2,2'-Stilbenedisulfonic acid, 4,4'-bis[(4-amino-7-sulfo- 1-naphthyl)azo]-, tetrasodium salt 2-Naphthalenesulfonic acid, 8,8'-[1,2-ethenediylbis [(3-sulfo-4,1-phenylene)azo]]bis[5-amino-, tetrasodium salt 7250-07-9 NSC34933