This Poster shows how we compared the separation selectivity of 19 different HILIC Columns containing stationary phases including underivatized silica and hybrid particles, materials with neutral ligands such as cyano, amide, diol, pentahydroxy and urea, zwitterionic sorbents, and mixed-mode materials with amine functionalities. To evaluate the columns, we used a set of 77 small molecules, classified as cations, anions, or neutral based on their estimated charge under the separation conditions. Estimating the charge of the probes involved adjusting their dissociation constants for the acetonitrile content of the mobile phase and experimentally determining the pH of the acetonitrile-containing mobile phase. We visualized the results for the different columns using retention time correlation plots. The plots show that the selectivity differences strongly depended on ionic interactions. Comparisons of the neutral stationary phases (e.g., diol vs amide) showed more similar selectivity than did comparisons of neutral columns vs columns with cation or anion exchange activity (bare silica or amine columns, respectively). The zwitterionic columns did not behave as perfectly neutral. The correlation plots indicated that they exhibited either cation or anion exchange activity, although to a lesser degree than the silica and amine-containing stationary phases. These results are useful when selecting columns for method development.