A docosyl-terminated polyamine amphiphile-bonded stationary phase for multimodal separations in liquid chromatography

A convenient synthetic approach to a linear alkyl-polyamine amphiphilic chromatographic selector was proposed. Successive immobilization of the amphiphile onto silica gel afforded a multimodal stationary phase for high-performance liquid chromatography (HPLC). The as-prepared silica material was studied comparatively with a conventional octadecyl (C18) and an amide-embedded C18 stationary phase. The new uniform docosyl-triamine tandem was featured by an enhanced shape selectivity towards geometric isomers, and a low silanol activity towards alkaline solutes. The presence of multiple amino groups rendered the new adsorbent operable in different modes, such as hydrophilic interaction and ion-exchange modes. The satisfactory performance of the said stationary phase in separating different classes of analytes, including polycyclic aromatic hydrocarbons, flavonoids, tricyclic antidepressants, calcium channel blockers, aromatic acids, inorganic anions, nucleosides and estrogens, revealed its great potential and high adaptability for multipurpose LC utility.