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| Registros recuperados: 15 | |
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| MATOS, W. O.; PUYOL, M.; IBÁÑEZ- GARCÍA, N.; NOGUEIRA, A. R. de A.; CHAMARRO, J. A.. |
| Selênio é reconhecido como um micronutriente essencial. Porém, a bioutilidade deste elemento está intrísecamente dependente da sua forma química. Espécies orgânicas de selênio são mais facilmente absorvidas por organismos humanos quando comparado a suas espécies inorgânicas. Castanhas do Brasil podem ser consideradas uma boa fonte de selênio, pois apresenta concentrações significativas deste elemento, principalmente na forma de selenometionina.1 Neste trabalho, sistema para análise em fluxo para a determinação de selenometionina em amostras de castanha do Brasil empregando quimioluminescência foi desenvolvido, utilizando uma célula de reação com estrutura em vórtex construída com tecnologia LTCC2. |
| Tipo: Resumo em anais de congresso (ALICE) |
Palavras-chave: Selenometionima; Castanha do brasil; Quimioninescência. |
| Ano: 2007 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/48119 |
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| MATOS, W. O.; NÓBREGA, J. de A.; SOUZA, G. B. de; NOGUEIRA, A. R. de A.. |
| Determination of Cr(VI) and Cr(III) was studied in soil samples accidentally contaminated with sulphochromic solution. Molecular absorption spectrophotometry based on the diphenylcarbazide method was used for the determination of Cr(VI) after its alkaline extraction. The total chromium concentration was determined using ICP OES. The quantification of Cr(III) was accomplished by subtracting the Cr(VI) concentration from the total chromium concentration. Regardless of the known contamination of the soil samples by sulphochromic solution, concentrations of Cr(VI) were below the detection limit. Addition and recovery experiments for Cr(VI) in soil samples with and without organic matter indicated its influence on the reduction of Cr(VI) to Cr(III). |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Chromium: Redox; Speciation; Solo. |
| Ano: 2008 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/48502 |
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| GROMBONI, C. F.; DONATI, G. L; MATOS, W. O.; NEVES, E. F. A.; NOGUEIRA, A. R. de A.; NOBREGA, J. A.. |
| Efficiency of metabisulfite and a commercial steel wool as reducing agents in the removal of Cr(VI) from wastewaters was evaluated. Chromium( VI) was converted to Cr(III), precipitated with NaOH, and removed by filtration. A reduction of more than 1.0 x 10(5) and 4.0 x 10(5) fold in total Cr and the Cr(VI) concentrations, respectively, was observed by employing steel wool masses as low as 0.4420 g to 30-mL solutions of wastewater. Chromium(III) hydroxide obtained after the treatment was recycled and used as marker in cattle nutrition studies. The liquid residue obtained after the treatment was reused as precipitation agent replacing NaOH. |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Wastewater treatment; Metabisulfite; Steel wood. |
| Ano: 2010 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/863457 |
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| Registros recuperados: 15 | |
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