trisodium 8-[[4-[(4-aminophenyl)azo]-6-sulphonatonaphthyl]azo]-5-[(2-hydroxy-7-sulphonatonaphthyl)azo]naphthalene-2-sulphonate

8-[[4-[(4-Aminophenyl)azo]-6-sulfo-1-naphthalenyl]azo]-5-[(2-hydroxy-7-sulfo-1-naphthalenyl)azo]-2-naphthalenesulfonic acid trisodium salt