(1,1'-Biphenyl)-2,2'-disulfonic acid, 4,4'-bis((1-(((2,4-dimethylphenyl)amino)carbonyl)-2-oxopropyl)azo)- 4,4'-Bis((1-(((2,4-dimethylphenyl)amino)carbonyl)-2-oxopropyl)azo)(1,1'-biphenyl)-2,2'-disulphonic acid 78952-69-9 EINECS 279-016-7