Pour acetone over the amphetamines until it is well covered with acetone. If you need a ml amount; 10-15ml per gram is plenty. You can use as much as is convenient, just try to make it so you're not wasting too much acetone. Make sure the edge of your tray/dish is high enough so you can still stir it without spilling anything.
Stir, make sure all the amphetamines are spread out and that there's no "lumps" left. The solution in your plate will be cloudy.
Give it a minute to settle.
Now take your syringe, and using the qtip as a filter, draw up the acetone with your syringe. Depending on the size of your syringe this can take a few times but shouldn't be too hard.
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