PROBLEM TO BE SOLVED: To produce a separating agent for germanium efficiently separating germanium from other metals or the like by bringing chitosan into reaction with 3-chloro-1,2-proganediol in the presence of alkali and cross-linking them with chloromethyloxysilane.
SOLUTION: Chitosan and 2-chloro-1,2-propanediol are brought into reaction with at about 50 to 80°C for about 4 to 24hr in the presence of sodium hydroxide in a solvent such as a mixture of methanol-dioxane or the like, and, into the amino groups of chitosan, 2,3-dihydroxypropyl groups as side chains. This chitosan derivatives and chloromethyloxysilane are brought into reaction with at about 50 to 80°C for about 4 to 7hr in an aq. soln. of sodium hydroxide and are cross-linked to produce a 1,2-propanediol denatured chitosan derivative cross-linked body. In this way, a new separating material for germanium capable of separating germanium at a high selecting rate from the other metals or semimetals can be obtd.