Copper Speciation
Mostrando 1-12 de 15 artigos, teses e dissertações.
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1. Elemental Concentration and Sulfur Chemical Speciation in the Amazonian Plant Andira surinamensis Using Synchrotron Radiation Techniques (SR-XRF, XANES), RBS and WD-XRF
The inorganic composition of the bark and leaf of a plant from the Amazon rainforest, Andira surinamensis, was determined using two non-destructive, multi-element techniques: X-ray fluorescence (XRF) and Rutherford backscattering spectrometry (RBS). XRF measurements were made using both a conventional X-ray source and synchrotron radiation. It was observed t
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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2. Tilapia (Oreochromis niloticus) as a Biondicator of Copper and Cadmium Toxicity. A Bioavailability Approach
The acute toxicity of copper and cadmium in Oreochromis niloticus was evaluated through a 96 h static assay. Precipitation of Cu and co-precipitation of Cd in the presence of Cu were noted, being indicative of differences in nominal and actual concentrations of metals. Under these conditions, LC50-96h was determined as 3.53 mg L-1Cu, 20.1 mg L-1 Cd and 1.36
J. Braz. Chem. Soc.. Publicado em: 2017-01
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3. Análise de especiação de cobre e zinco empregando voltametria de redissolução anódica com pulso diferencial
This work describes methodologies for speciation analysis of the metals copper and zinc as total, total dissolved, labile, as well as complexation capacity (conditional stability constants and available ligand concentration), using the same technique, differential pulse anodic stripping voltammetry (DPASV). Several supporting electrolytes were tested, and th
Química Nova. Publicado em: 2012
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4. Especiação de cobre e zinco em urina: importância dos metais em doenças neurodegenerativas
Metals such as copper and zinc are essential for the development and maintenance of numerous enzymatic activities, mitochondrial functions, neurotransmission, and also for memorization and learning. However, disruption in their homeostasis can cause neurodegenerative disorders such as the Alzheimer and Parkinson diseases. In this work, the speciation of copp
Quím. Nova. Publicado em: 2012
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5. The effects of solar irradiation on copper speciation and organic complexation
Este trabalho teve como objetivo avaliar o efeito da irradiação solar na especiação do cobre em amostras de água coletadas em um reservatório eutrofizado e contaminado por metais. Voltametria de redissolução anódica e eletrodo de íon seletivo foram utilizados para determinação de cobre nas amostras irradiadas e não irradiadas. Os resultados demo
Journal of the Brazilian Chemical Society. Publicado em: 2011-09
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6. Fatores que governam a especiação do cobre em ambientes aquáticos urbanos: evidências da contribuição de sulfetos solúveis
Copper speciation and behavior in different rivers located in the city of Curitiba were evaluated in this work. Sampling locations were selected to cover different levels of urbanization regarding their anthropogenic occupation and land use. Results showed that in highly-developed areas, both organic matter and dissolved sulfides were able to control copper
Química Nova. Publicado em: 2007-04
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7. Behavior of B, Zn, Cu, Mn e Pb in contaminated soil under plant cultivation and organic matter addition for metal toxicity amelioration / Comportamento de B, Zn, Cu, Mn e Pb em solo contaminado sob cultivo de plantas e adição de fontes de matéria orgânica como amenizantes do efeito tóxico
Two pot trials were carried out using a heavy metal accidentally contaminated soil. In the first one it was evaluated the plant absorbing, translocating and accumulating power for zinc, copper, manganese, lead and boron by the following vegetal species: Brassica juncea, Raphunus sativus L., Hybiscus cannabinus and Amaranthus crentus, so they could help in th
Publicado em: 2005
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8. Digestão fotoquímica, assistida por microondas, de águas naturais: aplicação em estudos de partição e especiação do cobre
The efficiency of a new procedure for the digestion of natural waters, based on a microwave-activated photochemical reactor was evaluated in this work. Fluorescence spectra showed a 99% reduction in the emission of a 40 mg L-1 humic acid solution after 15 min of UV irradiation. In the presence of H2O2, only 3 min were necessary to accomplish a reduction of a
Química Nova. Publicado em: 2004-10
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9. Sequential extraction and ionic speciation of zinc, copper and cadmium in oxisols amended with biosolid. / Extração seqüencial e especiação iônica de zinco, cobre e cádmio em latossolos tratados com biossólido.
Com o crescimento urbano e industrial houve considerável aumento na geração de resíduos, tais como os biossólidos provenientes de estações de tratamento de esgoto. Diversas estratégias de utilização desse resíduo tem sido propostas, e o uso agrícola como fertilizante tem se tornado prática comum. Entretanto, os biossólidos podem apresentar car�
Publicado em: 2003
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10. Métodos de baixo custo para purificação de reagentes e controle da contaminação para a determinação de metais traços em águas naturais
Probably one of the most difficult and challenging aspects of measuring trace metals in natural waters is to avoid contamination during sampling, manipulation and analysis. This work discusses how to avoid contamination using simple procedures, and considers alternative methods to purify deionised water and low grade reagents to enable accurate determination
Química Nova. Publicado em: 2002-09
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11. Construção e otimização de um reator de baixo custo para a fotodegradação da matéria orgânica em águas naturais e sua aplicação no estudo da especiação do cobre por voltametria
This work describes the construction of a home-made low-cost reactor, using easily available materials, capable of destroying efficiently dissolved organic matter. Just 30 minutes of irradiation were sufficient to destroy more than 99% of the humic acids present in a solution of 4 mg C L-1. Copper speciation was evaluated in natural waters of different salin
Química Nova. Publicado em: 2001-04
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12. Effect of Copper Speciation on Whole-Cell Soluble Methane Monooxygenase Activity in Methylosinus trichosporium OB3b
Soluble methane monooxygenase (sMMO) activity in Methylosinus trichosporium OB3b was found to be more strongly affected as copper-to-biomass ratios changed in a newly developed medium, M2M, which uses pyrophosphate for metal chelation, than in nitrate mineral salts (NMS), which uses EDTA. When M2M medium was amended with EDTA, sMMO activity was similar to th
American Society for Microbiology.