Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Manancial - Repositório Digital da UFSM |
Texto Completo: | http://repositorio.ufsm.br/handle/1/4184 |
Resumo: | This work aimed to explore the speciation analysis of chromium, selenium and antimony, elements of clinical and geochemical relevance, in the saline samples seawater, hydrothermal fluid and hemodialysis fluid. These samples, although linked to different research areas, have many similarities relating to their chemical compositions or the presence of metallic species as contaminants as well as major components. Voltammetric methods were used to the determination of the analytes in high salt media without the use of dilution, masking agents or separation steps. Since changes in the matrix composition may affect the analyte peak current magnitude, factors affecting the voltammetric behavior of the species related to sample composition (e.g., presence of dissolved organic matter and ionic strength) were evaluated. The chromium speciation analysis was performed by the adsorptive collection of the Cr-DTPA complex on the mercury working electrode, followed by stripping in combination to a catalytic step. Cr(III) species was found as predominant in the hydrothermal fluid sample and, Cr(VI), in the seawater sample, whereas in hemodialysis fluids an ignorable concentration was determined. Selenium was determined by the co-electrolysis of Cu2Se followed by a cathodic stripping in acidic medium. The UV-irradiation pre-treatment step was used for the reductively conversion of non-electroactive species into Se(IV) as well as for dissolved organic matter photo-oxidation, and the speciation was applied to the real sample analysis, where no selenium species were found. The combined use of adsorptive and anodic stripping voltammetry was employed for antimony determination. Chloranilic acid was chosen as the Sb(III) complex forming reagent (pH 3.0) and the total antimony concentration was evaluated by anodic stripping voltammetry in a 5.0 mol L-1 HCl medium. Sb(III) was found as the predominant species in the hydrothermal fluid sample, whereas Sb(V) is predominant in the seawater sample. No antimony species were found in the hemodialysis fluid. Concerning chromium, selenium and antimony species, remarkable peak current dependences on peak potential, deposition potential, deposition time and scan rate were observed for all investigated media. The limit of detection values were appropriate to the analytes determination, so that the present techniques consist in simple, fast and low cost procedures for the speciation analysis of elements of clinical and geochemical relevance in high salt content samples with accuracy and sensitivity. |
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Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinasApplication of voltammetric methods to the speciation analysis of chromium, selenium and antimony in saline matricesEspeciaçãoCromoSelênioAntimônioMétodos voltamétricosAmostras salinasSpeciation analysisChromiumSeleniumAntimonyVoltammetric methodsSaline samplesCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICAThis work aimed to explore the speciation analysis of chromium, selenium and antimony, elements of clinical and geochemical relevance, in the saline samples seawater, hydrothermal fluid and hemodialysis fluid. These samples, although linked to different research areas, have many similarities relating to their chemical compositions or the presence of metallic species as contaminants as well as major components. Voltammetric methods were used to the determination of the analytes in high salt media without the use of dilution, masking agents or separation steps. Since changes in the matrix composition may affect the analyte peak current magnitude, factors affecting the voltammetric behavior of the species related to sample composition (e.g., presence of dissolved organic matter and ionic strength) were evaluated. The chromium speciation analysis was performed by the adsorptive collection of the Cr-DTPA complex on the mercury working electrode, followed by stripping in combination to a catalytic step. Cr(III) species was found as predominant in the hydrothermal fluid sample and, Cr(VI), in the seawater sample, whereas in hemodialysis fluids an ignorable concentration was determined. Selenium was determined by the co-electrolysis of Cu2Se followed by a cathodic stripping in acidic medium. The UV-irradiation pre-treatment step was used for the reductively conversion of non-electroactive species into Se(IV) as well as for dissolved organic matter photo-oxidation, and the speciation was applied to the real sample analysis, where no selenium species were found. The combined use of adsorptive and anodic stripping voltammetry was employed for antimony determination. Chloranilic acid was chosen as the Sb(III) complex forming reagent (pH 3.0) and the total antimony concentration was evaluated by anodic stripping voltammetry in a 5.0 mol L-1 HCl medium. Sb(III) was found as the predominant species in the hydrothermal fluid sample, whereas Sb(V) is predominant in the seawater sample. No antimony species were found in the hemodialysis fluid. Concerning chromium, selenium and antimony species, remarkable peak current