Here's an article on Duty Free stores that was in yesterday's
Chronicle.
I'm amused by the instances of requiring people that do bring liquids on to taste them first.
As a recent piece at Slate said few of the potential chemicals for such bombs are immediately fatal and it is hard to believe that such a terrorist would have a problem taking a couple sips of slow-acting poisons. They are, after all, planning to die within the next few hours anyway.