Identification of glycerophospholipids in rapeseed, olive, almond, and sunflower oils by LC-MS and LC-MS-MS

HPLC employing a thermostatted Lichrospher 100 diol column was used to separate mixtures of glycerophospholipids of rapeseed, olive, almond, and sunflower oils. Elution was performed with a binary gradient of two mixed solvents A: hexane - isopropanol - acetic acid - triethylamine (82:17:1.0:0.08 v/v/v/v) and B: isopropanol - water - acetic acid - triethylamine (85:14:1.0:0.08 v/v/v/v). The LC effluent was directly introduced into the mass spectrometer through an electrospray capillary. Information about the fatty acid composition of each glycerophos pho lipid class was given by tandem mass spectrometry (MS-MS). These techniques permitted a rapid separation and identification of complex mixtures of glycerophospholipids. The relative abundance of each lipid class in each oil was also determined. The resulting glycerophospholipid signature may provide an efficient means of identifying oil origin and possible adulteration.