Chemische Charakterisierung und Spurenanalytik
Filtern
Erscheinungsjahr
- 2019 (208) (entfernen)
Dokumenttyp
- Vortrag (98)
- Zeitschriftenartikel (67)
- Posterpräsentation (36)
- Beitrag zu einem Tagungsband (2)
- Dissertation (2)
- Buchkapitel (1)
- Sonstiges (1)
- Forschungsbericht (1)
Sprache
- Englisch (161)
- Deutsch (45)
- Mehrsprachig (2)
Schlagworte
- ICP-MS (13)
- Mikroplastik (13)
- Process Analytical Technology (12)
- Isotope analysis (9)
- LIBS (9)
- Laser ablation (9)
- Online NMR Spectroscopy (9)
- CONSENS (8)
- Digitalisierung (8)
- HR-CS-MAS (8)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (158)
- 1.1 Anorganische Spurenanalytik (46)
- 6 Materialchemie (40)
- 1.4 Prozessanalytik (38)
- 1.6 Anorganische Referenzmaterialien (28)
- 1.7 Organische Spuren- und Lebensmittelanalytik (28)
- 1.8 Umweltanalytik (28)
- 6.6 Physik und chemische Analytik der Polymere (21)
- 6.3 Strukturanalytik (18)
- 1.9 Chemische und optische Sensorik (13)
- 4 Material und Umwelt (13)
- P Präsident (13)
- P.0 Präsident und andere (12)
- 4.5 Kunst- und Kulturgutanalyse (6)
- 4.2 Material-Mikrobiom Wechselwirkungen (4)
- S Qualitätsinfrastruktur (4)
- 1.5 Proteinanalytik (3)
- 4.1 Biologische Materialschädigung und Referenzorganismen (3)
- S.1 Qualität im Prüfwesen (3)
- 1.3 Instrumentelle Analytik (2)
- 4.3 Schadstofftransfer und Umwelttechnologien (2)
- 7 Bauwerkssicherheit (2)
- 8 Zerstörungsfreie Prüfung (2)
- PST Präsidiale Stabsstelle (2)
- 1.0 Abteilungsleitung und andere (1)
- 1.2 Biophotonik (1)
- 4.0 Abteilungsleitung und andere (1)
- 5 Werkstofftechnik (1)
- 5.6 Glas (1)
- 6.1 Oberflächen- und Dünnschichtanalyse (1)
- 7.0 Abteilungsleitung und andere (1)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (1)
- 8.0 Abteilungsleitung und andere (1)
- 8.5 Röntgenbildgebung (1)
- 9 Komponentensicherheit (1)
- 9.0 Abteilungsleitung und andere (1)
- 9.4 Integrität von Schweißverbindungen (1)
- S.2 Digitalisierung der Qualitätsinfrastruktur (1)
Eingeladener Vortrag
- nein (98)
Environmental sustainability and –stability of materials concerning the migration of pollutants
(2019)
In addition to previously reported results on the accelerated weathering of polystyrene samples (PS) containing 1 wt. % hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene samples (PP) containing 0.1 wt. % BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006. For the determination of BDE-209 in the collected raining water the samples were prepared in accordance to a validated protocol. Before the analyses each sample was spiked with isotopically labeled BDE-209. Subsequently the samples were extracted with isooctane. The obtained extracts were concentrated, and the resulting solutions were analyzed by GC/MS. Additionally, the total bromine content was monitored for the weathered and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF) as a non-destructive and rapid method. In general, the resulting data from the accelerated weathering will be compared to those from the natural weathering experiments. Here, the surfaces of the test pieces were analyzed by LA-ICP-MS and XRF as well. Moreover, soil bed tests were conducted in a well characterized model soil. This soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining basin inside of an air-conditioned cellar. In this manner, TOC, water capacity and humidity are recorded parameters. To induce a leaching process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. A defined humidity is a fundamental parameter for a biological activity in the soil. The test polymers were placed up to the half in the soil. Microbial activity of the soil is monitored by a reference polymer (polyurethane) and should induce the release of HBCD and BDE-209 out of the test materials. These released analytes will be captured by passive samplers (silicone tubes) placed in a distinct distance to the polymer samples in the soil. The soil bed experiments are complementary to the weathering experiments due to the biological activity in the soil.
