> The most common way of analysing metabolite content is gas chromatography-mass spectrometry. This technique sorts molecules by their weight, producing a patte

> The most common way of analysing metabolite content is gas chromatography-mass spectrometry. This technique sorts molecules by their weight, producing a pattern of peaks that correspond to different substances. But the same weight can be shared by many molecules, so the results may be ambiguous. There's more to it than that. So basically you get a MS profile for each GC peak. But there are various ways to do MS. Some mainly give you masses of intact molecules, after ~gentle ionization. But some also give you masses of fragments, and that distinguishes among molecules with similar masses.