5-(benzoylamino)-4-hydroxy-3-[[2-[4-(tert-pentyl)phenoxy]phenyl]azo]naphthalene-2,7-disulphonic acid, sodium salt

5-Benzoylamino-3-[[2-[4-(1,1-dimethylpropyl)phenoxy]phenyl]azo]-4-hydroxy-2,7-naphthalenedisulfonic acid/sodium,(1:x) salt