2-Naphthalenesulfonic acid, 5-((2-hydroxy-1-naphthalenyl)azo)-, monosodium salt 2-Naphthalenesulfonic acid, 5-((2-hydroxy-1-naphthalenyl)azo)-, sodium salt 68133-05-1 EINECS 268-663-0 Sodium 5-((2-hydroxy-1-naphthyl)azo)naphthalene-2-sulphonate