Superheated water: the ultimate green solvent for separation science

Normally, chromatographers regard water in reversed-phase chromatography as a largely inert diluent, which acts to weaken the “active organic modifier”, and as a “poor” solvent for most organic compounds, unless aided by ionisation. We rarely comment on its effect in separation science or consider if it has changeable properties that we can exploit. With a few exceptions, most liquid chromatography is carried out between 30 and 50°C, however, elevated temperature has a profound effect, both on the properties and separation power of water, that we are only just starting to exploit.