Fellow Chemists, what would be a good way to measure the purity of Al alloys without damaging the Al?

Trying to think of some new methods for a work project. The Aluminum alloy pieces cannot be damaged as they are final product for the consumer companies. But the companies want us to have a new method of testing the pieces purity before shipping it out. The common practice is XRF analysis. To streamline that one idea we have is to get the hand held XRF machines (we currently use a stationary one thats as old as I am).

Another idea had been density. But the alloys are so small and VERY precise in content, nothing more than 2%, for example Aluminum-1%Si… that we’re not sure we could accurately measure density differences at such a small scale.

The last idea I had was measuring conductivity and/or resistivity. Not 100% sure on the process as I’ve yet to deduce or find a formula that will let us find out the resistivity of alloys in order to determine the conductivity.

Do you have any suggestions or new ideas? Also welcoming suggestions to do with those listed ideas. Again, the pieces CANNOT be damaged. We already run basic GC, GDMS, Spark Source, AA testing on the material prior to it being made into the pieces… We CANNOT run them on the finished pieces as it would destroy the product.