Systematic Study of Feed Temperature Control to High Performance Liquid Chromatography

Summary

Some system factors like poor packing, distribution system and viscous heat dissipation may result in the core of a solute concentration band goes faster, forming a parabolic concentration band and reducing column efficiency. Feed temperature control method, which is to appropriately control eluent at the column inlet at a temperature lower than the wall temperature, can modify the band shape and counteract such negative effects. Using Computational Fluid Dynamics (CFD) software FLUENT, the present work investigated the effect of a variety of system factors on the temperature distribution in a chromatographic column and the optimal temperature difference between the inlet and the column wall in feed temperature control, ΔT _opt . It was found that the factors affecting flow distribution have no significant effect on temperature distribution but significantly affect ΔT _opt . The factors strongly related to temperature distribution might not interfere with ΔT _opt . The reason is that the principle of feed temperature control is to reshape the solute concentration band, which depends on flow distribution. This work also found that for a given column and a given eluent, ΔT _opt was independent of the Reynolds No and Peclet No derived from component balance ΔT _opt depends on Peclet No derived from energy balance, but the correlation between them is uncertain due to the unclear effect of λ _eff on ΔT _opt .