In addition to previously reported results on the accelerated weathering of polystyrene samples (PS) containing 1 wt.% hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene samples (PP) containing 0.1 wt.% BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006. For the determination of BDE-209 in the collected raining water the samples were prepared in accordance to a validated protocol. Before the analyses each sample was spiked with isotopically labeled BDE-209. Subsequently the samples were extracted with isooctane. The obtained extracts were concentrated, and the resulting solutions were analyzed by GC/MS. Additionally, the total bromine content was monitored for the weathered and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF) as a non-destructive and rapid method. In general, the resulting data from the accelerated weathering will be compared to those from the natural weathering experiments. Here, the surfaces of the test pieces were analyzed by LA-ICP-MS and XRF as well. Moreover, soil bed tests were conducted in a well characterized model soil. This soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining basin inside of an air-conditioned cellar. In this manner, TOC, water capacity and humidity are recorded parameters. To induce a leaching process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. A defined humidity is a fundamental parameter for a biological activity in the soil. The test polymers were placed up to the half in the soil. Microbial activity of the soil is monitored by a reference polymer (polyurethane) and should induce the release of HBCD and BDE-209 out of the test materials. These released analytes will be captured by passive samplers (silicone tubes) placed in a distinct distance to the polymer samples in the soil. The soil bed experiments are complementary to the weathering experiments due to the biological activity in the soil.
Zu den letzten beiden Jahrestagungen der GUS wurden Verfahren und Methoden vorgestellt, die es gestatten, den Transfer von Schadstoffen aus Materialien und Produkten in die Umwelt unter umweltrelevanten Bedingungen beschreiben zu können. Dabei lag der Fokus auf den Materialien und der eingesetzten Umweltsimulationen. In einem sich anschließenden Schritt soll nun das Verhalten der freigesetzten organischen Schadstoffe unter den Bedingungen von realen und simulierten Umwelteinflüssen charakterisiert und beschrieben werden. Hier werden im Detail drei potentielle Schadstoffe betrachtet, die Inhaltsstoffe bzw. Additive in den jeweils eingesetzten Materialien sind. Im Falle von Polypropylen (PP) und Polystyrol (PS) handelt es sich um polybromierte Flammschutzmittel BDE 209 (Decabrom-diphenylether, als Einzelsubstanz) und HBCD (Hexabromcyclododecan, als technische Formulierung). Für das eingesetzte Polycarbonat ist BPA (Bisphenol A) als Schadstoff zu definieren, welcher unter umweltrelevanten Bedingungen freigesetzt wird. Im Rahmen der durchzuführenden Arbeiten sollen die aufgeführten prioritären Schadstoffe hinsichtlich möglicher Transformationsprozesse in Umwelt und Klärwerk charakterisiert werden. Die unter den Bedingungen der Ozonung, Chlorierung und UV-Bestrahlung erhaltenen Transformationsprodukte (TPs) sollen im Sinne einer Non-Target-Analytik identifiziert und eindeutig charakterisiert werden. Die Ergebnisse sollen mittels vorhandener Analysenverfahren, wie GC-EI-MS, HPLC-ESI-IT-MSn bzw. LC-MS/MS erzeugt bzw. abgesichert werden. Anhand der in der Struktur eindeutig zu beschreibenden Transformationsprodukte und der Charakterisierung von potentiellen Intermediaten sollen belastbare Reaktionswege und –mechanismen abgeleitet werden.
Cancer cell lipid class homeostasis is altered under nutrient-deprivation but stable under hypoxia
(2019)
Background: Cancer cells modify the balance between fatty acid (FA) synthesis and uptake under metabolic stress, induced by oxygen/nutrient deprivation. These modifications were shown to alter the levels of individual triglyceride (TG) or phospholipid sub-species. To attain a holistic overview of the lipidomic profiles of cancer cells under stress we performed a broad lipidomic assay, comprising 244 lipids from six major classes. This assay allowed us to perform robust analyses and assess the changes in averages of broader lipid-classes, stratified on the basis of saturation index of their fatty-acyl side chains.
Methods: Global lipidomic profiling using Liquid Chromatography-Mass Spectrometry was performed to assess lipidomic profiles of biologically diverse cancer cell lines cultivated under metabolically stressed conditions.
Results: Neutral lipid compositions were markedly modified under serum-deprived conditions and, strikingly, the cellular level of triglyceride subspecies decreased with increasing number of double bonds in their fatty acyl chains.
