Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode

Detalhes bibliográficos
Autor(a) principal: Melo, Acácia Maria dos Santos
Data de Publicação: 2008
Outros Autores: Valentim, Iara Barros, Goulart, Marilia O. F., Abreu, Fabiane Caxico de
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UFS
Texto Completo: https://ri.ufs.br/handle/riufs/522
Resumo: Os estudos sobre adsorção do herbicida trifluralina (TRF) em quitosana foram realizados em batelada, usando temperaturas entre 298 e 313 K. Os resultados de adsorção ajustaram-se perfeitamente ao modelo de adsorção de Langmuir. O valor de entalpia obtido -10,2 ± 0,8 kJ mol-1 confirma que a interação TRF-quitosana é exotérmica e que o processo de adsorção é relativo à interação eletrostática entre o grupo amônio da quitosana e o dipolo negativo dos grupos substituintes de TRF, sendo dependente da força iônica. Estudos voltamétricos mostraram que TRF apresentou dois picos de redução em eletrodo de CV, ambos de natureza difusional e irreversível, referentes à redução dos grupos nitroaromáticos. A corrente do primeiro pico de redução intensificou-se no eletrodo de carbono vítreo modificado com quitosana, em comparação com o eletrodo não modificado. Isto foi atribuído à adsorção/acumulação de TRF em quitosana. A corrente de redução em voltametria de pulso diferencial foi proporcional à concentração de TRF na faixa de 2,49 × 10-7 a 5,79 × 10-6 mol L-1, com limite de detecção de 7,45 × 10-8 mol L-1._______________________________________________________________________________ ABSTRACT: The studies about adsorption of the herbicide trifluralin (TRF), on chitosan, were carried out by batch methods using temperatures from 298 up to 313 K. The adsorption results were well fitted to Langmuir adsorption model. The obtained enthalpic value of -10.2 ± 0.8 kJ mol-1 confirms that the TRF-chitosan interaction is exothermic and that the adsorption process is relative to electrostatic interaction between the ammonium group of chitosan and the negative dipole of the substituent groups of TRF, being dependent on ionic strength. Voltammetric studies showed that TRF exhibited two irreversible, diffusional reduction waves related to the reduction of the nitroaromatic groups. The current of the first reduction peak intensified on the chitosan-modified glassy carbon electrode in comparison with the unmodified one. This was attributed to the adsorption/accumulation of TRF on chitosan. The reduction current, using Differential Pulse Voltammetry, was proportional to the concentration of TRF in the range of 2.49 ×10-7 to 5.79 ×10-6 mol L-1, with a detection limit of 7.45 × 10-8 mol L-1.
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spelling Melo, Acácia Maria dos SantosValentim, Iara BarrosGoulart, Marilia O. F.Abreu, Fabiane Caxico de2013-05-10T17:58:06Z2013-05-10T17:58:06Z2008MELO, A. M. S. et al. Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode. Journal of the Brazilian Chemical Society, São Paulo, v. 19, n. 4, p. 704-710, 2008. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400014&lng=en&nrm=iso>. Acesso em: 10 maio 2013.0103-5053https://ri.ufs.br/handle/riufs/522Creative Commons Attribution LicenseOs estudos sobre adsorção do herbicida trifluralina (TRF) em quitosana foram realizados em batelada, usando temperaturas entre 298 e 313 K. Os resultados de adsorção ajustaram-se perfeitamente ao modelo de adsorção de Langmuir. O valor de entalpia obtido -10,2 ± 0,8 kJ mol-1 confirma que a interação TRF-quitosana é exotérmica e que o processo de adsorção é relativo à interação eletrostática entre o grupo amônio da quitosana e o dipolo negativo dos grupos substituintes de TRF, sendo dependente da força iônica. Estudos voltamétricos mostraram que TRF apresentou dois picos de redução em eletrodo de CV, ambos de natureza difusional e irreversível, referentes à redução dos grupos nitroaromáticos. A corrente do primeiro pico de redução intensificou-se no eletrodo de carbono vítreo modificado com quitosana, em comparação com o eletrodo não modificado. Isto foi atribuído à adsorção/acumulação de TRF em quitosana. A corrente de redução em voltametria de pulso diferencial foi proporcional à concentração de TRF na faixa de 2,49 × 10-7 a 5,79 × 10-6 mol L-1, com limite de detecção de 7,45 × 10-8 mol L-1._______________________________________________________________________________ ABSTRACT: The studies about adsorption of the herbicide trifluralin (TRF), on chitosan, were carried out by batch methods using temperatures from 298 up to 313 K. The adsorption results were well fitted to Langmuir adsorption model. The obtained enthalpic value of -10.2 ± 0.8 kJ mol-1 confirms that the TRF-chitosan interaction is exothermic and that the adsorption process is relative to electrostatic interaction between the ammonium group of chitosan and the negative dipole of the substituent groups of TRF, being dependent on ionic strength. Voltammetric studies showed that TRF exhibited two irreversible, diffusional reduction waves related to the reduction of the nitroaromatic groups. The current of the first reduction peak intensified on the chitosan-modified glassy carbon electrode in comparison with the unmodified one. This was attributed to the adsorption/accumulation of TRF on chitosan. The reduction current, using Differential Pulse Voltammetry, was proportional to the concentration of TRF in the range of 2.49 ×10-7 to 5.79 ×10-6 mol L-1, with a detection limit of 7.45 × 10-8 mol L-1.QuitosanaTrifluralinaAdsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrodeinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleengreponame:Repositório Institucional da