3-((4-((8-(Benzoylamino)-1-hydroxy-3,6-disulpho-2-naphthyl)azo)-2,5-dimethoxyphenyl)azo)-4-hydroxy-5-((4-(methylsulphonyl)benzoyl)amino)naphthalene-2,7-disulphonic acid 31675-93-1 EINECS 250-757-8