Cyclic Oxidation
Mostrando 25-36 de 156 artigos, teses e dissertações.
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25. Preparation of a Nitrite Electrochemical Sensor Based on Polyaniline/ Graphene‑Ferrocenecarboxylic Acid Composite Film Modified Glass Carbon Electrode and its Analytical Application
A sensitive and stable electrochemical sensor based on polyaniline/graphene-ferrocenecarboxylic acid (PANI/GR-FCA) composite film modified glass carbon electrode for determination of nitrite was presented and its morphology and structure were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrar
J. Braz. Chem. Soc.. Publicado em: 2015-10
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26. New and Sensitive Electroquantification of Sulfentrazone in Soil by Differential-Pulse Voltammetry
In this work, a new and sensitive electroanalytical methodology was developed and validated to quantify sulfentrazone in soil samples. Sulfentrazone was initially characterized qualitatively using cyclic voltammetry (CV). Its oxidation occurred by diffusion (mass transport) on a glassy carbon electrode (GCE) via irreversible transfer of one electron close to
J. Braz. Chem. Soc.. Publicado em: 2015-09
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27. CuO Nanofibers Immobilized on Paraffin-Impregnated Graphite Electrode and its Application in the Amperometric Detection of Glucose
1-D nanostructures are promising materials for development of electrochemical devices offering benefits such as fast electron transfer rates and large surface areas. Copper oxide nanofibers (CuO-NFs) synthesized by electrospinning technique and subsequent thermal treatment, were used to modify paraffin-impregnated graphite electrode (PIGE) for a sensitive
J. Braz. Chem. Soc.. Publicado em: 2015-08
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28. Simultaneous Determination of Ascorbic Acid, L-Dopa, Uric Acid, Insulin, and Acetylsalicylic Acid on Reactive Blue 19 and Multi-Wall Carbon Nanotube Modified Glassy Carbon Electrode
A trifunctional electrochemical sensor was fabricated for simultaneous determination of ascorbic acid (AA), levodopa (LD), and insulin. This was done by modifying a glassy carbon electrode (GCE) with multi-walled carbon nanotubes and reactive blue 19 (RB-MWCNT-GCE). Cyclic voltammetry was used to investigate the redox properties of this modified electrode. T
J. Braz. Chem. Soc.. Publicado em: 2015-04
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29. Selective Determination of Unsymmetrical Dimethylhydrazine on a Prussian Blue Modified Carbon Paste Electrode
The electrocatalytic oxidation of unsymmetrical dimethylhydrazine (UDMH) has been studied on a Prussian Blue modified carbon paste electrode (PBMCPE) by cyclic voltammetry technique. The results show that Prussian Blue acts as a suitable modifier for electron transfer in the oxidation of UDMH. A linear range of 3 × 10-5 to 1.15 × 10-3 mol L-1, with a limit
J. Braz. Chem. Soc.. Publicado em: 2015-03
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30. A simple square-wave voltammetric method for the determination of scopolamine in pharmaceuticals using a boron-doped diamond electrode
A simple procedure is described for the determination of scopolamine by square-wave voltammetry using a cathodically pretreated boron-doped diamond electrode. Cyclic voltammetry studies indicate that the oxidation of scopolamine is irreversible at a peak potential of 1.59 V (vs. Ag/AgCl (3.0 mol L-1 KCl)) in a 0.50 mol L-1 sulfuric acid solution. Under optim
Quím. Nova. Publicado em: 2014
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31. DETERMINAÇÃO DE ÁCIDO LIPÓICO SOBRE ELETRODO DE GRAFITE PIROLÍTICO MODIFICADO COM FTALOCIANINA DE COBALTO / DETERMINATION OF LIPOIC ACID ON PYROLYTIC GRAPHITE ELECTRODE MODIFIED WITH COBALT PHTHALOCYANINE
Lipoic acid, also known as thioctic acid is a compound organosulfur derived from octanoic acid, which is a saturated fatty acid. It is an antioxidant that has the property of suppressing free radicals in both aqueous and lipid environment, which differs from other antioxidants. Nowadays, various techniques are employed for determining the lipoic acid such as
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/07/2012
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32. Mecanismos moleculares da ação tóxica pró-oxidante de 1,4-diamino-2-butanona, um análogo de putrescina, sobre células de mamíferos e Trypanosoma cruzi / The Molecular mechanisms of pro-oxidant activity of 1,4-diamino-2-butanone, a putrescine analogue, to mammalian cells and Trypanosoma cruzi
α-Aminocarbonyl componds such as 5-aminolevunilic acid (ALA) and aminoacetone (AA) have been shown to exhibit pro-oxidant properties. These compounds undergo phosphate-catalyzed enolization in physiological pH and subsequent aerobic oxidation, yielding reactive oxygen species, NH4+ ions and an α-oxoaldehyde highly cytotoxic. The α-aminoketone 1
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/06/2012
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33. ESTUDO DA REAÇÃO DE REDUÇÃO DE OXIGÊNIO SOBRE ELETRODOS À BASE DE TETRAMETÓXIFENILPORFIRINAS PARA APLICAÇÕES EM CÉLULAS A COMBUSTÍVEL DE BOROIDRETO DIRETO / STUDY OF THE OXYGEN REDUCTION REACTION ON ELECTRODES BASED OF TETRAMETÓXIFENILPORFIRINAS FOR APPLICATIONS IN CELLS FUEL BOROHYDRIDE DIRECT
The oxygen reduction reaction (ORR) in 1.0 mol/L KOH solutions catalyzed by FeTMPP/C and CoTMPP/C was investigated in absence and presence of BH4- anions with concentrations varying from 10-7 to 1.0 mol/L. Similar cyclic voltammetry and rotating disk electrode experiments have been also performed the commercial E-TEK Pt/C electrocatalysts. In absence of BH4-
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/06/2012
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34. Determinação voltamétrica de ricina em mamona usando carbono vítreo e diamante dopado com boro / Voltammetric determination of ricin in castor bean using gassy carbon and boron doped diamond.
Ricin (RCA 60) is an inhibitor of ribosomes protein toxic, of class II, extracted from castor bean endosperm of the seed, consisting of two peptide chains (RCA-A 30 and RCA-B 30) linked by a disulfide bridge covalently formed by the combination of 17 amino acid residues. Its toxicity has been observed in animals, insects and humans, being by inhalation, inge
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/03/2012
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35. Platinum and nioubium based catalysts for the anode of polymer electrolyte membrane fuel cells fed with low molecular weight alcohols / Catalisadores a base de platina e nióbio para o ânodo da célula a combustível de membrana trocadora de prótons alimentada com alcoóis de baixa massa molecular
In this work, the methanol and ethanol electrochemical oxidation reactions are studied on platinum (Pt) and niobium (Nb) catalysts supported on high surface area carbon. The selected materials were PtNb/C, Pt-Nb2O5(amorphous) /C e Pt-Nb2O5(crystalline) /C, using as reference for comparison purposes the commercial catalyst 20% Pt-C E-TEK. The catalysts were p
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/01/2012
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36. Optical (DRUV-VIS) and magnetic (EPR) behavior of synthetic melanins
The properties of melanins prepared from L-dopa oxidation by both chemical and electrochemical methods are reported, searching for a material with more intense optical absorption in the visible region. The characterization of the samples have been done by cyclic voltammetry (CV), cronoamperometry (CA), Fourier transformed infrared spectroscopy (FTIR), electr
Materials Research. Publicado em: 06/03/2012