4-[[4-Chloro-6-[4-[[2-(sulfooxy)ethyl]sulfonyl]anilino]-1,3,5-triazine-2-yl]amino]-5-hydroxy-6-[(2-sulfophenyl)azo]-1,7-naphthalenedisulfonic acid/sodium,(1:x) salt

4-[[4-chloro-6-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]amino]-1,3,5-triazin-2-yl]amino]-5-hydroxy-6-[(2-sulphophenyl)azo]naphthalene-1,7-disulphonic acid, sodium salt