The data used here are from a series of more than 12,000 retention measurements for 35 solutes on nine columns for multiple mobile phase compositions as reported by Kempen et al. . This resulted in 315 separate cases for testing the proposed re-parameterization and experimental design. Lists of the compounds and columns are provided in the supplementary material as Tables and. These data are freely available for interested researchers Further experimental details are provided in reference Retention data were collected for acetophenone, butyrophenone, 4,4'-dipyridyl, pnitrophenol and nortriptyline (obtained from Sigma Aldrich). Isocratic retention measurements were carried out for organic phase compositions that led to retention factors in the range of 1 to 20, at seven different organic compositions for each compound. Gradient measurements were obtained using the gradient design proposed here.