Chemische Charakterisierung und Spurenanalytik
Filtern
Dokumenttyp
- Zeitschriftenartikel (71) (entfernen)
Schlagworte
- Mass-Spectrometry (8)
- Mycotoxins (8)
- Cancer (7)
- Food (5)
- Transformation products (5)
- Electrochemistry (4)
- HRMS (4)
- Mass Spectrometry (4)
- Mass spectrometry (4)
- Metabolomics (4)
- Metrology (4)
- Tumor metabolism (4)
- Fatty acid metabolism (3)
- Food analysis (3)
- Lipidomic profile (3)
- Mass Spectroscopy (3)
- Metabolic stress (3)
- Mycotoxin (3)
- Quality assurance (3)
- Adsorption (2)
- Analytical Chemistry (2)
- Certified reference material (2)
- Ergot alkaloids (2)
- Fluorescence (2)
- Gas chromatography (2)
- HPLC-MS/MS (2)
- Hydrazinolysis (2)
- Interlaboratory comparison (2)
- MYCN (2)
- Purity assessment (2)
- R package (2)
- Reference material (2)
- Reproducibility (2)
- Transformation product (2)
- Volatile organic compounds (2)
- 2,5-dihydroxyacetophenone (1)
- ABID (1)
- Acrylamide (1)
- Aflatoxins (1)
- Altenuene (1)
- Alternaria mycotoxins (1)
- Aluminum (1)
- Analyseverfahren (1)
- Analytical methods (1)
- Antagonists (1)
- Antibody identification (1)
- App (1)
- Aspergillus (1)
- BERM (1)
- Benz[a]anthracene (BaA) (1)
- Benzo[a]pyrene (BaP) (1)
- Bioconjugation (1)
- Biosynthesis (1)
- Biotests (1)
- Biotransformation (1)
- Bisphenol-A (1)
- Breath (1)
- CCQM (1)
- CCQM key comparison (1)
- CE/MC-ICP-MS (1)
- COVID-19 (1)
- Cadmium (1)
- Cancer awareness measure (1)
- Cancer cells (1)
- Cancer risk (1)
- Cancer therapy (1)
- Canine olfactometry (1)
- Chemical Safety (1)
- Cleavage (1)
- Cocoa (1)
- Combustion Ion Chromatography (1)
- Complexation (1)
- Conjugate (1)
- Consumer Products (1)
- Corona virus (1)
- DHAP (1)
- Data processing (1)
- Debromination (1)
- Derivatization (1)
- Dimerization (1)
- Dried fig (1)
- EC/LC/MS (1)
- EC/MS (1)
- ECR (1)
- Electrochemical Reactor (1)
- Electrochemical oxidation (1)
- Electrochemistry mass spectrometry (1)
- Emerging brominated flame retardant (1)
- Emerging contaminants (1)
- Emerging/novel brominated flame retardant (1)
- Esterification (1)
- Ethyl glucuronide (1)
- European Reference Material (1)
- Extraction (1)
- Fatty acid desaturation (1)
- Fatty acid synthesis (1)
- Fatty acid uptake (1)
- Fatty acids (1)
- Fenton’s reagent (1)
- Fertilizer (1)
- Fluorophilic interactions (1)
- Fluxomics (1)
- Folic acid (1)
- Food Analysis (1)
- Food contaminants (1)
- Food fermentation (1)
- Food safety (1)
- Fungicide (1)
- Fusarium (1)
- Fusarium mycotoxin (1)
- Gas analysis (1)
- Gas chromatography (GC) (1)
- Github (1)
- HLA (1)
- HPLC-DAD/FLD (1)
- Hydrazin (1)
- Hydrolysis (1)
- Hydroxylation (1)
- ICP-ToF-MS (1)
- ISO REMCO (1)
- Identity (1)
- Indoor air (1)
- Interlaboratory key comparison (1)
- Ionophore (1)
- Ionophore antibiotics (1)
- Isotope (1)
- Isotope Labelling (1)
- Isotope dilution (ID) (1)
- Isotope ratio (1)
- Isotope-labeled (1)
- Isotopologue Distribution (1)
- Job plot (1)
- LC-MS/MS (1)
- LC/HRMS (1)
- Lasalocid (1)
- Laser Ablation/Imaging (1)
- Library (1)
- Light chain (1)
- Lipid metabolism (1)
- Lipidomics (1)
- Liquid chromatography (1)
- Liquid chromatography (LC) (1)
- Lung cancer (1)
- Lysergic acid hydrazide (1)
- MALDI (1)
- MC-ICP-MS (1)
- MOSH/MOAH (1)
- Mass spectrometry (MS) (1)
- Mass-spectrometry (1)
- Massenspektrometrie (1)
