COMPOSITION AND ACIDIC FUNCTIONAL-GROUP CHEMISTRY OF AN AQUEOUS CHESTNUT LEAF LITTER EXTRACT

The elemental composition, amino acid distribution, IR spectrum and carboxyl group content of a chestnut leaf litter extract were determined. Proton titration data also were obtained by both continuous and discontinuous titrations. The overall titration endpoint could be identified directly by conductometric titration. Proton formation functions for the extract were computed from the 2 sets of titration data. In order to explain protonation during titration, the data were fitted to a simple chemical model by nonlinear regression analysis. From this calculation, the acidic properties of the litter extract could be modeled assuming 3 classes of acidic functional groups, with logarithms of the conditional protonation constants in the ranges: 4.00-4.25, 6.00-6.75, and 8.7-9.0.