Thanks. I’ve got a few ideas I want to try out. I want to see what @taricha has up his sleeve first, but I plan on writing up a formal protocol and sharing it here for comments before executing the study. I’d like to look at a few different angles in one comprehensive study with well designed controls and appropriate orthogonal methods. I am a pharmaceutical formulation chemist professionally, so hopefully I can contribute something to the community this way.All the ammonia ISE instructions I've seen involve the addition of a pH adjuster to raise pH and convert all ammonium to ammonia. In theory, you could skip the pH adjuster and test free/unbound-to-Prime ammonia but I'm not sure it'd actually work.
I’m working on finding some non-GMP instrumentation at work and might even be able to get a little fancy with FT-IR, ITC, MS, and even NMR (probably a long shot).