4-hydroxy-7-[[1-oxo-3-(phenylsulphonyl)propyl]amino]-3-[(4-sulphophenyl)azo]naphthalene-2-sulphonic acid, potassium sodium salt

4-Hydroxy-7-[[1-oxo-3-(phenylsulfonyl)propyl]amino]-3-[(4-sulfophenyl)azo]-2-naphthalenesulfonic acid/potassium/sodium,(1:x:x) salt