STUDY OF ACID-BASE PROPERTIES OF FULVIC-ACIDS USING FLUORESCENCE SPECTROMETRY AND MULTIVARIATE CURVE RESOLUTION METHODS

Samples of fulvic acids obtained from cultivated calcareous soils are analyzed using acid-base titrations with spectrofluorimetric detection . Observed changes in both synchronous and emission spectra of fulvic acids when pH is changed are explained in terms of a limited number of fluorescent contributions each defined by its specific fluorescent sp ectrum and a concentration profile (species distribution) recovered fr om the multivariate curve resolution analysis of experimental data. In formation on equilibrium is estimated from concentrations of the acid- base species.