1,5-Naphthalenedisulfonic acid, 3,3'-(carbonylbis(imino(3-methoxy-4,1-phenylene)azo))bis-, tetrasodium salt 1,5-Naphthalenedisulfonic acid, 3,3'-(carbonylbis(imino(5-methoxy-4,1-phenylene)azo)bis-, tetrasodium salt 28706-22-1 EINECS 249-169-4 Tetrasodium 3,3'-(carbonylbis(imino(3-methoxy-4,1-phenylene)azo))bisnaphthalene-1,5-disulphonate