Hydroquinone
Mostrando 1-12 de 151 artigos, teses e dissertações.
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1. Additive Manufacturing towards the Fabrication of Greener Electrochemical Sensors for Antioxidants
Additive manufacturing is an emerging tool that has contributed to the sustainable fabrication of devices in several areas based on the concept of “zero waste”. Considering extrusion-based manufacturing (or 3D printing), polylactic acid (PLA) has been highlighted due to its biodegradability, obtention from renewable sources, and compatibility for 3D prin
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Synthesis of Antioxidant Additive from Safflower Seed Oil
Several published studies have evaluated the problems associated with the utilization of biodiesel obtained from safflower (Carthamus tinctorius L.) oil due to the low oxidative stability, caused by the high content of unsaturated fatty acids. Thus, this study aimed at the extraction of safflower seed oil and its use as an unsaturation source to obtain a syn
J. Braz. Chem. Soc.. Publicado em: 2021-01
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3. EVALUATION OF THE PHOTOCATALYTIC ACTIVITY OF SiO2@TiO2 HYBRID SPHERES IN THE DEGRADATION OF METHYLENE BLUE AND HYDROXYLATION OF BENZENE: KINETIC AND MECHANISTIC STUDY
Abstract Silica spheres coated with titania (SiO2@TiO2) were synthesized using chitosan as template. The N2 adsorption/desorption isotherms of the spheres point to meso and macroporous characteristics and the elemental mapping by EDS shows uniform distribution of Ti on the surface of the silica spheres, leading to formation of an amorphous structure (XRD). T
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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4. Determination of Catechol and Hydroquinone by Using Perilla frutescens Activated Carbon Modified Glassy Carbon Electrode
High specific surface area activated carbon prepared by Perilla frutescens (PFHSAAC) was modified on the surface of the glassy carbon electrode (GCE) by drop-coating method to construct a PFHSAAC/GCE. The electrochemical properties of the modified electrode were investigated in detail by some electrochemical methods such as cyclic voltammetry (CV), different
J. Braz. Chem. Soc.. Publicado em: 2020-01
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5. N-Acetyl-cysteine Increases Chemical Stability of Hydroquinone in Pharmaceutical Formulations: a Theoretical and Experimental Approach
In this study, the chemistry stability of hydroquinone (HQ) was evaluated according to its effects in redox properties and compared to kojic acid (KA). The HQ oxidation was more inhibited by N-acetylcysteine (NAC) than ascorbic acid (AA). These results were elucidated using theoretical methods at the DFT/B3LYP level of theory. All electronic parameters were
J. Braz. Chem. Soc.. Publicado em: 2018-03
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6. Simultaneous Determination of Different Phenolic Compounds Using Electrochemical Biosensor and Multivariate Calibration
Phenolic compounds are important environmental contaminants due to their high toxicity and persistence in the environment. The use of enzyme-based electrochemical biosensors is a simple, sensitive and low-cost alternative for the determination of these pollutants in contaminated waters. However, in most cases, it is impossible to detect specific compounds in
J. Braz. Chem. Soc.. Publicado em: 2018-03
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7. Chemical constituents from Casearia spp. (Flacourtiaceae/Salicaceae sensu lato)
ABSTRACT Chemical investigation of the leaves of Casearia gossypiosperma Briq., Salicaceae, led to the isolation of two known flavonoids, (+)-taxifolin and quercetin, the leaves of Casearia decandra Jacq. have afforded hydroquinone, the leaves of Casearia rupestris Eichler and Casearia lasiophylla Eichler have afforded a diterpene, (E)-phytol, and the leaves
Rev. bras. farmacogn.. Publicado em: 2017-12
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8. An overview of dermatological and cosmeceutical benefits of Diospyros kaki and its phytoconstituents
Abstract Diospyros kaki L.f. belonging to family Ebenaceae, commonly known as persimmon is used as a medicinal plant in Chinese traditional medicine since many years for different ailments including cosmetics and dermatologic applications. Traditionally this plant is used to treat different skin conditions including pimples, skin eruptions and eczema. Presen
Rev. bras. farmacogn.. Publicado em: 2017-10
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9. Influence of the Protonatable Site in the Photo-Induced Proton-Coupled Electron Transfer between Rhenium(I) Polypyridyl Complexes and Hydroquinone
In the present work the influence of the distance of the protonatable site of different ancillary ligands to the metal center on the luminescence quenching of ReI polypyridyl complexes by hydroquinone are evaluated by means of experimental and theoretical studies. In these systems, it is expected the occurrence of proton-coupled electron transfer (PCET) reac
J. Braz. Chem. Soc.. Publicado em: 2017-09
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10. Determination of Chlorophenol in Environmental Samples Using a Voltammetric Biosensor Based on Hybrid Nanocomposite
In this work, a simple electrochemical biosensor for 4-chlorophenol was developed based on laccase immobilized on a hybrid nanocomposite (ZnO nanoparticles/chitosan), and incorporated in a carbon paste electrode. There are few biosensors in the literature for this specific pollutant because it tends to form polymeric films on the electrode, causing surface p
J. Braz. Chem. Soc.. Publicado em: 2017-07
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11. PROCEDIMENTO AUTOMÁTICO PARA DETERMINAÇÃO ESPECTROFOTOMÉTRICA DE HIDROQUINONA EMPREGANDO MULTICOMUTAÇÃO EM SISTEMA DE ANÁLISE EM FLUXO
This paper describes a procedure based on multicommutation in flow analysis system for photometric determination of hydroquinone in pharmaceutical gel formulations. The procedure involves oxidation of hydroquinone by Fe (III) and subsequent reaction between the generated Fe (II) species with 1,10-phenanthroline, producing a complex detected at 510 nm. Under
Quím. Nova. Publicado em: 2016-06
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12. Contribution of Irradiation and Dihydroxybenzenes on Iron(III) Reduction in Fenton Process
The contribution of irradiation and the dihydroxybenzenes (DHB), catechol (CAT) and hydroquinone (HQ), added or formed as phenol oxidation intermediates, was evaluated for the reduction of FeIII and for phenol degradation via Fenton processes. The formation of CAT and HQ was observed during phenol degradation starting with Fe2+ or Fe3+ in the presence or abs
J. Braz. Chem. Soc.. Publicado em: 2016-06