disodium 3-[[4-[[4-[ethyl[(4-sulphonatophenyl)methyl]amino]phenyl]azo]-1-naphthyl]azo]benzenesulphonate

3-[[4-[[4-[Ethyl[[4-(sodiosulfo)phenyl]methyl]amino]phenyl]azo]-1-naphtyl]azo]benzenesulfonic acid sodium salt