6-imino-4-oxo-5-[2-[3-(2-sulfonatooxyethylsulfonyl)phenyl]hydrazinyl]naphthalene-2-sulfonate;dipotassium 6-amino-4-hydroxy-5-[[3-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2-sulphonate;6-Amino-4-hydroxy-5-[[3-[[2-(potassiosulfooxy)ethyl]sulfonyl]phenyl]azo]-2-naphthalenesulfonic acid potassium salt