Impact of column and stationary phase properties on the productivity in chiral preparative LC.

By generating 1500 random chiral separation systems, assuming two-site Langmuir interactions, we investigated numerically how the maximal productivity (PR,max ) was affected by changes in stationary phase adsorption properties. The relative change in PR,max , when one adsorption property changed 10%, was determined for each system and for each studied parameter the corresponding productivity change distribution of the systems was analyzed. We could conclude that there is no reason to have columns with more than 500 theoretical plates and larger selectivity than 3. More specifically, we found that changes in selectivity have a major impact on PR,max if it is below ∼2 and, interestingly, increasing selectivity when it is above ∼3 decreases PR,max . Increase in relative saturation capacity will have a major impact on PR,max if it is below ∼40%, but only modest above this percent. Increasing total monolayer saturation capacity, or decreasing the first eluting enantiomer's retention factor, will have a modest effect on PR,max and increased efficiency will have almost no effect at all on PR,max unless it is below ∼500 theoretical plates. Finally, we showed that chiral columns with superior analytic performance might have inferior preparative performance, or vice versa. It is, therefore, not possible to assess columns based on their analytical performance alone.