Identifying orthogonal and similar reversed phase liquid chromatography stationary phases using the system selectivity cube and the hydrophobic subtraction model

We have compared over 500 RPLC columns characterized by the hydrophobic subtraction model using the system selectivity cube (SSC). We have shown numerous differences in column selectivity even among columns in the same class (e.g., alkyl-silica, cyano, or embedded polar groups). We also illustrate the utility of our method for selecting alternative columns with different selectivities for problematic separations and for selecting orthogonal columns for use in two-dimensional separations. The system selectivity cube offers a visual way to easily compare many columns simultaneously and select those columns offering the desired selectivity.

► The system selectivity cube (SSC) guides RPLC column selection.
► The SSC can identify RPLC columns with similar and different selectivities.
► Column comparisons are shown within and between classes (e.g., C18, cyano, etc.).
► This application of the SSC is based on the Dolan–Snyder hydrophobic subtraction model (HSM).
► The HSM database includes over 500 commercial columns from a range of classes.