1,5-Naphthalenedisulfonic acid, 3-((4-((4-amino-6(or 7)-sulfo-1-naphthalenyl)azo)-1-naphthalenyl)azo)-, trisodium salt 68212-33-9 EINECS 269-256-0 Trisodium 3-((4-((4-amino-6(or 7)-sulphonato-1-naphthyl)azo)-1-naphthyl)azo)naphthalene-1,5-disulphonate