Comparative analysis of different plant oils by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

Different vegetable oil samples (almond, avocado, corngerm, grapeseed, linseed, olive, peanut, pumpkin seed, soybean, sunflower, walnut, wheatgerm) were analyzed using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. A gradient elution technique was applied using acetone-acetonitrile eluent systems on an ODS column (Purospher, RP-18e, 125x4 mm, 5 mum). Identification of triacylglycerols (TAGs) was based on the pseudomolecular ion [M+1](+) and the diacylglycerol fragments. The positional isomers of triacylglycerol were identified from the relative intensities of the [M-RCO2](+) fragments. Linear discriminant analysis (LDA) as a common multivariate mathematical-statistical calculation was successfully used to distinguish the oils based on their TAG composition. LDA showed that 97.6% of the samples were classified correctly. (C) 2002 Elsevier Science B.V. All rights reserved.