Comparison of marine and river water humic substances in a Patagonian environment (Argentina)

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• 作者：Mar¨ªa del Carmen Scapini ; V¨ªctor Hugo Conzonno ; Vilma Teresa Balzaretti and Alicia Fern¨¢ndez Cirelli
• 关键词：Fulvic acid ; Humic substances ; Excitation– ; emission matrices ; Chubut River ; Enga?o Bay
• 刊名：Aquatic Sciences - Research Across Boundaries
• 出版年：2010
• 出版时间：January, 2010
• 年：2010
• 卷：72
• 期：1
• 页码：1-12
• 全文大小：418.1 KB

文摘

Structural aspects of humic substances (HSs) in marine waters of Enga?o Bay (Atlantic Ocean) and water from the Chubut River (Patagonia, Argentina) were compared. The HSs were isolated, purified, and analyzed using a multiple-method approach for structural characterization: elemental analysis, nuclear magnetic resonance (13C and 1H NMR), infrared spectroscopy (FTIR), UV-visible absorption and fluorescence. Similarities between the marine and freshwater components were evaluated on the basis of N and O contents, H/C and C/N atomic ratios, infrared bands from nitrogen-containing and carboxylic groups, percentage of functional groups obtained from NMR spectra, spectral slope coefficient of absorption spectra, absorbance ratios at 250 and 365 nm (E ₂/E ₃), aromaticity, excitation–emission matrices and fluorescence quantum yield. Both the Enga?o Bay and Chubut River waters have HSs that are mainly composed of fulvic acids (FAs); although they are very similar, they may be distinguished from one another. Similarities include the predominance of aliphatic carbon content (low aromatic content); however, the water bodies differed in their content of proteins and carboxylic acids. The Enga?o Bay FAs have mainly an aquatic origin; although the Chubut River FAs suggest a similar aquagenic origin, there is also evidence of contributions from pedogenic FAs.