Especiação redox de crômio em amostras de solos contaminados
Chromium and its compounds are employed in various industrial processes, and these activities are responsible for the disposal of significant amounts of materials containing this element in the environment. Due to the known toxic feature of Cr(VI) in biological systems, the determination of chromium...
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Universidade Federal de São Carlos
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ftunivfsaocarlos:oai:repositorio.ufscar.br:ufscar/6522 2023-05-15T13:39:06+02:00 Especiação redox de crômio em amostras de solos contaminados Redox especiation of chromium in contaminated soil samples Canevari, Natália Tostes Pereira Filho, Edenir Rodrigues PEREIRA FILHO, E. R http://lattes.cnpq.br/7309684456090159 2012-03-21 application/pdf https://repositorio.ufscar.br/handle/ufscar/6522 por por Universidade Federal de São Carlos BR UFSCar Programa de Pós-Graduação em Química - PPGQ CANEVARI, Natália Tostes. Redox especiation of chromium in contaminated soil samples. 2012. 87 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/6522 Acesso Aberto Química analítica Especiação química redox Solos Espectrofotometria Análise por injeção de fluxo Espectroscopia de absorção de raios X CIENCIAS EXATAS E DA TERRA::QUIMICA Dissertação 2012 ftunivfsaocarlos 2022-03-05T18:35:00Z Chromium and its compounds are employed in various industrial processes, and these activities are responsible for the disposal of significant amounts of materials containing this element in the environment. Due to the known toxic feature of Cr(VI) in biological systems, the determination of chromium species has acquired great importance in environmental chemistry. In this study three analytical strategies were combined, X-ray absorption spectroscopy, flame atomic absorption spectrometry and UV-Vis molecular absorption spectrophotometry, in order to identify and determine Cr(III) and (VI) in contaminated soil samples. The samples were collected around the Comandante Ferraz Antarctic Station, a Brazilian scientific station in Antarctica. For the pseudototal chromium analysis, acid digestion was employed for sample preparation and determinations were performed using a flame atomic absorption spectrometer. Na2CO3 0.28 mol L-1 - NaOH 0.5 mol L-1 extractor solution and heating were used for Cr(VI) extraction in the samples, and preliminary identification of this specie was performed using XANES and EXAFS techniques at the Brazilian Synchrotron Light Laboratory. For Cr(VI) determination, NaOH 0.1 mol L-1 and heating were employed for the extraction of the specie, and determinations were based on the reaction of Cr(VI) with the colorimetric reagent diphenylcarbazide in acid medium, using a flow injection analysis system coupled to a molecular absorption spectrophotometer. The quantification of Cr(III) was carried out by subtraction between the pseudototal chromium concentration and Cr(VI) concentration. Results obtained were compared with those calculated from the determination of Cr(VI) with diphenylcarbazide in batch mode. Chromium (VI) concentrations determined in soil samples using both methods were discordant, and these differences were originated from problems occurred in the developed flow injection analysis system. Financiadora de Estudos e Projetos O crômio e seus compostos são empregados em diversos ... Thesis Antarc* Antarctic Antarctica Repositório Institucional Universidade Federal de São Carlos (RI UFSCar) Antarctic Ferraz ENVELOPE(-64.117,-64.117,-65.117,-65.117) Solos’ ENVELOPE(42.706,42.706,64.750,64.750) |
institution |
Open Polar |
collection |
Repositório Institucional Universidade Federal de São Carlos (RI UFSCar) |
op_collection_id |
ftunivfsaocarlos |
language |
Portuguese |
topic |
Química analítica Especiação química redox Solos Espectrofotometria Análise por injeção de fluxo Espectroscopia de absorção de raios X CIENCIAS EXATAS E DA TERRA::QUIMICA |
spellingShingle |
Química analítica Especiação química redox Solos Espectrofotometria Análise por injeção de fluxo Espectroscopia de absorção de raios X CIENCIAS EXATAS E DA TERRA::QUIMICA Canevari, Natália Tostes Especiação redox de crômio em amostras de solos contaminados |
topic_facet |
Química analítica Especiação química redox Solos Espectrofotometria Análise por injeção de fluxo Espectroscopia de absorção de raios X CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
Chromium and its compounds are employed in various industrial processes, and these activities are responsible for the disposal of significant amounts of materials containing this element in the environment. Due to the known toxic feature of Cr(VI) in biological systems, the determination of chromium species has acquired great importance in environmental chemistry. In this study three analytical strategies were combined, X-ray absorption spectroscopy, flame atomic absorption spectrometry and UV-Vis molecular absorption spectrophotometry, in order to identify and determine Cr(III) and (VI) in contaminated soil samples. The samples were collected around the Comandante Ferraz Antarctic Station, a Brazilian scientific station in Antarctica. For the pseudototal chromium analysis, acid digestion was employed for sample preparation and determinations were performed using a flame atomic absorption spectrometer. Na2CO3 0.28 mol L-1 - NaOH 0.5 mol L-1 extractor solution and heating were used for Cr(VI) extraction in the samples, and preliminary identification of this specie was performed using XANES and EXAFS techniques at the Brazilian Synchrotron Light Laboratory. For Cr(VI) determination, NaOH 0.1 mol L-1 and heating were employed for the extraction of the specie, and determinations were based on the reaction of Cr(VI) with the colorimetric reagent diphenylcarbazide in acid medium, using a flow injection analysis system coupled to a molecular absorption spectrophotometer. The quantification of Cr(III) was carried out by subtraction between the pseudototal chromium concentration and Cr(VI) concentration. Results obtained were compared with those calculated from the determination of Cr(VI) with diphenylcarbazide in batch mode. Chromium (VI) concentrations determined in soil samples using both methods were discordant, and these differences were originated from problems occurred in the developed flow injection analysis system. Financiadora de Estudos e Projetos O crômio e seus compostos são empregados em diversos ... |
author2 |
Pereira Filho, Edenir Rodrigues PEREIRA FILHO, E. R http://lattes.cnpq.br/7309684456090159 |
format |
Thesis |
author |
Canevari, Natália Tostes |
author_facet |
Canevari, Natália Tostes |
author_sort |
Canevari, Natália Tostes |
title |
Especiação redox de crômio em amostras de solos contaminados |
title_short |
Especiação redox de crômio em amostras de solos contaminados |
title_full |
Especiação redox de crômio em amostras de solos contaminados |
title_fullStr |
Especiação redox de crômio em amostras de solos contaminados |
title_full_unstemmed |
Especiação redox de crômio em amostras de solos contaminados |
title_sort |
especiação redox de crômio em amostras de solos contaminados |
publisher |
Universidade Federal de São Carlos |
publishDate |
2012 |
url |
https://repositorio.ufscar.br/handle/ufscar/6522 |
long_lat |
ENVELOPE(-64.117,-64.117,-65.117,-65.117) ENVELOPE(42.706,42.706,64.750,64.750) |
geographic |
Antarctic Ferraz Solos’ |
geographic_facet |
Antarctic Ferraz Solos’ |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_relation |
CANEVARI, Natália Tostes. Redox especiation of chromium in contaminated soil samples. 2012. 87 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2012. https://repositorio.ufscar.br/handle/ufscar/6522 |
op_rights |
Acesso Aberto |
_version_ |
1766114523324874752 |