1-Naphthalenesulfonic acid, 2-amino- 2-Amino-1-naphthalenesulfonic acid 2-Naphthylamine-1-sulfonic acid 81-16-3 Kyselina 2-naftylamin-1-sulfonova Kyselina tobiasova NSC5523 Tobias acid WLN: L66J BSWQ CZ