74432-30-7 EINECS 277-872-6 Tetrasodium (mu-((3,3'-((3,3'-dihydroxy(1,1'-biphenyl)-4,4'-diyl)bis(azo))bis(4-hydroxy-6-(3-sulphoanilino)naphthalene-2-sulphonato))(8-)))dicuprate(4-)