UFSinstname:Universidade Federal de Sergipe (UFS)instacron:UFSinfo:eu-repo/semantics/openAccessTHUMBNAILAdsorptionTrifluralinChitosan.pdf.jpgAdsorptionTrifluralinChitosan.pdf.jpgGenerated Thumbnailimage/jpeg1577https://ri.ufs.br/jspui/bitstream/riufs/522/4/AdsorptionTrifluralinChitosan.pdf.jpgcf81179b9e3eca1e2fb2790299f9e080MD54ORIGINALAdsorptionTrifluralinChitosan.pdfAdsorptionTrifluralinChitosan.pdfapplication/pdf319709https://ri.ufs.br/jspui/bitstream/riufs/522/1/AdsorptionTrifluralinChitosan.pdfba556dc6cad7a63ed3debf3d5a274131MD51LICENSElicense.txtlicense.txttext/plain; charset=utf-81748https://ri.ufs.br/jspui/bitstream/riufs/522/2/license.txt8a4605be74aa9ea9d79846c1fba20a33MD52TEXTAdsorptionTrifluralinChitosan.pdf.txtAdsorptionTrifluralinChitosan.pdf.txtExtracted texttext/plain26560https://ri.ufs.br/jspui/bitstream/riufs/522/3/AdsorptionTrifluralinChitosan.pdf.txtb4bb588f6f25eff506959c93dff4e54bMD53riufs/5222013-05-11 02:00:07.195oai:ufs.br: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Repositório InstitucionalPUBhttps://ri.ufs.br/oai/requestrepositorio@academico.ufs.bropendoar:2013-05-11T05:00:07Repositório Institucional da UFS - Universidade Federal de Sergipe (UFS)false
dc.title.pt_BR.fl_str_mv Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
title Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
spellingShingle Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
Melo, Acácia Maria dos Santos
Quitosana
Trifluralina
title_short Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
title_full Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
title_fullStr Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
title_full_unstemmed Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
title_sort Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
author Melo, Acácia Maria dos Santos
author_facet Melo, Acácia Maria dos Santos
Valentim, Iara Barros
Goulart, Marilia O. F.
Abreu, Fabiane Caxico de
author_role author
author2 Valentim, Iara Barros
Goulart, Marilia O. F.
Abreu, Fabiane Caxico de
author2_role author
author
author
dc.contributor.author.fl_str_mv Melo, Acácia Maria dos Santos
Valentim, Iara Barros
Goulart, Marilia O. F.
Abreu, Fabiane Caxico de
dc.subject.por.fl_str_mv Quitosana
Trifluralina
topic Quitosana
Trifluralina
description Os estudos sobre adsorção do herbicida trifluralina (TRF) em quitosana foram realizados em batelada, usando temperaturas entre 298 e 313 K. Os resultados de adsorção ajustaram-se perfeitamente ao modelo de adsorção de Langmuir. O valor de entalpia obtido -10,2 ± 0,8 kJ mol-1 confirma que a interação TRF-quitosana é exotérmica e que o processo de adsorção é relativo à interação eletrostática entre o grupo amônio da quitosana e o dipolo negativo dos grupos substituintes de TRF, sendo dependente da força iônica. Estudos voltamétricos mostraram que TRF apresentou dois picos de redução em eletrodo de CV, ambos de natureza difusional e irreversível, referentes à redução dos grupos nitroaromáticos. A corrente do primeiro pico de redução intensificou-se no eletrodo de carbono vítreo modificado com quitosana, em comparação com o eletrodo não modificado. Isto foi atribuído à adsorção/acumulação de TRF em quitosana. A corrente de redução em voltametria de pulso diferencial foi proporcional à concentração de TRF na faixa de 2,49 × 10-7 a 5,79 × 10-6 mol L-1, com limite de detecção de 7,45 × 10-8 mol L-1._______________________________________________________________________________ ABSTRACT: The studies about adsorption of the herbicide trifluralin (TRF), on chitosan, were carried out by batch methods using temperatures from 298 up to 313 K. The adsorption results were well fitted to Langmuir adsorption model. The obtained enthalpic value of -10.2 ± 0.8 kJ mol-1 confirms that the TRF-chitosan interaction is exothermic and that the adsorption process is relative to electrostatic interaction between the ammonium group of chitosan and the negative dipole of the substituent groups of TRF, being dependent on ionic strength. Voltammetric studies showed that TRF exhibited two irreversible, diffusional reduction waves related to the reduction of the nitroaromatic groups. The current of the first reduction peak intensified on the chitosan-modified glassy carbon electrode in comparison with the unmodified one. This was attributed to the adsorption/accumulation of TRF on chitosan. The reduction current, using Differential Pulse Voltammetry, was proportional to the concentration of TRF in the range of 2.49 ×10-7 to 5.79 ×10-6 mol L-1, with a detection limit of 7.45 × 10-8 mol L-1.
publishDate 2008
dc.date.issued.fl_str_mv 2008
dc.date.accessioned.fl_str_mv 2013-05-10T17:58:06Z
dc.date.available.fl_str_mv 2013-05-10T17:58:06Z
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dc.identifier.citation.fl_str_mv MELO, A. M. S. et al. Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode. Journal of the Brazilian Chemical Society, São Paulo, v. 19, n. 4, p. 704-710, 2008. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400014&lng=en&nrm=iso>. Acesso em: 10 maio 2013.
dc.identifier.uri.fl_str_mv https://ri.ufs.br/handle/riufs/522
dc.identifier.issn.none.fl_str_mv 0103-5053
dc.identifier.license.pt_BR.fl_str_mv Creative Commons Attribution License
identifier_str_mv MELO, A. M. S. et al. Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode. Journal of the Brazilian Chemical Society, São Paulo, v. 19, n. 4, p. 704-710, 2008. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000400014&lng=en&nrm=iso>. Acesso em: 10 maio 2013.
0103-5053
Creative Commons Attribution License
url https://ri.ufs.br/handle/riufs/522
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