2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-3-((4-nitrophenyl)azo)-, disodium salt 4-Amino-5-hydroxy-3-((4-nitrophenyl)azo)-2,7-naphthalenedisulfonic acid, disodium salt 56431-61-9 Disodium 4-amino-5-hydroxy-3-(4-nitrophenylazo)naphthalene-2,7-disulphonate EINECS 260-178-2