131-80-6 Azobenzene-o,o'-disulfonic acid azo-.beta.-naphthol, sodium salt Benzenesulfonic acid, 2-[(2-hydroxy-1-naphthalenyl)azo]-5-[(2-sulfophenyl)azo]-, disodium salt Benzenesulfonic acid, 6'-[(2-hydroxy-1-naphthyl)azo]-2,3'-azodi-, disodium salt NSC10469 Scarlet Red Sulfonate