- Metabolic Flux (1)
- Metabolism (1)
- Metabolization (1)
- Method development (1)
- Microbe interactions (1)
- Mineral oil hydrocarobons (1)
- Mobile analysis (1)
- Mobile analytics (1)
- Modified mycotoxins (1)
- Monensin (1)
- Monoclonal antibody (1)
- Moxidectin (1)
- Mycotoxin Analysis (1)
- NIST-mAb 8671 (1)
- NMR (1)
- Nanomaterials (1)
- Network (1)
- Non-target (1)
- Non-targeted analysis (1)
- Nucleocapsid (1)
- On-site detection (1)
- Open science (1)
- Organic Synthesis (1)
- Organic contaminants (1)
- Oxidative metabolism (1)
- PAH (1)
- PAHs (1)
- PFAS (1)
- Peptide mass fingerprinting (1)
- Peptides (1)
- Per- and Polyfluoroalkyl substances (PFAS) (1)
- Pesticide (1)
- Photochemistry (1)
- Photodegradation (1)
- Polycyclic aromatic hydrocarbon (PAH) (1)
- Polycyclic aromatic hydrocarbons (1)
- Polyurethanes (1)
- Priority effect (1)
- Proficiency testing (1)
- Pulverization (1)
- Pyrolysis (1)
- Quality Assurance (1)
- Quality control (1)
- Quantitative determination (1)
- RBD (1)
- Rat/human liver microsomes (1)
- Recombinant antibody (1)
- Reference Material (1)
- Reference materials (1)
- Remediation (1)
- Renal disease (1)
- Reversible covalent hydrazine chemistry (RCHC) (1)
- Rhizopus (1)
- Rhizopus and Aspergillus oryzae (1)
- SDHI-fungicide (1)
- SIDA-LC-MS/MS (1)
- SOM-SM (1)
- Safety (1)
- Salinomycin (1)
- Screening method (1)
- Sensors (1)
- Sequence coverage (1)
- Sequencing (1)
- Sewage sludge (1)
- Society of hair testing (1)
- Software (1)
- Speiseöle (1)
- Spike protein (1)
- Stakeholders (1)
- Standardization (1)
- Standards (1)
- Sum Parameter (1)
- Sum Parameter Method (1)
- Sum parameter method (1)
- Sustainable Food Safety (1)
- Suzuki coupling (1)
- TGA-FTIR (1)
- Thermal decomposition (1)
- Thermal degradation (1)
- Thermo-desorption (1)
- Toxicity testing (1)
- Toys (1)
- Traceability (1)
- Transformationsprodukte (1)
- Transient signal (1)
- Truffle (1)
- Truffle Aroma (1)
- Tryptic digest (1)
- Tuber melanosporum (1)
- UV irradiation (1)
- Urine (1)
- VOC (1)
- Validation trial (1)
- Vegetable edible oil (1)
- Veterinary drugs (1)
- Volatile marker (1)
- Volatile organic compounds; (1)
- Yerba mate tea (1)
- Zearalenone (1)
- Zearalenone sulfate (1)
- Zenodo (1)
- a-zearalenol (1)
- species-specific isotope information (1)
Organisationseinheit der BAM
- 1.7 Organische Spuren- und Lebensmittelanalytik (71) (entfernen)
Lipid droplets, the dynamic organelles that store Triglycerides (TG) and cholesterol esters (CE), are highly accumulated in colon cancer cells. This work studies the TG and CE subspecies profile in colon carcinoma cell lines, SW480 derived from primary tumor, and SW620 derived from a metastasis of the same tumor. It was previously reported that the total TG and CE content is dramatically higher in SW620 cells; however, TG and CE subspecies profile has not been investigated in detail. The work presented here confirms that the total TG and CE Content is significantly higher in the SW620 cells. Moreover, the fatty acid (FA) composition of TG is significantly altered in the SW620 cells, with significant decrease in the abundance of saturated triglycerides. This resulted in a significantly decreased TG saturation index in the SW620 cells. The saturation index of CE was also significantly decreased in the SW620 cells.
