“…These t R predictors are based on quantitative structure‐retention relationships (QSRRs) that vary from very simple, which incorporate a single descriptor (Kern et al, ; Bade et al, ), to more complex, which use a large number of descriptors (Miller et al, ; Bade et al, ; Gago‐Ferrero et al, ; Munro et al, ; Barron and McEneff, ); however, all of these predictors are based on a single column, commonly a reversed phase (C 18 ) column. A direct‐mapping technique (PredRet) able to predict retention times across different chromatographic systems has also recently been developed (Stanstrup, Neumann, & Vrhovšek, ), but is limited to compounds having to be within the PredRet database. Although this area is rapidly advancing, the principal limitation is the use of a single column for most predictions, with further optimization needed for a truly transferable prediction technique.…”