trisodium 4-hydroxy-3-[[2-methoxy-5-methyl-4-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]-6-[(3-sulphonatophenyl)amino]naphthalene-2-sulphonate

4-Hydroxy-3-[[2-methoxy-5-methyl-4-[[2-[(sodiooxysulfonyl)oxy]ethyl]sulfonyl]phenyl]azo]-6-[[3-(sodiooxysulfonyl)phenyl]amino]-2-naphthalenesulfonic acid sodium salt