CHARACTERIZATION OF THE BINDING-SITES FOR AL(III) AND BE(II) IN A SAMPLE OF MARINE FULVIC-ACIDS

A sample of coastal marine fulvic acids (mfua) was studied and its bin ding site structures that form stable complexes with metal ions were i dentified. A previously developed self-modeling methodology, based on the coupling of synchronous fluorescence (SyF) spectroscopy with evolv ing factor analysis (EFA), was used for the analysis of the interactio ns between mfua and two metal ions that act as probes for binding site s, namely Be(II) and A1(III). Two types of binding site structures wer e detected, probably of the salicylic acid and catechol types. The val ues of the conditional stability constants between mfua and the two me tal ions were: for Be(II), at pH = 6, log K = 5.32(8); for A1(III), at pH = 3, log K = 5.1(2). The concentration of the corresponding bindin g sites was found to be less than one half of those found for soil ful vic acid samples.