3-[[5-[(ethylphenylamino)sulphonyl]-2-phenoxyphenyl]azo]-4-hydroxy-5-[[(p-tolyl)sulphonyl]amino]naphthalene-2,7-disulphonic acid

3-[[5-[[Ethyl(phenyl)amino]sulfonyl]-2-phenoxyphenyl]azo]-4-hydroxy-5-[[(4-methylphenyl)sulfonyl]amino]-2,7-naphthalenedisulfonic acid