2,7-Naphthalenedisulfonic acid, 5-((2,4-dihydroxy-5-((2-hydroxy-3,5-dinitrophenyl)azo)phenyl)azo)-4-hydroxy-3-((4-nitrophenyl)azo)-, disodium salt 70210-25-2 Disodium 5-((2,4-dihydroxy-5-((2-hydroxy-3,5-dinitrophenyl)azo)phenyl)azo)-4-hydroxy-3-((4-nitrophenyl)azo)naphthalene-2,7-disulphonate EINECS 274-422-0