In contrast and unexpectedly, no robust changes were observed in lipidomic profiles of hypoxic (2% O2) cancer cells despite concurrent changes in proliferation rates and metabolic gene expression.
Conclusions: Serum-deprivation significantly affects lipidomic profiles of cancer cells. Although, the levels of individual lipid moieties alter under hypoxia (2% O2), the robust averages of broader lipid classes remain unchanged.
Regardless of its ban in agricultural use, the triazine derivative terbutryn is still used as a biocide against biofouling in building materials, such as façade colors and roof tiles. From there, it is washed off and may contaminate soil and surface waters, where it shows ecotoxicological behavior. For understanding of these leaching processes, analytical methods that can detect terbutryn in traces are necessary. In contrast to separation methods (Gas (GC) or liquid chromatography (LC)) coupled to mass spectrometry (MS), enzyme immunoassays (EIAs) have proven to be adequate tools for environmental monitoring. Compared to GC-or LC-MS, they are cheap, require only limited time and experimental expertise and enable high throughput. For quantification of terbutryn, EIAs have been established, with a limit of detection (LOD) of 50 ng L-1. For leaching experiments however, a lower LOD would be advantageous.
For detection of terbutryn we developed a direct competitive ELISA based on a monoclonal antibody: Terbutryn and an enzyme-terbutryn conjugate (“tracer”) compete for the binding sites of the immobilized antibody. The bound tracer converts a colourless substrate into a blue-coloured product, which can be detected via spectrophotometry. For quantification of terbutryn, a sigmoidal calibration curve is used. For establishing of the EIA, a new tracer based on a terbutryn surrogate (“hapten”) was synthesized. After optimization of the experimental conditions, the immunoassay exhibited a more than ten-fold increased sensitivity (LOD: 3 ng L-1), high stability against sample compounds (Ca2+, NaCl) and lower cross-reactivities against structurally related compounds, than reported before. Analysis of spiked samples was possible with high precision (inter-assay CV: < 10 %) and accuracy (recoveries from spiked samples: 89 % ± 10%). We therefore propose it as quick and reliable method for leaching studies of terbutryn out of building materials.
The development of an automated miniaturized analytical system that allows for the rapid monitoring of carbamazepine (CBZ) levels in serum and wastewater is proposed. Molecular recognition of CBZ was achieved through its selective interaction with microbeads carrying anti-CBZ antibodies. The proposed method combines the advantages of the micro-bead injection spectroscopy and of the flow-based platform lab-on-valve for implementation of automatic immunosorbent renewal, rendering a new recognition surface for each sample. The sequential (or simultaneous) perfusion of CBZ and the horseradish peroxidase-labelled CBZ through the microbeads is followed by real-time on-column Monitoring of substrate (3,30,5,50-tetramethylbenzidine) oxidation by colorimetry. The evaluation of the initial oxidation rate and also the absorbance value at a fixed time point provided a linear response versus the logarithm of the CBZ concentration. Under the selected assay conditions, a single analysis was completed after only 11 min, with a quantification range between 1.0 and 50 µg L⁻¹. Detection of CBZ levels in undiluted wastewater samples was feasible after a simple filtration step while good recoveries were attained for spiked certified human serum, analyzed without sample clean-up.
We present the optical sensing of phthalate Esters (PAEs), a group of endocrine-disrupting chemicals. The sensing takes place as changes in the fluorescence emission intensity of aminopyrene covalently bound to the organic ligands of the metal−organic framework compound ZIF-8. In the presence of PAEs, a quenching of the fluorescence emission is observed. We evaluated strategies to engineer colloidal size distribution of the sensing particles to optimize the sensory response to PAEs. A thorough characterization of the modified ZIF-8 nanoparticles included powder X-ray diffractometry, transmission electron microscopy, high-performance liquid chromatography, and photophysical characterization. The presented capability of the fluorophore-functionalized ZIF-8 to sense PAEs complements established methods such as chromatography-based procedures, which cannot be used on-site and paves the way for future developments such as hand-held quick sensing devices.
Today, in scientific events often a certain separation between researchers from laboratories with highly sophisticated equipment and those from less privileged laboratories can be observed. It is not an uncommon situation that results presented at conferences are rubbished or ridiculed because the investigator only used low-end analytical methods.
The assessment of the study is then biased based on the equipment, regardless of the actual quality of the study.