Minimising solvent usage in high speed, high loading, and high resolution isocratic dynamic extraction

The development of the planetary-motion countercurrent chromatography machine into a high speed, high loading and high resolution dynamic extraction centrifuge has allowed the scale-up of the technique from analytical to pilot (kg/day). At this scale, solvent usage is a major consideration for both economical and environmental ("green") reasons. The analysis by gas chromatography of the composition of the two phases in solvent systems allows each layer to be made separately as required, minimising solvent wastage. Furthermore, as operation is generally isocratic, analysis of the recovered condensate from evaporated fractions allows the mobile phase to be easily reconstituted ready for re-use in the centrifuge. Such recycling further minimises solvent usage during preparative and pilot-scale separations.