(4-((1,3-Disulfonaphthalene-7-yl)azo)benzeneamino)methanesulfonic acid, trisodium salt 1,3-Naphthalenedisulfonic acid, 7-((4-((sulfomethyl)amino)phenyl)azo)-, trisodium salt 68084-13-9 EINECS 268-425-6 Trisodium 7-((4-((sulphonatomethyl)amino)phenyl)azo)naphthalene-1,3-disulphonate