Characterization of typical aquatic humic substances in areas of sugarcane cultivation in Brazil using tetramethylammonium hydroxide thermochemolysis

Autor(es)

Tadini, A. M. ^[1] ; Constantino, I. C. ^[1] ; Nuzzo, A. ^[2] ; Spaccini, R. ^[2] ; Piccolo, A. ^[2] ; Moreira, A. B. ^[1] ; Bisinoti, M. C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Biociencias Letras & Ciencias Exatas, Dept Quim & Ciencias Ambientais, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Naples Federico II, Dipartimento Sci Suolo Pianta & Ambiente, I-80055 Portici - Italy

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 518, p. 201-208, JUN 15 2015.
• Citações Web of Science: 5

Resumo

Aquatic humic substances (AHSs) differ from one environment to another depending on land use and occupation. In addition, the effects of planting sugarcane on AHSs are not well known. Thus, the aim of this study was to characterize AHSs extracted from a river in a typical region of sugarcane cultivation during dry and rainy seasons. The main characteristics of the AHSs were obtained using Fourier transformation infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and off-line pyrolysis coupled with gas chromatography and mass spectrometry (off-line tetramethylammonium hydroxide (TMAH)-GC-MS-thermochemolysis). The FTIR and NMR results were used to infer that no distinctions occurred between the sampling periods. The samples were composed of aromatic groups that were potentially associated with the presence of residual vegetable materials (lignin). The results of the off-line TMAH-GC-MS-thermochemolysis indicated that the structures of the AHSs had uniform compositions that were rich in fatty acid methyl esters (FAMEs), polysaccharide derivatives, aliphatic biopolymers derived from plants, long hydrocarbon chains, branched alkyl groups and methylene carbons. Thus, the results showed that the AHSs obtained from the sugarcane cultivation area during the crop period mainly consisted of resistant aliphatic hydrocarbons, which are derivatives of lignin and FAMEs in compounds rich in humic acid. Therefore, we concluded that sugarcane cultivation produces changes in AHSs because greater amounts of lignin derivatives were observed during the dry season, corresponding to sugarcane cultivation. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 10/13879-2 - Interação entre substâncias húmicas e íons cromo e proposta de um indicador de matéria orgânica lábil
• Beneficiário: Amanda Maria Tadini
• Modalidade de apoio: Bolsas no Brasil - Mestrado
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• Beneficiário: Márcia Cristina Bisinoti
• Modalidade de apoio: Auxílio à Pesquisa - Regular
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• Beneficiário: Márcia Cristina Bisinoti
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/06403-7 - Caracterização das substâncias húmicas aquáticas extraídas do Rio Preto
• Beneficiário: Amanda Maria Tadini
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Mestrado