Estimating Chromatographic Enantioselectivity (α) from Gradient Enantioselective Chromatography Data

Calculation of chromatographic enantioselectivity (alpha) is critically important in enantioselective chromatographic method development studies. The fact that a can only be calculated from isocratic elution conditions, whereas gradient elution conditions are predominantly used in method development screening, presents some problems for the use of a as a scoring indicator for automated, intelligent enantioselective chromatography method development systems. In this study, an empirical algorithm was developed to estimate a at isocratic conditions based upon information collected from a gradient elution. The algorithm was validated for SFC applications and has been shown to accurately predict enantioselectivity for a wide variety of racemic test analytes eluted on different chiral column and mobile phase conditions. Chirality 23:128-132, 2011. (C) 2010 Wiley-Liss, Inc.