1-Naphthalenesulfonic acid, 5-2-amino-4-4-2-(4-nitro-2-sulfophenyl)ethenyl-3-sulfophenylazoxyphenylazo-, trisodium salt

trisodium 5-[[2-amino-4-[[4-[2-(4-nitro-2-sulphonatophenyl)vinyl]-3-sulphonatophenyl]azoxy]phenyl]azo]naphthalene-1-sulphonate