Stationary-phase optimized selectivity in liquid chromatography (SOS-LC) for pharmaceutical analysis

Chromatographic method development for pharmaceutical analysis can benefit from in silico steered serial coupling of column segments containing different stationary phases of varying length. Contrary to column coupling through trial and error, in stationary-phase optimized selectivity (SOS)-based chromatography the retention of all solutes is predicted for all possible column combinations allowing a rational selection of the optimal column combination. The possibilities of the strategy now surpass the initial usage in isocratic high performance liquid chromatography (HPLC) on dedicated commercial column segments, and allow applications in gradient-, green-, preparative-, and in supercritical fluid chromatography (SFC) on conventional column hardware. Current possibilities, pharmaceutical applications, a downloadable algorithm, and weaknesses of the approach are discussed to allow broader implementation of this methodology in separation science