AbstractCommercial frying oil samples were fractionated by column chromatography on hydrated silicic acid according to the standardized DGF‐IUPAC‐AOAC method. The non‐polar fraction was isolated using a mixture of petroleum ether:diethyl ether (87:13), while the polar fraction was eluted by diethyl ether. These used frying oil samples were also fractionated using Sep‐Pak cartridges. The non‐polar fraction was eluted with 20 ml of a mixture of petroleum ether:diethyl ether (92:8), while the polar fraction was eluted with methanol.The purity of each fraction was studied by thin layer chromatography (TLC) and by the Iatroscan TLC/FID system using a mixture of hexane:tetrahydrofuran:acetic acid (97:3:1) as solvent system.The Sep‐Pak and the standardized methods gave similar results. This indicates that the state of degradation of a frying oil (detection of polar components) could be studied using Sep‐Pak cartridges, which is less time‐ and solvent‐consuming than column chromatography.