Adsorption studies of trifluralin on chitosan and its voltammetric determination on a modified chitosan glassy carbon electrode
Autor(a) principal: | |
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Data de Publicação: | 2008 |
Outros Autores: | , , |
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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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 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
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 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
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info:eu-repo/semantics/openAccess |
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openAccess |
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