Data/hora: 22/06/2024 14:42:01

Biblioteca(s): | Embrapa Instrumentação.
Data corrente: | 13/08/2004
Data da última atualização: | 08/03/2010
Autoria: | SIMOES, M. L.; FERREIRA, J. A.; SEGNINI, A.; SILVA, W. T L da; BAYER, C.; MILORI, D. M. B. P.; MARTIN-NETO, L.
Título: | Soil tillage system effects in the formation of Hydrophobic Sites in humic acids.
Ano de publicação: | 2004
Fonte/Imprenta: | In: MARTIN-NETO, L.; MILORI, D.M.B.P.; SILVA, W.T.L. (Ed.). Humic substances and soil and water environment: International Meeting of IHSS, 12. São Carlos : Embrapa Instrumentação Agropecuária, 2004. p. 677-680.
Idioma: | Inglês
Notas: | CLASSIFICAÇÃO CDD: 630

Conteúdo:

I. INTRODUCTION 
It has been shown that humic substances (HS) play important role in many agriculture and environmental reactions. Their reactivity with inorganic and organic contaminants depend on their structures, accompanied by important functional groups, such as carboxylic (COOH), phenolic, quinone and others. Regardless of the structure models proposed, there IS a consensus about the existence of hydrophobic regions in HS structures that would be excellent sorption sites for non- polar pesticides and other anthropogenic organic chemicals and sequestration of organic carbon in 
soil (Spaccini et aI., 2002). 
Pyrene (PY) has been frequently used as a fluorescence probe in solution environments studies. PY provides a number of advantages over other fluorophores, among them, its hydrophobicity causes it to associate readily with nonpolar sites and it is a good indicator as a probe polarity in microenvironments (von Wandruszka, 1998). So, the specific probe PY can be used for understanding and for identifying hydrophobic regions in HS structures. 
The objectives of the present study are to characterize humic acids (HA) extracted from different management systems, as no-tillage and conventional tillage, from Brazilian soil and to evaluate hydrophobic interactions by using a fluorescence probe PY.

Palavras-Chave: | fluorescence spectroscopy; pyrene.
Thesaurus Nal: | humic acids.
Categoria do assunto: | --
Registro original: | Embrapa Instrumentação (CNPDIA)
Exemplares: | CNPDIA - (8335-1) - UMT - SP - -- - PROCI-04.00013 -  - 2004.00013 - DIS