2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy- 4-Amino-5-hydroxy-2,7-naphthalenedisulfonic acid 90-20-0 C.I. 35570 H Acid H-Acid Kyselina 1-amino-8-naftol-3,6-disulfonova Kyselina H NSC190492 WLN: L66J BZ DSWQ HSWQ JQ