2,7-naphthalenedisulfonic acid, 3-hydroxy-4-nitroso-, sodium salt (1:2); 525-05-3; Sodium Salt of 1-Nitroso-2-hydroxynaphthalene-3,6-disulfonic Acid; disodium 3-hydroxy-4-nitrosonaphthalene-2,7-disulfonate; Nitroso-R-salt; 1-Nitroso-2-naphthol-3,6-disulphonic acid disodium salt