Rapid prediction and optimization of concentration conditions for preparative fractions by solid-phase extraction

SPE is an effective tool for concentrating preparative fractions isolated from a complex sample. To guarantee high efficiency and recovery of concentration, the concentration conditions could be optimized by predicting the breakthrough volume (V-B). In this study, a method of predicting V-B of unknown compounds in preparative fractions at any isocratic mobile phase composition with the analytical retention parameters a and c is described. The a and c values and the relationship between half peak width (W-1/2) and retention time of a model analyte were measured using the analytical elution mode on an SPE column, and the V-B and retention volume (V-R) predicted with the a and c values were validated with breakthrough experiments. However, it is impossible to measure the a and c values of multiple compounds in a complex system directly on an SPE column with a low number of theoretical plates. The correlation of the a and, c values between the SPE and analytical columns was developed so that the analytical data could be transferred to the SPE column. With the calculated a and c values, we could optimize the concentration conditions on the basis of the predicted V-B and the volume of the preparative fraction