In this paper, the chemical state of element sulfur in undoped, doped ferric ion samples of two typical photographic gelatins were studied by X-ray photoelectron spectroscopy. Sulfur of gelatin macromolecule contains three chemical states:
group of Metson
group of Metsox and-S-of Met. The ratio of these three chemical states reflects the relative amount of Metson, Metsox, Met in gelatin to a certain extent. Under our experimental conditions, the doped ferric ion induce the Metson to be reduced partly to Metsox.Simultaneously -CH
2- groups of gelatin are oxidized partly to
groups.