We are testing for surface elemental contamination in Plasma Sprayed Yttrium Oxide. The problem we are having is that our extraction solution is not beading up on the surface very well. Is there anyone that has experience doing this that can tell me the best way to prep the surface? The Yttria is sprayed on a small Aluminum coupon, and we need the extraction solution to bead up as much as possible. Right now we are having a lot of instances where our solution spreads across most of the coupon, which makes recovering the solution for analysis difficult. We also want to have more control over the extraction area.