(3Z)-5-acetamido-3-[[4-methyl-3-(phenylsulfamoyl)phenyl]hydrazinylidene]-4-oxonaphthalene-2,7-disulfonate;disodium 5-(acetylamino)-4-hydroxy-3-[[4-methyl-3-[(phenylamino)sulphonyl]phenyl]azo]naphthalene-2,7-disulphonate;5-(Acetylamino)-4-hydroxy-3-[[4-methyl-3-[(phenylamino)sulfonyl]phenyl]azo]-2,7-naphthalenedisulfonic acid disodium salt