> a histogram of all the chemicals that are present, that would probably be doable if not already done.

I'm no olfactory biochemist, but that sounds like science-fiction to me. The, er, reference implementation we're talking about is advanced nanotechnology we don't fully understand.

While we can do stuff like mass-spectrography, that involves destroying complex chemicals and converting them to smaller fragments we can tally, and then guessing at possible configurations they might have originally had.

If someone had a device that could simply tell you the exact chemical formulas of all molecules of any kind in a sample, it would be used everywhere and they would be very rich.

You are right that such device does not exist, but in theory you could combine many analytical techniques to a single black box that could analyze practically all of molecules and particles in the air or even in more complicated samples. It would contain at least some sort of chromatography, nmr, mass spectrometer, infrared spectrometer and various special analytical techniques for some compounds. Also some kind of sample preparation system would be needed.

This would be a very large machine and you would need to provide a sample to it in a test tube or similar manner. Automated blood analyzers in hospitals are maybe the closest thing to a such device.