DIAZ Monica Mabel
congresos y reuniones científicas
Study Of Copper Binding By Humic Acids From An Acidic Pond Using Fluorescence Spectroscopy.
CABRERA, JM.; DIAZ, MM.; GARCÍA EINSCHLAG, FS.
Congreso; 17th Meeting of the International Humic Substances Society; 2014
International Humic Substances Society
Fluorescence spectroscopy was applied to the study of dissolved organic matter (DOM) for the last 4 decades (Aiken et al., 1985; Sensei et al., 1991; Ferrari & Mingazzini, 1995; Coble, 1996). The 3D excitation-emission fluorescence matrices (EEFM) allowed to characterize structural properties by means of identifying different fluorophoric components, like quinones, catechols, phtalates, phenol, amines and salicilates. Several authors suggested that, variation on the flurophores proportion can be turn into a characteristic fingerprint for the organic matter extracted from different places (Coble et al., 1990; Mopper & Schultz, 1993; Ahmad & Reynolds, 1995 Ryan et al., 1996; Baker, 2001; Baker & Spencer, 2004). Humic acid (HA) metal complexing capacity by the above-mentioned functional groups can be studied by EEFM. Given that fluorescence quenching (or enhancing) may arise when metals are bounded to the fluorophore (Philpot & Vodacek, 1989; Luster et al., 1996; Ryan et al., 1996; Wu et al., 2011), apparent binding constants can be calculated (Ryan & Weber, 1982). Caviahues sedimentary humic acids showed high affinity for Cu+2. Although this metal is mostly found in the pyritic fraction, should changes in REDOX conditions occur (e.g. by mixing due to sismic activity) the potentially solubilized copper will be fully complexed due to the high affinity constants involved and the fact that HAs are in excess when compared to metal concentration.