MathFox is correct. All duty-free booze (and other liquids that do not meet the standard 100ml/one-litre bag rule) that were not purchased and sealed at an EU airport will be taken from you at the gate in AMS.
Some airlines will allow you to check in your duty-free purchases at the gate as additional checked baggage, but most won't (presumably because of the logistical problems of doing so).
Incidentally, because security checks at AMS take place at the gate, you will also be unable to take on board any bottles of water or other soft drinks you purchase in the airport shops.