2-Naphthalenesulfonic acid, 7,7'-(carbonyldiimino)bis(4-hydroxy-3-((2-methyl-4-sulfophenyl)azo)-, tetrasodium salt 2-Naphthalenesulfonic acid, 7,7'-ureylenebis(4-hydroxy-3-((4-sulfo-o-tolyl)azo)-, tetrasodium salt 28706-33-4 7,7'-Carbonyldiimino)bis(4-hydroxy-3-(2-methyl-4-sulfophenyl)azo)-2-naphthalenesulfonic acid, tetrasodium salt EINECS 249-172-0 Tetrasodium 7,7'-(carbonyldiimino)bis(4-hydroxy-3-((2-methyl-4-sulphonatophenyl)azo)naphthalene-2-sulphonate)