Chromatography Coupled To Mass Spectrometry
Mostrando 1-12 de 292 artigos, teses e dissertações.
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1. Study of Catalytic Pyrolysis of Biomass Sorghum (Sorghum bicolor L. Moench) Using Design of Experiments and Surface Response Methodology
This study proposes a screen of variables that have an influence on the modification of the bio-oil chemical composition as a unique critical quality attribute (CQA) throughout the pyrolytic process (zeolite, ZSM-5) by using a 24 full factorial design, followed by optimization through a response surface methodology (RSM) based on central composite design (CC
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. TANINOS E FLAVONOIDES DAS FLORES DE EUGENIA UNIFLORA (MYRTACEAE)
Eugenia uniflora, popularly known as pitanga, is a native species of the Brazilian flora, widely used in folk medicine for the treatment of various diseases and which has several bioactive chemical constituents. The aim of this work was to analyze the chemical composition of flowers visited by bees from Eugenia uniflora by Ultra-Performance Liquid Chromatogr
Química Nova. Publicado em: 2022
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3. Use of Direct Aqueous Injection and Solid Phase Extraction Coupled with Hydrophilic Interaction Chromatography to Analyze Haloacetic Acids in Drinking Water Samples
In this study, two analytical methods were evaluated to determine haloacetic acids (HAAs) in drinking water samples. Direct aqueous injection (DAI) and solid phase extraction (SPE) were evaluated and determination was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) with a hydrophilic interaction chromatography (HILIC) analytical column
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Phytocomponents, Evaluation of Anticholinesterase Activity and Toxicity of Hydroethanolic Extracts of Parkia platycephala Benth.
This study evaluated the chemical composition, antioxidant and anticholinesterase activities, and the toxicity of hydroethanolic extracts of the Parkia platycephala Benth. Hot extraction with 70% hydroethanolic solution was used to obtain crude extracts of the leaf (LE), bark (BE), flower (FE), and seed (SE). Separation and identification of the compounds we
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Evaluation of sediment contamination by urban sewage in a stretch of Capibaribe River, Pernambuco, Brazil
Anthropic activities are responsible for the increase in environmental contamination, especially in aquatic systems, demanding studies to assess and monitor contamination levels in different water bodies. We have done a chemical characterization of eleven sediments in order to evaluate the level of contamination by domestic sewage from the Capibaribe River,
Química Nova. Publicado em: 2022
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6. Simultaneous GC-NCI-MS Determination of Persistent Organic Pollutants and Current-Use Pesticides in Breast Milk Samples
To preserve human health, persistent organic pollutants (POPs) and current-use pesticides (CUPs) should be monitored in fatty tissues, including breast milk. Therefore, this study aimed to optimize sample preparation conditions using a 32 factorial design for the determination of POPs and CUPs by gas chromatography coupled to mass spectrometry with negative
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. Evaluation of residues of β-lactam, sulfonamide, tetracycline, quinolone, fluoroquinolone e pyrimidine in raw milk
Abstract Food quality and safety have been a concern of the world population, especially in relation to the chemical and microbiological hazards present in food. The presence of antimicrobial residues at levels above the maximum residue limit makes milk unsuitable for human consumption. In this context, the objective of this study was to analyze 184 raw milk
Food Sci. Technol. Publicado em: 2021-09
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8. Polyphenol Profile and Quantitative Assessment of the Flavonoid Kaempferitrin in Wild and Cultivated Brazilian Amazonian Uncaria guianensis (Rubiaceae)
The Amazonian Rubiaceae species Uncaria guianensis (UG) is locally used as anti-inflammatory, antitumor, antidiabetic, anti-ulcers, and others. The phenolic content of its leaves is characterized by the great predominance of the flavonoid kaempferol-3,7-O-(α)-L-dirhamnoside (kaempferitrin). The present study quantitatively evaluates the kaempferitrin conten
J. Braz. Chem. Soc.. Publicado em: 2021-08
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9. Stability Analyses by HPLC-MS of Guanitoxin Isolated from Sphaerospermopsis torques-reginae
Guanitoxin (GNT) is a natural organophosphate produced by some species of freshwater cyanobacteria, which inhibits the active site of acetylcholinesterase, preventing the hydrolysis of cholinesterases and consequently causing serious disturbances in the neuromuscular system. Despite having a chemical structure like synthetic organophosphates, there is still
J. Braz. Chem. Soc.. Publicado em: 2021-08
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10. Integrated UPLC-HRMS, Chemometric Tools, and Metabolomic Analysis of Forage Palm (Opuntia spp. and Nopalea spp.) to Define Biomarkers Associated with Non-Susceptibility to Carmine Cochineal (Dactylopius opuntiae)
Metabolomics, together with analytical methods and chemometric tools, point to new paths for selecting species that are resistant to pests and diseases. In this work, the forage palm species' metabolomic profile was investigated, and the relation between the chemical composition and resistance to Dactylopius opuntiae (carmine cochineal). The study was perfor
J. Braz. Chem. Soc.. Publicado em: 2021-08
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11. Essential Oils Obtained from Aerial Eugenia punicifolia Parts: Chemical Composition and Antiproliferative Potential Evidenced through Cell Cycle Arrest
Essential oils (EOs) of the leaves of three Eugenia punicifolia specimens from two different Reservation Parks, namely Parque Nacional das Nascentes do Rio Parnaíba (EpNRP-I and EpNRP-II) and Parque Nacional da Chapada das Mesas (EpCM), in the state of Maranhão, Brazil, were extracted by hydrodistillation and investigated by gas chromatography coupled to m
J. Braz. Chem. Soc.. Publicado em: 2021-07
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12. Chemical Constituents and Cytotoxic Activity of Rhinella jimi (Anura: Bufonidae)
Rhinella jimi toads (Stevaux, 2002) belong to the Bufonidae family, are endemic in the Brazilian Northeast and are commonly found during rainy periods. In general, amphibians of this family have in their poisons different metabolites that show a diversity of pharmacological activities. The isolation and identification of these compounds are of great importan
J. Braz. Chem. Soc.. Publicado em: 2021-05