2,7-Naphthalenedisulfonic acid, 4-((5-chloro-4-methyl-2-sulfophenyl)azo)-3-hydroxy-, barium salt (2:3) 68959-10-4 EINECS 273-396-8 Tribarium bis(4-((5-chloro-4-methyl-2-sulphonatophenyl)azo)-3-hydroxynaphthalene-2,7-disulphonate)