2,7-Naphthalenedisulfonic acid, 4-amino-3-((2,5-disulfophenyl)azo)-5-hydroxy-6-((3-phosphonophenyl)azo)-, tetrasodium salt 4-Amino-5-hydroxy-6-((3-phosphonophenyl)azo)-3-((2,5-disulfophenyl)azo)-2,7-naphthalenedisulfonic acid, tetrasodium salt 68110-25-8 EINECS 268-513-4 Tetrasodium hydrogen 4-amino-3-((2,5-disulphonatophenyl)azo)-5-hydroxy-6-((m-phosphonatophenyl)azo)naphthalene-2,7-disulphonate