disodium 7,7'-[azobis(4,1-phenylenecarbonylimino)]bis[4-hydroxy-3-[[2-hydroxy-5-(methylsulphonyl)phenyl]azo]naphthalene-2-sulphonate]

7,7'-[Azobis(4,1-phenylenecarbonylimino)]bis[4-hydroxy-3-[2-hydroxy-5-(methylsulfonyl)phenylazo]-2-naphthalenesulfonic acid]disodium salt