4-Hydroxy-3-[[2-methoxy-5-methyl-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]azo]-2,7-naphthalenedisulfonic acid

4-hydroxy-3-[[2-methoxy-5-methyl-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2,7-disulphonic acid