1-Naphthalenesulfonic acid, 3-((7-((4'-((1,8-dihydroxy-4-sulfo-2-naphthalenyl)azo)-3,3'-dimethyl (1,1'-biphenyl)-4-yl)azo)-8-hydroxy-6-sulfo-2-naphthalenyl)azo)-4,5-dihydroxy-, trisodium salt 7082-31-7