6252-57-9 EINECS 228-374-2 Tetrasodium 4-hydroxy-5-((4-((4-((1-hydroxy-6-(phenylamino)-3-sulphonato-2-naphthyl)azo)-6-sulphonatonaphthyl)azo)naphthyl)azo)naphthalene-2,7-disulphonate