Argatroban Impurity 26 Argatroban Impurity 17 Ethyl (2R,4R)-1-(Nitroglycerine-nitro-L-arginyl)-4-methyl-piperidinecarboxylate hydrochloride Argatroban Impurity 56 Aniline Blue (2R,4R)-4-methyl-1-(((3-methylquinolin-8-yl)sulfonyl)-L-arginyl)piperidine-2-carboxylic acid NA Argatroban Impurity 19 3-methyl-1,2,3,4-tetrahydroquinoline-8-sulfonic acid Argatroban Impurity 88