dependences on peak potential, deposition potential, deposition time and scan rate were observed for all investigated media. The limit of detection values were appropriate to the analytes determination, so that the present techniques consist in simple, fast and low cost procedures for the speciation analysis of elements of clinical and geochemical relevance in high salt content samples with accuracy and sensitivity.Conselho Nacional de Desenvolvimento Científico e TecnológicoEste trabalho teve como objetivo explorar a análise de especiação de cromo, selênio e antimônio, elementos de relevância clínica e geoquímica, em amostras salinas água do mar, fluido hidrotermal e concentrado salino de hemodiálise. Tais amostras, embora ligadas a diferentes áreas de pesquisa, apresentam similaridades relacionadas à presença de espécies metálicas como contaminantes, assim como a componentes majoritários. Métodos voltamétricos foram usados na determinação dos analitos em meios de alta concentração salina sem diluição, agentes mascarantes ou etapas de separação. Uma vez que mudanças na composição da matriz em análise podem afetar a magnitude da corrente de pico para os analitos, fatores que influenciam o comportamento voltamétrico das espécies e relacionados à composição das amostras (presença de matéria orgânica dissolvida e força iônica) foram avaliados. A análise de especiação de cromo foi executada pela adsorção de complexos Cr-DTPA no eletrodo de trabalho de mercúrio seguida de redissolução aliada a um passo catalítico. Observou-se a predominância de Cr(III) em fluido hidrotermal e, de Cr(VI), em água do mar, sendo o analito determinado em concentração desprezível na amostra de concentrado salino de hemodiálise. Determinou-se selênio por uma etapa de co-eletrólise de Cu2Se com posterior redissolução catódica do composto em meio ácido. Empregou-se o pré-tratamento por irradiação UV para a redução fotolítica de espécies não-eletroativas em Se(IV), assim como para a foto-oxidação da matéria orgânica, sendo a análise de especiação aplicada a amostras reais, para as quais não se evidenciou a presença de espécies de selênio. Fez-se o uso combinado de voltametria adsortiva e voltametria anódica de redissolução, para a determinação de antimônio. Escolheu-se o reagente ácido cloranílico para a formação de complexos com Sb(III) (pH 3,0), sendo a concentração total de antimônio avaliada por voltametria de redissolução anódica em HCl 5,0 mol L-1. Observou-se a predominância de Sb(III) em fluido hidrotermal e, de Sb(V), em água do mar. Não se evidenciou a presença de espécies de antimônio na amostra de concentrado salino de hemodiálise. Levando-se em conta as espécies de cromo, selênio e antimônio, uma dependência entre corrente de pico, potencial de deposição, tempo de deposição e velocidade de varredura foi observada em todos os meios investigados. Obtiveram-se limites de detecção adequados para a determinação dos analitos, sendo que as técnicas otimizadas consistem em procedimentos simples, rápidos e de baixo custo, aplicados à análise de especiação de elementos de relevância clínica e geoquímica, em amostras de alta concentração salina, com exatidão e sensibilidade.Universidade Federal de Santa MariaBRQuímicaUFSMPrograma de Pós-Graduação em QuímicaNascimento, Paulo Cícero dohttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788664D2Rohlfes, Ana Lúcia Beckerhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701592T9Spinelli, Almirhttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781759Y0Silva, Jacqueline Arguello dahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4742294H2Yamasaki, Alzirahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701222Y5Jost, Cristiane Luisa2017-05-122017-05-122010-02-04info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfapplication/pdfJOST, Cristiane Luisa. Application of voltammetric methods to the speciation analysis of chromium, selenium and antimony in saline matrices. 2010. 143 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010.http://repositorio.ufsm.br/handle/1/4184porinfo:eu-repo/semantics/openAccessreponame:Manancial - Repositório Digital da UFSMinstname:Universidade Federal de Santa Maria (UFSM)instacron:UFSM2018-01-26T04:23:21Zoai:repositorio.ufsm.br:1/4184Biblioteca Digital de Teses e Dissertaçõeshttps://repositorio.ufsm.br/ONGhttps://repositorio.ufsm.br/oai/requestatendimento.sib@ufsm.br||tedebc@gmail.comopendoar:2018-01-26T04:23:21Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM)false |
dc.title.none.fl_str_mv |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas Application of voltammetric methods to the speciation analysis of chromium, selenium and antimony in saline matrices |
title |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas |
spellingShingle |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas Jost, Cristiane Luisa Especiação Cromo Selênio Antimônio Métodos voltamétricos Amostras salinas Speciation analysis Chromium Selenium Antimony Voltammetric methods Saline samples CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas |
title_full |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas |
title_fullStr |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas |
