.alpha.-Naphthylamine-4-sulfonic acid .alpha.-Naphthylamine-p-sulfonic acid 1,4-Naphthionic acid 1-Amino-4-naphthalenesulfonic acid 1-Amino-4-sulfonaphthalene 1-Aminonaphthalene-4-sulfonic acid 1-Naphthalenesulfonic acid, 4-amino- 1-Naphthylamine-4-sulfonic acid 4-AMINO-1-NAPHTHALENESULFONIC ACID 84-86-6 NSC4155 Naphthionic acid Piria's acid Usaf m-5 WLN: L66J BZ ESWQ