2-Naphthalenesulfonic acid, 7,7'-iminobis(4-hydroxy-3-(3-(oxalyamino)phenylazo))-, tetrasodium salt 68631-10-7 Acetic acid, 2,2'-(iminobis((1-hydroxy-3-sulfo-6,2-naphthalenediyl)azo-3,1-phenyleneimino))bis(2-oxo-, tetrasodium salt EINECS 271-935-1 Tetrasodium 2,2'-(iminobis((1-hydroxy-3-sulphonato-6,2-naphthalenediyl)azo-3,1-phenyleneimino))bis(2-oxoacetate)