disodium 7-(acetylamino)-4-hydroxy-3-[[2-methyl-4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulphonate

7-Acetylamino-4-hydroxy-3-[[2-methyl-4-[(4-sodiooxysulfonylphenyl)azo]phenyl]azo]-2-naphthalenesulfonic acid sodium salt