A standard method for doing such an extraction from an aqueous medium is to use an Oasis MCX (mixed-mode cation exchanger) with the acidified sample. Amines will stick, everything else can be washed out with methanol, then the amines can be eluted with methanol that has been made alkaline with 1 or 2 % ammonia.
If olive oil is miscible with methanol, I would dilute the olive oil with methanol, acidify with something, maybe TFA, maybe just acetic acid, put this solution through a cartridge with the Oasis MCX ion-exchanger, wash with methanol and elute as above.
If olive oil is not miscible with methanol, I would try to extract the amines into the acidified methanol, and then do the same thing as described above. Methanol acidified as above as well.