[londons_explore]

I'm not sure any of today's mass spectrometers yet can match human smell in sensitivity, at least to some scents with larger more complex molecules.

[Beijinger]

"with larger more complex molecules."

What are "larger, more complex, molecules"? Without trolling, I think scent cuts off at a MW 330 or something.

[kolinko]

But it's not as good with distinguishing complex organic molecules one from another, no? I.e. between various proteins of a similar size.

[literalAardvark]

Mass spectrometry gives results that are a bit like the ingredient lists for food. Tells you precious little about the actual product.

[Beijinger]

You don't smell proteins.

[throwawaymaths]

Mass specs can detect down to the ten thousands? IIRC or so molecules.

[londons_explore]

But I don't think they can do that at the same time as having trillions of some other uninteresting molecule like water in them.

It's basically a dynamic range problem.

[sseagull]

Mass specs would have this problem, yes. That's why they are usually paired with chromatography of some sort (usually GC/MS or LC/MS). The GC or LC more or less reduce a mixture into components, which are fed into the mass spectrometer to analyze what those components are.

[throwawaymaths]

Yep the Ms that does this is tethered to chromatography first (sometimes even 2 or 3 different separation schemes in tandem)