Benzoic acid, 2-​[[2-​amino-​6-​[[4'-​[(3-​carboxy-​4-​hydroxyphenyl)​azo]​-​3,​3'-​dimethoxy[1,​1'-​biphenyl]​-​4-​yl]​azo]​-​5-​hydroxy-​7-​sulfo-​1-​naphthalenyl]​azo]​-​5-​nitro-​, sodium salt (9CI)