2,7-Naphthalenedisulfonic acid, 4,4'-((3,3'-dimethoxy(1,1'-biphenyl)-4,4'-diyl)bis(azo))bis(3-hydroxy-, tetrasodium salt 65151-33-9 EINECS 265-533-5 Tetrasodium 4,4'-((3,3'-dimethoxy(1,1'-biphenyl)-4,4'-diyl)bis(azo))bis(3-hydroxynaphthalene-2,7-disulphonate)