METHOD OF STABILIZING OXIDATION COLOR FORMER

摘要

A method of stabilizing an oxidation color former in a solution is provided. N-(carboxymethylaminocarbonyl)-4,4'-bis(dimethylamino) diphenylamine sodium salt as an oxidation color former is stabilized by providing it with at least one of a fructosyl amino acid oxidase (FAOD) and a peroxidase (POD) in the solution. The concentration of the FAOD is in the range from 0.01 to 1.0 g/l or 1 to 100 KU/l, and the concentration of the POD is in the range from 0.01 to 1.0 g/l or 1 to 100 KU/l. <IMAGE>