Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents

Detalhes bibliográficos
Autor(a) principal: Rocha,J.C.
Data de Publicação: 1999
Outros Autores: Sargentini Jr,É., Toscano,I.A.S., Rosa,A.H., Burba,P.
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=S0103-50531999000300002
Resumo: The aquatic humic substances investigated in this study were conventionally isolated from Rio Negro waters - Amazonas State/Brazil by means of the collector XAD 8. Molecular spectroscopy investigations of these humic substances using ¹H-NMR and 13C-NMR indicated the presence of high aromaticity with few substituents, small amounts of carboxylic carbon, and an aliphatic/aromatic ratio of 1:1. The relatively high UV-VIS absorbance E350/E450 ratio suggested the presence of relatively large proportions of aliphatic structures. Moreover, using a five-stage tangential-flow ultrafiltration (UF) device, the molecular-size distribution of the isolated humic substances was characterized. The fractionation patterns showed that metal traces remaining in humic substances after their XAD 8 isolation have different size distributions. For instance, Mn, Cu, Cd and Ni quantified by ICP-AES were preferably found in the high molecular-weight fractions (10-100 kDa).
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spelling Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contentsaquatic humic substancesRio Negronuclear magnetic resonancetrace metalsmolecular-size distributionmultistage ultrafiltrationThe aquatic humic substances investigated in this study were conventionally isolated from Rio Negro waters - Amazonas State/Brazil by means of the collector XAD 8. Molecular spectroscopy investigations of these humic substances using ¹H-NMR and 13C-NMR indicated the presence of high aromaticity with few substituents, small amounts of carboxylic carbon, and an aliphatic/aromatic ratio of 1:1. The relatively high UV-VIS absorbance E350/E450 ratio suggested the presence of relatively large proportions of aliphatic structures. Moreover, using a five-stage tangential-flow ultrafiltration (UF) device, the molecular-size distribution of the isolated humic substances was characterized. The fractionation patterns showed that metal traces remaining in humic substances after their XAD 8 isolation have different size distributions. For instance, Mn, Cu, Cd and Ni quantified by ICP-AES were preferably found in the high molecular-weight fractions (10-100 kDa).Sociedade Brasileira de Química1999-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000300002Journal of the Brazilian Chemical Society v.10 n.3 1999reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50531999000300002info:eu-repo/semantics/openAccessRocha,J.C.Sargentini Jr,É.Toscano,I.A.S.Rosa,A.H.Burba,P.eng2002-10-23T00:00:00Zoai:scielo:S0103-50531999000300002Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2002-10-23T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false
dc.title.none.fl_str_mv Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
title Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
spellingShingle Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
Rocha,J.C.
aquatic humic substances
Rio Negro
nuclear magnetic resonance
trace metals
molecular-size distribution
multistage ultrafiltration
title_short Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
title_full Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
title_fullStr Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
title_full_unstemmed Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
title_sort Multi-method Study on Aquatic Humic Substances from the "Rio Negro" - Amazonas State/Brazil: Emphasis on Molecular-Size Classification of their Metal Contents
author Rocha,J.C.
author_facet Rocha,J.C.
Sargentini Jr,É.
Toscano,I.A.S.
Rosa,A.H.
Burba,P.
author_role author
author2 Sargentini Jr,É.
Toscano,I.A.S.
Rosa,A.H.
Burba,P.
author2_role author
author
author
author
dc.contributor.author.fl_str_mv Rocha,J.C.
Sargentini Jr,É.
Toscano,I.A.S.
Rosa,A.H.
Burba,P.
dc.subject.por.fl_str_mv aquatic humic substances
Rio Negro
nuclear magnetic resonance
trace metals
molecular-size distribution
multistage ultrafiltration
topic aquatic humic substances
Rio Negro
nuclear magnetic resonance
trace metals
molecular-size distribution
multistage ultrafiltration
description The aquatic humic substances investigated in this study were conventionally isolated from Rio Negro waters - Amazonas State/Brazil by means of the collector XAD 8. Molecular spectroscopy investigations of these humic substances using ¹H-NMR and 13C-NMR indicated the presence of high aromaticity with few substituents, small amounts of carboxylic carbon, and an aliphatic/aromatic ratio of 1:1. The relatively high UV-VIS absorbance E350/E450 ratio suggested the presence of relatively large proportions of aliphatic structures. Moreover, using a five-stage tangential-flow ultrafiltration (UF) device, the molecular-size distribution of the isolated humic substances was characterized. The fractionation patterns showed that metal traces remaining in humic substances after their XAD 8 isolation have different size distributions. For instance, Mn, Cu, Cd and Ni quantified by ICP-AES were preferably found in the high molecular-weight fractions (10-100 kDa).
publishDate 1999
dc.date.none.fl_str_mv 1999-01-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
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status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000300002
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531999000300002
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0103-50531999000300002
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.10 n.3 1999
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
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