Zearalenone (ZEN), an estrogenic mycotoxin produced by several species of Fusarium fungi, is a common contaminant of cereal-based food worldwide. Due to frequent occurrences associated with high levels of ZEN, maize oil is a particular source of exposure. Although a European maximumlevel for ZEN in maize oil exists according to Commission Regulation (EC) No. 1126/2007 along with a newly developed international standard method for analysis, certified reference materials (CRM) are still not available. To overcome this lack, the first CRM for the determination of ZEN in contaminated maize germ oil (ERM®-BC715) was developed in the frame of a European Reference Materials (ERM®) project according to the requirements of ISO Guide 35. The whole process of CRM development including preparation, homogeneity and stability studies, and value assignment is presented. The assignment of the certified mass fraction was based upon an in-house study using high-performance liquid chromatography isotope dilution tandem mass spectrometry. Simultaneously, to support the in-house certification study, an interlaboratory comparison study was conducted with 13 expert laboratories using different analytical methods. The certified mass fraction and expanded uncertainty (k=2) of ERM®-BC715 (362± 22) μg kg−1 ZEN are traceable to the SI. This reference material is intended for analytical quality control and contributes to the improvement of consumer protection and food safety.
Molekülmassenspektrometrie entwickelt sich weg von klassischer Target- hin zu Nontarget-Analytik. Elementmassenspektrometrie liefert hohe Ortsauflösung beim Element-Imaging und analysiert einzelne Zellen. Aufgrund der Fortschritte bei den Geräten für Timeof-Flight-Massenspektrometrie mit induktiv gekoppeltem Plasma (ICPToF-MS) lässt sich das gesamte Periodensystem der Elemente in kurzen transienten Signalen quasi-simultan massenspektrometrisch erfassen.
Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40-60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed.
The demonstration of competency and equivalence for the assessment of levels of contaminants and nutrients in primary foodstuffs is a priority within the 10-year strategy for the OAWG Track A core comparisons. The measurements are core challenges for reference material producers and providers of calibration Services. This key comparison related to low polarity analytes in a high fat, low protein, low carbohydrate food matrix and Benzo[a]pyrene in edible oil was the model System selected to align with this class within the OAWG strategy. Evidence of successful participation in formal, relevant international comparisons is needed to document measurement capability claims (CMCs) made by national metrology institutes (NMIs) and designated institutes (Dis). 16 National Metrology Institutions participated in the Track A Key Comparison CCQM-K146 Low-Polarity Analyte in high fat food: Benzo[a]pyrene in Olive Oil. Participants were requested to evaluate the mass fractions, expressed in µg/kg, of Benzo[a]pyrene in the olive oil material. The KCRV was determined from the results of all NMIs/DIs participating in the key comparison that used appropriately validated methods with demonstrated metrological traceability. Different methods such as liquid-liquid extraction, GPC and SPE were applied in the sample pretreatment and HPLC-FLD, HPLC-MS/MS, and GC-MS or GC-MS/MS were applied for detection by the participants. The mass fractions for BaP were in the range of (1.78 to 3.09) µg/kg with Standard uncertainties of (0.026 to 0.54) µg/kg, with corresponding relative Standard uncertainties from 0.9% to 21%. Five labs withdrew their result from the Statistical evaluation of the KCRV for technical reasons. One lab was excluded from the KCRV evaluation, as they did not meet the CIPM metrological traceability requirements. A Hierarchical Bayes option was selected for the KCRV value, which was determined as 2.74 µg/kg with a Standard uncertainty of 0.03 µg/kg. The 10 institutes those were included in the calculation of the consensus KCRV all agreed within their Standard uncertainties. Successful participation in CCQM-K146 demonstrates the measurement capabilities in determining mass fraction of organic compounds, with molecular mass of 100 g/mol to 500 g/mol, having low polarity pKow < -2, in mass fraction range from 0.1 µg/kg to 1000 µg/kg in a high fat, low protein, low carbohydrate food matrix.
