normally arising cell membrane permeabilization caused by cell fixation methods (e.g. methanol fixation). The reliability and feasibility of this SC-ICP-MS/MS approach with a limit of detection of 0.35 fg per cell was validated by conventional bulk ICP-MS/MS analysis after cell digestion and parallel measurement of sulfur and phosphorus.
Development and market introduction of new nanomaterials trigger the need for an adequate risk assessment of such products alongside suitable risk communication measures. Current application of classical and new nanomaterials is analyzed in context of regulatory requirements and standardization for chemicals, food and consumer products. The challenges of nanomaterial characterization as the main bottleneck of risk assessment and regulation are presented. In some areas, e.g., quantification of nanomaterials within complex matrices, the establishment and adaptation of analytical techniques such as laser ablation inductively coupled plasma mass spectrometry and others are potentially suited to meet the requirements. As an example, we here provide an approach for the reliable characterization of human exposure to nanomaterials resulting from food packaging. Furthermore, results of nanomaterial toxicity and ecotoxicity testing are discussed, with concluding key criteria such as solubility and fiber rigidity as important parameters to be considered in material development and regulation. Although an analysis of the public opinion has revealed a distinguished rating depending on the particular field of application, a rather positive perception of nanotechnology could be ascertained for the German public in general. An improvement of material characterization in both toxicological testing as well as end-product control was concluded as being the main obstacle to ensure not only safe use of materials, but also wide acceptance of this and any novel technology in the general public.
The recently reported luminescent chromium(III) complex 13+ ([Cr(ddpd)2]3+; ddpd=N,N’-dimethyl-N,N’-dipyridine-2-yl-pyridine-2,6-diamine) shows exceptionally strong near-IR emission at 775 nm in water under ambient conditions (F=11%) with a microsecond lifetime as the ligand design in 13+ effectively eliminates non-radiative decay pathways, such as photosubstitution, back-intersystem crossing, and trigonal twists. In the absence of energy acceptors, such as dioxygen, the remaining decay pathways are energy transfer to high energy solvent and ligand oscillators, namely OH and CH stretching vibrations. Selective deuteration of the solvents and the ddpd ligands probes the efficiency of these oscillators in the excited state deactivation. Addressing these energytransfer pathways in the first and second coordination sphere furnishes a record 30% quantum yield and a 2.3 millisecond lifetime for a metal complex with an earth-abundant metal ion in solution at room temperature.