ARS | Publication request: A method of regiospecific analysis of triacylglycerols by ESI-MS3 and its use for olive oil analysis

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 27, 2007
Publication Date: May 18, 2008
Citation: Lin, J.T. 2008. A method of regiospecific analysis of triacylglycerols by ESI-MS3 and its use for olive oil analysis. AOCS Annual Meeting.

Interpretive Summary: A method of identification of the location of fatty acids chains on the glycerol backbone of triacylglycerols in vegetable oils and animal fats using mass spectrometry is reported here. The method can avoid contamination and thus a more accurate quantification can be obtained compared to that of the previous method. The method was used for olive oil analysis. The results showed that the saturated fatty acids were mostly located at the sn-1,3 positions of the glycerol backbone and unsaturated fatty acids were mostly located at the sn-2 position of the glycerol backbone.

Technical Abstract: A method of regiospecific analysis of triacylglycerols (TAG) in vegetable oils and animal fats is reported here using the electrospray ionization MS3 of TAG lithiated adducts. The fragment ions of the MS3 from the loss of fatty acids at the sn-2 position as alpha, Beta-unsaturated fatty acids were used for the regeospecific identification and quantification. The ratio of the regiospecific TAG, ABA and AAB, in a oil sample collected by HPLC can be determined by the ratio of the abundances of the fragment ions of [ABA + Li – ACOOH – B'CH=CHCOOH]+ and [AAB + Li – ACOOH – A'CH=CHCOOH]+. The method was used to analyze regiospecific TAG in extra virgin olive oil. The results showed that the saturated fatty acids, palmitic acid and stearic acid, were mostly located at the sn-1,3 positions and unsaturated fatty acids, oleic acid and linoleic acid, were mostly located at the sn-2 position.