5-((2-Amino-4-hydroxy-5-((4-((4-nitro-2-sulphophenyl)amino)phenyl)azo)phenyl)azo)-4-hydroxy-3-((4-((4-nitro-2-sulphophenyl)amino)phenyl)azo)naphthalene-2,7-disulphonic acid 94021-34-8 EINECS 301-428-3