a mixture of: 5-[(4-[(7-amino-1-hydroxy-3-sulfo-2-naphthyl) azo]-2,5-diethoxyphenyl)azo]-2-[(3-phosphonophenyl)azo]benzoic acid and 5-[(4-[(7-amino-1-hydroxy-3-sulfo-2-naphthyl)azo]-2,5-diethoxyphenyl)azo]-3-[(3-phosphonophenyl) azo]benzoic acid
miscela di: acido 5-[(4-[(7-ammino-1-idrossi-3-solfo-2-naftil)azo]-2,5-dietossifenil)azo]-2-[(3-fosfonofenil)azo] benzoico e 5-[(4-[(7-ammino-1-idrossi-3-solfo-2-naftil)azo]-2,5-dietossifenil)azo]-3-[(3-fosfonofenil)azo] benzoico