Pokémon Black Version and Pokémon White Version - Last item consumed
The last item consumed by a Pokémon is the last item that was consumed during the battle and was held by that Pokémon just before it was consumed (this includes Fling). Each Pokémon has a "last item consumed". The last item consumed for a Pokémon is retained even if the Pokémon leaves the battle and then enters the battle again in the same battle. An Air Balloon that "pops"; an item removed because of Bug Bite, Incinerate, Knock Off, or Pluck; and an item dropped with Item Drop are not considered the last item consumed, and they don’t reset the last item consumed.