Quantitative analyses of polar components in frying oils by the iatroscan thin-layer chromatography-flame ionization detection technique.

Frying oils collected in restaurants were fractionated into a polar and a non-polar fraction by the Iatroscan thin-layer chromatography-flame ionization detection (TLC-FID) system on Chromarod S II using hexane-diethyl ether-acetic acid (97:3:1) as the solvent system. The FID responses for Iatroscan analyses of the polar and the non-polar fraction isolated from a frying oil by column chromatography on a 5% hydrated silicic acid were studied at Chromarod load levels ranging from 1 to 16 micrograms, relative to methyl heptadecanoate as the internal standard. The correction factors were relatively constant in the range 10-16 micrograms, but increased in the range 1-5 micrograms. The amount of polar material in ten commercial frying oil samples was quantitated by the Iatroscan TLC-FID technique. Good correlations were found between the results and data obtained by column chromatography and silica gel Sep-Pak cartridges.