Spectroscopic Analysis
Mostrando 1-12 de 390 artigos, teses e dissertações.
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1. Spectroscopic techniques combined with chemometrics to study organic matter in tropical soils with different degrees of pedogenetic evolution
Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and
Química Nova. Publicado em: 2022
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2. Royleanine A, an Antitumor Dihydro-β-agarofuran Sesquiterpene Pyridine Alkaloid from Maytenus royleanus
Genus Maytenus (Celastraceae) has proved to be a good source of new bioactive sesquiterpene pyridine alkaloids. Maytenus royleanus is a medicinal plant used in folk medicine for different ailments in a variety of ways around the world. Investigation of the roots of M. royleanus resulted in the isolation of an undescribed antitumor sesquiterpene pyridine alka
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Reduced Graphene Oxide/Ruthenium Oxide Hexacyanoferrate Nanocomposite for Electrochemical Determination of Ethanol in Commercial Samples
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
J. Braz. Chem. Soc.. Publicado em: 2021-06
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4. Individuals with untreated psychiatric disorders and suicide in the COVID-19 era
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
Braz. J. Psychiatry. Publicado em: 2021-06
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5. Increased depression and anxiety during the COVID-19 pandemic in Brazilian mothers: a longitudinal study
Reduced graphene oxide/ruthenium oxide hexacyanoferrate (rGO/RuOHCF) modified electrode showed synergic activity between the materials attested by the increase of electrochemical current and stability. The preparation of the nanocomposite was made by a simple two-step electrochemical approach. The material structure was characterized by spectroscopic techniq
Braz. J. Psychiatry. Publicado em: 2021-06
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6. Structural Study of Wheat Gliadin in Different Solvents by Spectroscopic Techniques
Physicochemical properties of gliadin in different solvents (dimethyl sulfoxide (DMSO), H2O, and aqueous ethanol) and pH (9.8, 6.8, and 1.2) were investigated using dynamic light scattering (DLS), zeta potential (ZP), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Gliadin-DMSO and gliadin-deionized water (H2O) (pH 9.8) s
J. Braz. Chem. Soc.. Publicado em: 2021-04
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7. Sunlight-Driven Dehydrogenative Oxidation Photocatalysis by a Mononuclear Complex Acting as both Chromophore and Catalyst
Under simulated solar irradiation in the visible spectral region, the catalytically active RuIV-oxo species [Ru(O)(bpy)(tppz)]2+ (tppz = tetrapyridylpyrazine, a strongly π-accepting tridentate N, N, N-ligand) is produced directly from a single metal-to-ligand charge-transfer (MLCT) photoexcitation of the resting RuII-aquo complex [Ru(H2O)(bpy)(tppz)]2+ in a
J. Braz. Chem. Soc.. Publicado em: 2020-11
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8. Synthesis, Characterization, Absorption and Fastness Properties of Novel Monoazo Dyes Derived from 1-Phenyl-3-amino-4-(2-thiazolilazo)pyrazol-5-one
Monosubstitute thiazolyl amines were diazotized in acetic acid, coupled to 1-phenyl-3-aminopyrazol-5-one (1a-1c) and acetylated to obtain the 2a-2c dyes. The dyes were characterized by elemental analysis and spectroscopic (Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), ultraviolet (UV)) methods. The effects on the visible absorption spe
J. Braz. Chem. Soc.. Publicado em: 2020-09
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9. Evaluation of quality parameters and chromatographic, spectroscopic, and thermogravimetric profile of Patauá oil (Oenocarpus bataua)
Abstract The objective of this research was to evaluate the quality parameters and the chromatographic, thermogravimetric, and spectroscopic profile of Patauá oil (Oenocarpus bataua). All analyses were performed according to the Recommended Practices of the American Oil Chemists’ Society (AOCS). The parameters obtained indicate conservation quality standa
Food Sci. Technol. Publicado em: 2020-06
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10. A NEW SECO-LIMONOID FROM THE INFLORESCENCES OF Dictyoloma vandellianum
Phytochemical investigation of the inflorescences of Dictyoloma vandellianum A. Juss. (Rutaceae) has led to the isolation of a new A-seco-limonoid, named dictyolomol (1), along with a known quinolone alkaloid, casimiroine (2), previously isolated from the same species. The structures were established by spectroscopic analysis such as one- and two-dimensional
Quím. Nova. Publicado em: 2020-05
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11. Theoretical and Experimental Investigations on Inclusion Complex β-Cyclodextrin and Sulcatone: A Cardiovascular Activity Evaluation
In this paper, we have applied state-of-the-art technologies and new investigations were developed focusing on obtaining simple and inexpensive molecules for treating cardiovascular diseases, as they are considered the leading cause of death in the world. For the first time, the inclusion complex of sulcatone (SU) and β-cyclodextrin (β-CD) was achieved (us
J. Braz. Chem. Soc.. Publicado em: 2020-05
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12. ANÁLISE ESPECTROSCÓPICA DA MATÉRIA ORGÂNICA NO SEDIMENTO SUPERFICIAL DA BAÍA DE SEPETIBA, RIO DE JANEIRO, BRASIL
Spectroscopic techniques are powerful tools for molecular organic matter assessment in sediments, which analysis request low sample mass and are cheap, fast and easy to obtain. The aim of this work was to evaluate the elemental (C, N) and molecular composition of the organic matter in relation to the grain-size distribution over surface sediments from Sepeti
Quím. Nova. Publicado em: 2020-05