CAS 23647-14-5 appears in our catalog under these names: SPADNS, 2–(4–Sulfonylphenyl azochromic acid trisodium salt, indicator, SPADNS , p-Sulfophenylazochromotropic acid trisodium salt, Trisodium 2-(4-Sulfophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonate, >95.0%(HPLC). Offered by: Chemat, GLPBio, Thermo Scientific (Alfa Aesar), Biosynth, TCI. Available pack sizes: 10g, 50g, 100g, 25g, 5g, 1g.