Nepetalactone is the active ingredient in catnip.* Today we are going to isolate nepetalactone in its pure form through a steam distillation. The distilled liquid will be extracted with an organic solvent (toluene), refined, then evaporated to give the final product.
Now I know what you're thinking: is it safe for cats to be around such a concentrated extract of catnip? Hell yes! Within reason. And we're all reasonable people. Pure nepetalactone has been studied on cats extensively. In fact, "catnip oil" that is available from botanical stores is essentially just nepetalactone, and it is widely used in homeopathic medicine. More details later.
- Note: pure nepetalactone will not enable you to create a cat army.
Step 1: Crash course in steam distillation
This is particularly useful for extracting plant matter, where the steam serves double duty, breaking open cell walls and releasing volatile oils like nepetalactone. A standard apparatus that you would use in a chemistry lab is shown in the first picture below. Of course, we'll be doing this at home without access to fancy science gadgets.
For this catnip extraction, I've constructed a much simplified apparatus shown in the second picture. The catnip and water goes in the bottom of a big pot, with a cup placed on top. The lid is really the key component here; by simply turning the lid of the pot upside down, the vapors will condense and drip down from the center, collecting in the cup below. By filling the top of the lid with ice water, the vapors are condensed very efficiently.