Visual inspection of microscope images relying solely on RGB values has been sufficient for validating this methodology, including with non-specialist camera set-ups, but has limited the possibility to reason about reactivity in a quantitative manner. Hyperspectral imaging techniques, recently demonstrated in conjunction with microscopy, 17 can address this deficiency by enabling quantitative modelling of the effects of concentration and mixing. Moving beyond optical detection techniques, mass spectrometry provides access to much richer reactivity information. We envision that interfacing with mass spectrometers directly via release of analytes to MS as aerosols, using a gas-phase soft ionization technique such as atmospheric pressure chemical ionization (ACPI) to charge analyte molecules. There is also a growing set of techniques for MS imaging, e.g. desorption electrospray ionization (DESI) capable of yielding composition data for individual droplets.