SIELC Primesep HPLC columns are designed for mixed-mode separations and capable of separating a tremendous range of compounds by different separation modes based only on the mobile phase selection. With an embedded ion-pairing group, the columns require no ion-pairing reagents in the mobile phase to retain and separate ionizable polar compounds. These columns have shown to efficiently separate organic and inorganic ions in ion-exchange and ion-exclusion modes. The columns can be used to provide efficient separation in normal phase, reverse phase, and polar organic modes. Different modes of separation offer different column selectivity.