Enantioseparation through supercritical fluid simulated moving bed (SF-SMB) chromatography

In this work, the first enantioseparation in a SF-SMB unit, i.e., a simulat ed moving bed (SMB) operated under supercritical conditions, is reported. C omplete separation of the two enantiomers of tetralol was achieved both in the pressure-gradient mode (where a pressure gradient is imposed along the four sections of the unit) and in the isocratic mode (where the pressure is kept constant). However, an almost 3-fold increase in productivity could b e achieved in the pressure-gradient rather than the isocratic mode. The obt ained results are explained and rationalized using recently developed desig n criteria for SMBs, the so-called "triangle theory", which have been prope rly extended to allow for different pressure values in the different sectio ns of the unit.