Synonyms: Copper,[m-[[tetrahydrogen3,3'-[azoxybis[(2-hydroxy-p-phenylene)azo]]bis[4-hydroxy-6-(m-sulfoanilino)-2-naphthalenesulfonato]](4-)]]di-,tetrasodium salt (8CI); 2-Naphthalenesulfonic acid,3,3'-[azoxybis[(2-hydroxy-1,4-phenylene)azo]]bis[4-hydroxy-6-[(3-sulfophenyl)amino]-,copper complex