Reaction Of Gelatin With Cr(iii), Al(iii) And Fe(iii): Investigation By Spectrofluorimetry

摘要

The fluorescence quenching of gelatin with Fe~(3+)/Cr~(3+)/Al~(3+) was studied by spectrofluorimetry, 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 Fe~(3+) were calculated. The results suggest that the fluorescence quenching of the gelatin is static quenching with Fe~(3+), dynamic quenching with Cr~(3+), but no quenching with Al~(3+). As a result, it is selective for the metal tanning agents complexing to the collagen. Also, the binding ratio of the gelatin and Fe~(3+) is about 1:1, Moreover, the thermodynamic functions (△Hm~θ and ASm~θ) in the reaction indicate that the reaction of the gelatin and Fe~(3+) is endothermal and the entropy increases in the process. The study should help to understand the mineral tanning machanism.