The Gold (I)-Ion Binding of Photographic Gelatin

Research sponsored by the Be lgian Ins titute of Scient ific Research in lndustry and Agronomy

Abstract

A potentiometric method is desc ribed for the measurement of the gold(I)-ion binding of photographic gelatin. At high pH the gold(I)-ion binding of the gelatin macromolecule can be explained on the basis of the amino acid composition. Histidine, lysine, arginine, tyrosine ond methionine contribute to th e binding of gold(I)-ions. At low pH however these amino acids alon e do not explain the binding of gold(I)-ions. Probably a chelate is formed.

Among the impurities pre se nt in gelatin, which are capable of increasing the pAu, sulphite must be mentioned in the first place. Attention is also drawn to th e prese nce of bactericides, such as phenol.

Notes

Research sponsored by the Be lgian Ins titute of Scient ific Research in lndustry and Agronomy