Column chromatography and proton nuclear magnetic resonance (1H NMR) spectroscopy were used to set up a new analytical method to determine the composition of aliphatic alcohols and steroidal alcohols, namely 4-desmethylsterols, 4-monomethylsterols and 4,4’-dimethylsterols, of an olive oil sample. Aliphatic and steroidal alcohols are the minor components of the oil unsaponifiable fraction obtained generally by solvent extraction after oil alkaline hydrolysis with a potassium hydroxide solution. The new analytical method applied column chromatography to separate triacylglycerols from polar components ruling out any chemical reaction on the oil sample. Moreover, the use of 1HNMR spectroscopy , with a low resolution power but with a high sensitivity as compared to 13C NMR, enabled the selection of diagnostic resonances of the 1H spectrum of minor components isolated as a mixture from CC. Composition of aliphatic alcohols (only long chain alcohols), of -sitosterol (a 4-desmethylsterol), of citrostadienol (a 4-monomethylsterol), of 24-methylenecycloartanol and cycloartenol (4,4’-dimethylsterols), of triacylglycerols, and of 1,2- and 1,3-diacylglycerols, could be determined.
Loading....