So I know I need a analytic potion to gather each sample but how do you get another potion? I've hailed Drent and he doesnt hand one out. I'm thinking you have to complete the quest the play session you get it and that logging partway through maybe messed this up for me??
Even though the quest probably updates after you "create" the potion, the Allakhazam write-up says you need to kill a total of 9 beetles and 9 snakes to get the necessary 9 potions. I also wanted to make sure you know this task is not needed for progression or the partisan achievement.
Kill a snake and a beetle and it will create another potion, then kill one on the list, rince and repeat. Or you can kill a bunch of snakes and beetles and more will be created. Need 1 of each for each potion.