2-Naphthalenesulfonic acid, 7,7'-(carbonyldiimino)bis(4-hydroxy-3-((6-sulfo-2-naphthalenyl)azo)-, tetrasodium salt 28706-25-4 7,7'-(Carbonyldiimino)bis(4-hydroxy-3-((6-sulfonaphthalen-2-yl))azo)-2-naphthalenesulfonic acid, tetrasodium salt 7,7'-Ureylenebis(4-hydroxy-3-((6-sulfo-2-naphthyl)azo)-2-naphthalenesulfonic acid), tetrasodium salt EINECS 249-171-5 Tetrasodium 7,7'-(carbonyldiimino)bis(4-hydroxy-3-((6-sulphonato-2-naphthyl)azo)naphthalene-2-sulphonate)