Preparative LC and Preparative SFC: Two Complementary Techniques in the Fractionation of an Impurity from a Major Component

Abstract

Preparative liquid chromatography (LC) and preparative supercritical fluid chromatography (SFC) are compared for the fractionation of a minor component from a major one. The relative compositions of the binary mixtures of interest are 25:1 and 1:25. For each sample, a single column is used, and elution conditions are adjusted to obtain the same analytical resolution in both techniques. Comparison of purities and yields obtained from injection of the same column-overloading amount in both techniques shows that preparative LC and preparative SFC can be complementary. Fractionation is easier in preparative LC when the minor component is the first one to be eluted. Inversely, fractionation is easier in preparative SFC when the minor component is the second one to be eluted. Visualization of the elution profile of the minor component in each experiment shows that these behaviors result from peak interactions occurring under heavily overloaded conditions.