2-[[7-acetamido-1-hydroxy-3-sulpho-2-naphthyl]azo]-6-[[2-(sulphooxy)ethyl]sulphonyl]naphthalene-1-sulphonic acid, sodium salt

2-[[7-(Acetylamino)-1-hydroxy-3-sulfonaphthalene-2-yl]azo]-6-[[2-(sulfooxy)ethyl]sulfonyl]-1-naphthalenesulfonic acid/sodium,(1:x) salt