Conductimetric analysis of the ion binding properties of three leaf extracts of chestnut ( Castanea sativa), Eucalyptus ( Eucalyptus globulus) and oak ( Quercus robur)

Abstract

Humic materials extracted from tree leaves of chestnut ( Castanea sativa), eucalyptus ( Eucalyptus globulus) and oak ( Quercus robur) were analyzed by performing conductimetric titrations. Values between about 84 and 236 μS cm −1 for the molar conductivity and between 0.42 and 0.74 for the charge distribution parameter were obtained when the concentrations of the extract are increased from 40 to 100 mg 1 −1. These variations were explained by using the counterion condensation theory, and the distance between the charged groups of the polyions, the volume of the counterion condensation and the Debye-Hückel potential were also calculated.