trisodium 5-[[4'-[(8-amino-1-hydroxy-3,6-disulphonato-2-naphthyl)azo]-3,3'-dimethoxy[1,1'-biphenyl]-4-yl]azo]salicylate

5-[[4'-[(8-Amino-1-hydroxy-3,6-disulfo-2-naphtyl)azo]-3,3'-dimethoxy-1,1'-biphenyl-4-yl]azo]-2-hydroxybenzoic acid trisodium salt