Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria)
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000300013 |
Resumo: | The binding of Cu(II) to the surface of mixed species of Spirulina was studied at pH 6.0 by potentiometric titration monitored with a copper ion selective electrode. Three materials were studied: the total suspension of alga, the washing water that resulted from centrifugation of the total suspension, and the water-washed cells. The Scatchard method and the Differential Equilibrium Functions (DEF) were used for the treatment of the titration data. The Scatchard plots determined two classes of binding sites, with log K' values for stronger sites varying between 7.3 and 7.9. For the weaker sites the log K' values ranged between 3.5 and 3.9. The total concentration of binding sites were 1.6±0.1, 1.5±0.5 and 0.92±0.08 mmol g-1 for the total suspension, washing water, and washed cells, respectively. The DEF approach revealed a linear variation of log K DEF as a function of log theta (theta = degree of site occupation), with log K DEF decreasing from 9 to 4 as a consequence of increasing log theta from -2.5 to -0.25. The degree of site heterogeneity determined by the DEF approach was between 0.4 and 0.5 for the three materials studied. |
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Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria)adsorptioncomplexationcopperSpirulinapotentiometryThe binding of Cu(II) to the surface of mixed species of Spirulina was studied at pH 6.0 by potentiometric titration monitored with a copper ion selective electrode. Three materials were studied: the total suspension of alga, the washing water that resulted from centrifugation of the total suspension, and the water-washed cells. The Scatchard method and the Differential Equilibrium Functions (DEF) were used for the treatment of the titration data. The Scatchard plots determined two classes of binding sites, with log K' values for stronger sites varying between 7.3 and 7.9. For the weaker sites the log K' values ranged between 3.5 and 3.9. The total concentration of binding sites were 1.6±0.1, 1.5±0.5 and 0.92±0.08 mmol g-1 for the total suspension, washing water, and washed cells, respectively. The DEF approach revealed a linear variation of log K DEF as a function of log theta (theta = degree of site occupation), with log K DEF decreasing from 9 to 4 as a consequence of increasing log theta from -2.5 to -0.25. The degree of site heterogeneity determined by the DEF approach was between 0.4 and 0.5 for the three materials studied.Sociedade Brasileira de Química2003-05-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000300013Journal of the Brazilian Chemical Society v.14 n.3 2003reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532003000300013info:eu-repo/semantics/openAccessParmeggiani,Antonio C.Masini,Jorge C.eng2003-06-16T00:00:00Zoai:scielo:S0103-50532003000300013Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2003-06-16T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
title |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
spellingShingle |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) Parmeggiani,Antonio C. adsorption complexation copper Spirulina potentiometry |
title_short |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
title_full |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
title_fullStr |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
title_full_unstemmed |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
title_sort |
Evaluating Scatchard and Differential Equilibrium Functions to study the binding properties of Cu(II) to the surface of mixed species of lyophilized Spirulina (Cyanobacteria) |
author |
Parmeggiani,Antonio C. |
author_facet |
Parmeggiani,Antonio C. Masini,Jorge C. |
author_role |
author |
author2 |
Masini,Jorge C. |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Parmeggiani,Antonio C. Masini,Jorge C. |
dc.subject.por.fl_str_mv |
adsorption complexation copper Spirulina potentiometry |
topic |
adsorption complexation copper Spirulina potentiometry |
description |
The binding of Cu(II) to the surface of mixed species of Spirulina was studied at pH 6.0 by potentiometric titration monitored with a copper ion selective electrode. Three materials were studied: the total suspension of alga, the washing water that resulted from centrifugation of the total suspension, and the water-washed cells. The Scatchard method and the Differential Equilibrium Functions (DEF) were used for the treatment of the titration data. The Scatchard plots determined two classes of binding sites, with log K' values for stronger sites varying between 7.3 and 7.9. For the weaker sites the log K' values ranged between 3.5 and 3.9. The total concentration of binding sites were 1.6±0.1, 1.5±0.5 and 0.92±0.08 mmol g-1 for the total suspension, washing water, and washed cells, respectively. The DEF approach revealed a linear variation of log K DEF as a function of log theta (theta = degree of site occupation), with log K DEF decreasing from 9 to 4 as a consequence of increasing log theta from -2.5 to -0.25. The degree of site heterogeneity determined by the DEF approach was between 0.4 and 0.5 for the three materials studied. |
publishDate |
2003 |
dc.date.none.fl_str_mv |
2003-05-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000300013 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532003000300013 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532003000300013 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.14 n.3 2003 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318165314764800 |