Turning on the Heat in Liquid Chromatography - Tony Edge & Luisa Pereira

The use of temperature within liquid chromatography (LC) has traditionally been limited to isothermal studies up to 50° or 60°C. However, this does not realise the full potential that temperature can have within a liquid chromatographic system. In particular the ability to run with thermal gradients [1,2] or to run green LC [3,4], where there is no organic solvent used, is something that is not considered as routine within the liquid chromatography community.

The advent of ultra-high pressure liquid chromatography (UHPLC) has meant that chromatographers are becoming more aware of the extremes of chromatography, and the benefits that this can have in terms of the separations either due to efficiency gains or reduction in sample analysis times. The advent of the new phases has also led coincidentally to robustness in the column performance at elevated temperature allowing for more extreme chromatography to be tried. The advantages of this form of extreme chromatography are many-fold e.g. a reduction in viscosity leads naturally to a reduction in the operating pressure, allowing for much higher flow rates and thus reducing analysis times. It also leads to substantial changes in selectivity which can benefit the chromatographer. Interestingly the use of HypercarbTM, which is an ideally suited stationary phase for these extreme conditions, is seeing an increase in the number of applications [5,6].