trisodium 4-amino-5-hydroxy-3-[[4-[(2-hydroxy-6-sulphonato-1-naphthyl)azo]phenyl]azo]-6-(phenylazo)naphthalene-2,7-disulphonate

4-Amino-5-hydroxy-3-[[4-[(2-hydroxy-6-sulfo-1-naphthalenyl)azo]phenyl]azo]-6-(phenylazo)-2,7-naphthalenedisulfonic acid trisodium salt