The importance of humin in soil characterisation: A study on Amazonian soils using different fluorescence techniques.

Autor: Tadini AM; Embrapa Agricultural Instrumentation, São Carlos, SP, Brazil; Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, SP, Brazil. Electronic address: amandatadini@hotmail.com., Nicolodelli G; Embrapa Agricultural Instrumentation, São Carlos, SP, Brazil., Mounier S; Laboratoire PROTEE, EA3819, Université de Toulon, CS 60584, 83041 Toulon CEDEX 9, France., Montes CR; Centro de Energia Nuclear na Agricultura and NUPEGEL, University of São Paulo, Piracicaba, SP, Brazil., Milori DM; Embrapa Agricultural Instrumentation, São Carlos, SP, Brazil.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2015 Dec 15; Vol. 537, pp. 152-8. Date of Electronic Publication: 2015 Aug 14.
DOI: 10.1016/j.scitotenv.2015.07.125
Abstrakt: Soil organic matter (SOM) is a complex mixture of molecules with different physicochemical properties, with humic substances (HS) being the main component as it represents around 20-50% of SOM structure. Soil of the Amazon region is considered one of the larger carbon pools of the world; thus, studies of the humic fractions are important for understanding the dynamics of organic matter (OM) in these soils. The aim of this study was to use laser-induced fluorescence spectroscopy (LIFS) and a combination of excitation-emission matrix (EEM) fluorescence with Parallel Factor Analysis (CP/PARAFAC) to assess the characteristics of humin (HU) extracted from Amazonian soils. The results obtained using LIFS showed that there was an increasing gradient of humification degree with depth, the deeper horizon presenting a higher amount of aromatic groups in the structure of HU. From the EEM, the contribution of two fluorophores with similar behaviour in the structures of HU and whole soil was assessed. Additionally, the results showed that the HU fraction might represent a larger fraction of SOM than previously thought: about 80-93% of some Amazon soils. Therefore, HU is an important humic fraction, thus indicating its role in environmental analysis, mainly in soil analysis.
(Copyright © 2015 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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