3-((2,4(Or 2,6)Dihydroxy-5-((2-methoxy-5-sulfophenyl)azo)phenyl)azo)-4-methoxybenzenesulfonic acid, partial sodium salt 82667-03-6 Benzenesulfonic acid, 3,3'-((2,4(or 4,6)-dihydroxy-1,3-phenylene)bis(azo))bis-, sodium salt