EVALUATION OF ALUMINUM-SACCHARIDES COMPLEXES IN SOLUTION BY LUMINESCENCE SPECTROSCOPY

摘要

Organo-mineral associations and complexation of soil organic matter (SOM) with metals ions largely determine organic matter (OM) stability and degrad-ability (Kogel-Knabner et al, 2010). Boudot et al. (1989) showed the direct protective effect of amorphous aluminum (Al) compounds against the mineralization of various associated organics. Those results pointed to insoluble metallic hydroxides as responsible for capturing organic molecules, and preserving them from enzymatic transformation. Moreover, Masion et al. (2000) studied the flocculation of OM with Al salts and described the existence of specific binding sites for Al for given structures or ligands within the OM composition.Fluorescence spectroscopy has the required sensitivity to characterize metal ion binding properties of OM and determine its micromolar complexing capacities, i.e. to allow differentiating the binding sites or the ligand types involved in the formation ofmetal-organo complexes (Ohno et al, 2008). Thus, metal complexation with organic compounds varies fluorescence fingerprinting and can provide information on the types of metal-organic complexes, which also depend on metal concentration in solution. Carbohydrates represent about one quarter of SOM, and constitute a key component of SOM rapidly turned over. Otherwise, Bartoli and Philippy (1990) described association of exchangeable Al with OM rich in polysaccharides as one of two major types of organo-mineral associations responsible for aggregate stability. This study aimed to approach the complexation of Al with glucose (Glu) by spectrofluorometric analysis.