REACTION OF GELATIN WITH Cr(III), Al(III) AND Fe(III): INVESTIGATION BY SPECTROFLUORIMETRY

The fluorescence quenching of gelatin with Fe3+/Cr3+/Al3+ was studied by spectrolluorimetry, and the reaction mechanism was analyzed with the Stern-Volmer equation. Meanwhile, the number of binding sites, the binding constant, the thermodynamic functions of the reaction between gelatin and Fell were calculated. The results Suggest that the fluorescence quenching of the gelatin is static quenching with Fell, dynamic quenching with Cr3+, but no quenching with Al3+. As a result, it is selective for the metal tanning agents complexing to the collagen. Also, the binding ratio of the gelatin and Fell is about 1: 1, Moreover, the thermodynamic functions (Delta Hm(theta) and Delta Sm-theta) in the reaction indicate that the reaction of the gelatin and Fe3+ is endothermal and the entropy increases in the process. The study should help to understand the mineral tanning machanism.