Mycotoxigenic fungal pathogens Fusarium and Alternaria are a leading cause of loss in cereal production. On wheat-ears, they are confronted by bacterial antagonists such as pseudomonads.
Studies on these groups’ interactions often neglect the infection process’s temporal aspects and the associated priority effects. In the present study, the focus was on how the first colonizer affects the subsequent ones. In a climate chamber experiment, wheat-ears were successively inoculated with two different strains (Alternaria enuissima At625, Fusarium graminearum Fg23, or Pseudomonas simiae Ps9).
Over three weeks, microbial abundances and mycotoxin concentrations were analyzed and visualized via Self Organizing Maps with Sammon Mapping (SOM-SM). All three strains revealed different characteristics and strategies to deal with co-inoculation: Fg23, as the first colonizer, suppressed the establishment of At625 and Ps9. Nevertheless, primary inoculation of At625 reduced all of the Fusarium toxins and stopped Ps9 from establishing. Ps9 showed priority effects in delaying and blocking the production of the fungal mycotoxins. The SOM-SM analysis visualized the competitive strengths: Fg23 ranked first, At625 second, Ps9 third. Our findings of species-specific priority effects in a natural environment and the role of the mycotoxins involved are relevant for developing biocontrol strategies.
In recent years numerous reports have highlighted the options of chemical breath analysis with regard to noninvasive cancer detection. Certain volatile organic compounds (VOC) supposedly present in higher amounts or in characteristic patterns have been suggested as potential biomarkers. However, so far no clinical application based on a specific set of compounds appears to exist. Numerous reports on the capability of sniffer dogs and sensor arrays or electronic noses to distinguish breath of cancer patients and healthy controls supports the concept of genuine cancer-related volatile profiles. However, the actual compounds responsible for the scent are completely unknown and there is no correlation with the potential biomarkers suggested on basis of chemical trace analysis.
It is outlined that specific features connected with the VOC analysis in breath – namely small concentrations of volatiles, interfering background concentrations, considerable sampling effort and sample instability, impracticability regarding routine application - stand in the way of substantial progress. The underlying chemicalanalytical challenge can only be met considering the severe susceptibility of VOC determination to these adverse conditions.
Therefore, the attention is drawn to the needs for appropriate quality assurance/quality control as the most important feature for the reliable quantification of volatiles present in trace concentration. Consequently, the advantages of urine as an alternative matrix for volatile biomarker search in the context of diagnosing lung and other cancers are outlined with specific focus on quality assurance and practicability in clinical chemistry. The headspace over urine samples as the VOC source allows adapting gas chromatographical procedures well-established in water analysis. Foremost, the selection of urine over breath as non-invasive matrix should provide considerably more resilience to adverse effects during sampling and analysis. The most important advantage of urine over breath is seen in the option to partition, dispense, mix, spike, store, and thus to dispatch taylor-made urine samples on demand for quality control measures. Although it is still open at this point if cancer diagnosis supported by non-invasively sampled VOC profiles will ultimately reach clinical application the advantages of urine over breath should significantly facilitate urgently required steps beyond the current proof-of-concept stage and towards standardisation.
