Abstract

A hexaaquochromium solution was masked with formate, acetate, and oxalate. The masked chromium complexes were separated by ion exchange chromatography. Hide powder was tanned with the masked chromium complexes. The affinity of the masked chromium complexes for collagen varied with each individual complex. Among various kinds of masked chromium complexes, formatochromium complexes with a charge corresponding to +3 had the highest affinity for collagen at high pH and formatochromium complexes with a charge corresponding to +2 were second in affinity. Acetatochromium complexes with a charge corresponding to +3 followed these complexes. Noncationic acetato- and oxalato-chromium complexes had low affinity.