Optimization of a solid phase extraction and, sensitive HPLC-ELSD and HPLC-ESI-MS method for the determination of phospholipids in olive oil

Phospholipids belong to a polar lipid class of compounds and are particularly important as constituents of membrane of lipids in several food products. Some authors reported that some phospholipids found in vegetable oils display important biological activity and are useful in the prevention of certain diseases like arteriosclerosis. Nevertheless, phospholipids are poorly investigated as minor compounds in olive oil. In literature are present few articles focused on qualitative and quantitative analysis of phospholipids in virgin olive oil and, among them, an indirect determination of phospholipids by the phosphorous method that reported typical range values (21 to 124 mg/kg) of total phospholipids in veiled and filtered virgin olive oil and a study of individual phospholipids by NMR. Phospholipids’ isolation technique was essentially developed by liquid-liquid extraction (LLE). The aim of our work was to compare the effectiveness of LLE isolation methods with a direct separation and purification of olive oil's phospholipids with two different SPE sorbents (silica and diol). Furthermore, the extracts were analyzed by HPLC-ELSD and HPLC-ESI-TOF-MS to gain basic information useful for a possible identification of single components. To this aim a new separation method was established using an hydrophilic core shell liquid chromatography column.