Patent ID: 9493433
Filing Date: 2016-11-15
CPC Classification: C07D,C09B,C12Q,G01N

Claim Text:
1. A method for stabilizing a leuco chromogen, comprising allowing the leuco chromogen to coexist for at least seven days in an aqueous solution comprising at least one compound selected from the group consisting of polyoxyethylene alkylamine with an alkyl having 8 to 20 carbon atoms and polyoxyethylene alkenylamine with an alkenyl having 8 to 20 carbon atoms, wherein the leuco chromogen is a phenothiazine chromogen selected from the group consisting of 10-N-(carboxymethylaminocarbonyl)-3,7-bis(dimethylamino)-10H-phenothiazine contained at a concentration of 0.0001 to 2.0 mmol/L and 10-N-methylcarbamoyl-3,7-bis(dimethylamino)-10H-phenothiazine contained at a concentration of 0.1 to 2.0 mmol/L in said aqueous solution, and the polyoxyethylene alkylamine or the polyoxyethylene alkenylamine is contained at a concentration of 0.5 to 5% in said aqueous solution.