Since 1 January 2019 a maximum content of 0.6 mg kg−1 cadmium (Cd) in cocoa powder sold to the final consumer or as an ingredient in sweetened cocoa powder sold to the final consumer (drinking chocolate) is set by the Commission Regulation (EU) No. 488/2014. Monitoring compliance with the specified limit value requires analytical measuring methods and reference materials for quality control. However, suitable certified reference materials intended for quality assurance and quality control purposes are still lacking. Therefore, three cocoa reference materials (ERM®-BD513, ERM®-514 and ERM®-515) were developed according to the requirements of ISO 17034 and the recommendations of ISO Guide 35. The whole process of reference material development, including material preparation, assessment of homogeneity and stability, characterisation and value assignment is presented. The assignment of the certified mass fractions was based upon an interlaboratory comparison study involving 19 expert laboratories for Cd and 12 laboratories for acrylamide. The certified mass fractions and expanded uncertainties (k = 2) of the reference materials were (0.181 ± 0.009) mg kg−1 Cd (ERM®-BD513), (0.541 ± 0.024) mg kg−1 Cd (ERM®-BD514) and (0.690 ± 0.029) mg kg−1 Cd (ERM®-BD515). Acrylamide contents are given for information.
Moxidectin (MOX) is a widely used anthelmintic drug for the treatment of internal and external parasites in food-producing and companion animals. Transformation products (TPs) of MOX, formed through metabolic degradation or acid hydrolysis, May pose a potential environmental risk, but only few were identified so far. In this study, we therefore systematically characterized electro- and photochemically generatedMOX TPs using high-resolution mass spectrometry (HRMS). Oxidative electrochemical (EC) TPs were generated in an electrochemical reactor and photochemical (PC) TPs by irradiation with UV-C light. Subsequent HRMS measurements were performed to identify accuratemasses and deduce occurring modification reactions of derived TPs in a suspected target analysis. In total, 26 EC TPs and 59 PC TPs were found. The main modification reactions were hydroxylation, (de-)hydration, and derivative formation with methanol for EC experiments and isomeric changes, (de-)hydration, and changes at the methoxime moiety for PC experiments. In addition, several combinations of different modification reactions were identified.
For 17 TPs, we could predict chemical structures through interpretation of acquired MS/MS data. Most modifications could be linked to two specific regions of MOX. Some previously described metabolic reactions like hydroxylation or O-demethylation were confirmed in our EC and PC experiments as reaction type, but the corresponding TPs were not identical to known metabolites or degradation products. The obtained knowledge regarding novel TPs and reactions will aid to elucidate the degradation pathway of MOX which is currently unknown.
Multiple works have studied possible associations between human leukocyte antigen (HLA) alleles and end stage renal disease (ESRD). However, there are several contradictions in these previous works and no consistent HLA associations with ESRD itself have been identified. Most of these works have several limitations, for instance, the population size was too small, or only limited HLA loci were studied. The presented work aims to revisit the association between ESRD and HLA antigens while taking in to account the previously overlooked limitations. Here, we compared the HLA polymorphism (at HLA-A, -B, -C, -DRB1, -DQB1 and DQA1 loci) in ESRD patients (n=497) and controls (n=672). Our data identified several HLA alleles that displayed a significant positive or negative association with ESRD. We also determined whether heterozygosity or homozygosity of the ESRD-associated HLA alleles at different loci could modify the prevalence of the disease. Few HLA allele combinations displayed significant associations with ESRD among which HLA-A*3 –HLA-A*26 combination showed the highest strength of association (OR= 4.488, P≤ 0.05) with ESRD. However, the age of ESRD onset was not affected by HLA allele combinations at different loci. Most of the previous works have studied the association of HLA with ESRD in homogeneous ethnic groups and have interpreted their data accordingly. Here, we also performed an extensive literature analysis to determine whether the association of HLA to ESRD can be similar across different ethnic groups. This analysis showed that at least for certain alleles, the association of HLA to ESRD can be similar in different ethnic groups. For instance, HLA-A*11, HLA-DRB1*11, and HLA-DRB1*4 all showed significant positive associations with ESRD in different ethnic groups. The findings of our study will help in determining possible protective or susceptible roles of various HLA alleles in ESRD.