Of course, that pool of liquid could already carry the "serial numbers" that give it its abstract worth. Quark already knows the stuff is "money latinum" so he doesn't have to worry about it being uncoded "ordinary latinum" that would only attain value through a process analogous to the printing of bills.
Well, to do that, you'd have to imprint every individual atom (latinum being metallic, there would be no "molecules" per se
) with its' own unique serial number - after all, if somewhere around 5-10ml constitutes ~100 bricks, how little is in a slip of GPL? Especially if you can extract that latinum from the slip and physically place it, along with similarly-extracted latinum, in new gold bricks to then make a whole brick of GPL while the brick holds the complete monetary value of a brick. And once you've then done that - a fiendish technical challenge, but probably not impossible - you then need to read all of the atoms to ensure there's no non-moneyed latinum mixed in and verify them. And, of course, you then need to prevent forgeries.
And is all this state intervention and enforcement really the (pre-Moogie) Ferengi?