ToME: the Tales of Maj'Eyal

I have an item that is supposed to drop in daikara but i cleared the whole zone and didn't get it

Does this mean I cannot complete the alchemist quest that requires it, is this common?

item is Vial of Fire Wyrm Saliva - Daikara, Gorbat Pride

nevermind, looks like it was on the derth storm quest that you get it

Those are only the common places to find that. Adventurers may have some lying around, and there's at least one more slightly spoilery place you could look.