disodium 5-[[4-[bis(2-hydroxyethyl)amino]phenyl]azo]-8-[(4-sulphonatophenyl)azo]naphthalene-2-sulphonate

5-[[4-[Bis(2-hydroxyethyl)amino]phenyl]azo]-8-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid disodium salt