2-Naphthalenesulfonic acid, 5-amino-8-(phenylazo)-, monosodium salt 2-Naphthalenesulfonic acid, 5-amino-8-(phenylazo)-, sodium salt 6300-23-8 EINECS 228-583-9 NSC 45552 Sodium 5-amino-8-(phenylazo)naphthalene-2-sulphonate