John's experience in trying to turn an idea into a successful invention is par for the course. It often takes ten minutes to think up a better widget and several years of head-butting to bring it to fruition.

The basic idea of distributing a selective adsorbant or absorbant at a fire scene and later analyzing mapped portions of the material is a good one.

There exist both mineral and organic materials which will preferentially incorporate hydrocarbons in their structures despite the presence of water.

I suggest that someone with ready access to GC/MS equipment continue with the evaluation of these materials where John left off.

Probably the best place to begin would be with materials which are currently used for liquid spill remediation in wet environments.