title_full_unstemmed |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas |
title_sort |
Aplicação de métodos voltamétricos de análise na especiação de cromo, selênio e antimônio em matrizes salinas |
author |
Jost, Cristiane Luisa |
author_facet |
Jost, Cristiane Luisa |
author_role |
author |
dc.contributor.none.fl_str_mv |
Nascimento, Paulo Cícero do http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788664D2 Rohlfes, Ana Lúcia Becker http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701592T9 Spinelli, Almir http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781759Y0 Silva, Jacqueline Arguello da http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4742294H2 Yamasaki, Alzira http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4701222Y5 |
dc.contributor.author.fl_str_mv |
Jost, Cristiane Luisa |
dc.subject.por.fl_str_mv |
Especiação Cromo Selênio Antimônio Métodos voltamétricos Amostras salinas Speciation analysis Chromium Selenium Antimony Voltammetric methods Saline samples CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
topic |
Especiação Cromo Selênio Antimônio Métodos voltamétricos Amostras salinas Speciation analysis Chromium Selenium Antimony Voltammetric methods Saline samples CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
This work aimed to explore the speciation analysis of chromium, selenium and antimony, elements of clinical and geochemical relevance, in the saline samples seawater, hydrothermal fluid and hemodialysis fluid. These samples, although linked to different research areas, have many similarities relating to their chemical compositions or the presence of metallic species as contaminants as well as major components. Voltammetric methods were used to the determination of the analytes in high salt media without the use of dilution, masking agents or separation steps. Since changes in the matrix composition may affect the analyte peak current magnitude, factors affecting the voltammetric behavior of the species related to sample composition (e.g., presence of dissolved organic matter and ionic strength) were evaluated. The chromium speciation analysis was performed by the adsorptive collection of the Cr-DTPA complex on the mercury working electrode, followed by stripping in combination to a catalytic step. Cr(III) species was found as predominant in the hydrothermal fluid sample and, Cr(VI), in the seawater sample, whereas in hemodialysis fluids an ignorable concentration was determined. Selenium was determined by the co-electrolysis of Cu2Se followed by a cathodic stripping in acidic medium. The UV-irradiation pre-treatment step was used for the reductively conversion of non-electroactive species into Se(IV) as well as for dissolved organic matter photo-oxidation, and the speciation was applied to the real sample analysis, where no selenium species were found. The combined use of adsorptive and anodic stripping voltammetry was employed for antimony determination. Chloranilic acid was chosen as the Sb(III) complex forming reagent (pH 3.0) and the total antimony concentration was evaluated by anodic stripping voltammetry in a 5.0 mol L-1 HCl medium. Sb(III) was found as the predominant species in the hydrothermal fluid sample, whereas Sb(V) is predominant in the seawater sample. No antimony species were found in the hemodialysis fluid. Concerning chromium, selenium and antimony species, remarkable peak current dependences on peak potential, deposition potential, deposition time and scan rate were observed for all investigated media. The limit of detection values were appropriate to the analytes determination, so that the present techniques consist in simple, fast and low cost procedures for the speciation analysis of elements of clinical and geochemical relevance in high salt content samples with accuracy and sensitivity. |
publishDate |
2010 |
dc.date.none.fl_str_mv |
2010-02-04 2017-05-12 2017-05-12 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
JOST, Cristiane Luisa. Application of voltammetric methods to the speciation analysis of chromium, selenium and antimony in saline matrices. 2010. 143 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/4184 |
identifier_str_mv |
JOST, Cristiane Luisa. Application of voltammetric methods to the speciation analysis of chromium, selenium and antimony in saline matrices. 2010. 143 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2010. |
url |
http://repositorio.ufsm.br/handle/1/4184 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Química UFSM Programa de Pós-Graduação em Química |
publisher.none.fl_str_mv |
Universidade Federal de Santa Maria BR Química UFSM Programa de Pós-Graduação em Química |
dc.source.none.fl_str_mv |
reponame:Manancial - Repositório Digital da UFSM instname:Universidade Federal de Santa Maria (UFSM) instacron:UFSM |
instname_str |
Universidade Federal de Santa Maria (UFSM) |
instacron_str |
UFSM |
institution |
UFSM |
reponame_str |
Manancial - Repositório Digital da UFSM |
collection |
Manancial - Repositório Digital da UFSM |
repository.name.fl_str_mv |
Manancial - Repositório Digital da UFSM - Universidade Federal de Santa Maria (UFSM) |
repository.mail.fl_str_mv |
atendimento.sib@ufsm.br||tedebc@gmail.com |
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1805922052333371392 |