..recently I've found an old AGP column being in a drawer for many years. I am wondering if it still works? At least it was a 1000 $ investment.
3 questions:
- does anyone know anything about the lifespan of this kind of column?
- is there a sensitive procedure to check the performance (may be even for minor
changes)?
- is there a chance to reactivate the column and what is the best way for
storing it?

Re Old columns: It all depends what you want to do with a column. If you just want to do a particular analysis that you will never ever have to reproduce, you can develop the method on any old column, as long as it shows some of the desired activity. If you want to develop a method that you or somebody else needs to reproduce in the future, I would not even think twice and throw the column away. You risk all your time that you'll spend on the development of the method, and the chances are high that a brand-new column won't do the same job as the ancient one.

Your answer is correct. Thanks.
...anyway it doesn't answer the questions...

You should be able to get the information re shelf
life,storage and regeneration by calling vendor
technical support. Two AGP vendors, which come to
mind, are Astec and Regis. For column evaluation
they can also provide the test sample (either what
it is or the sample itself). This sample is sent
with the column at the time of purchase.