Abstract: In this study, a bottom-up method was established for the fast screening of eicosapentaenoic acid (EPA), docosapentenoic acid (DPA), and docosahexaenoic acid (DHA) acyl chain containing phospholipids. The oil extract from aquatic byproducts was injected using a syringe pump, and monitored under precursor ion scan (PreIS) mode with ?100 V declustering potential (DP) and ?40 V collision energy (CE) in the range of 350–1 150 Da. The product ions of m/z 301, 329 and 327 were used as the representative ions for EPA, DPA and DHA chains, respectively. The peaks of EPA, DPA and DHA were identified and quantified. The results showed that the aquatic byproducts contained many different types of EPA, DPA and DHA containing phospholipids. A total of 50 phospholipids of interest were identified, whose sn-1 positions were C16:0, C18:1 or C18:0 chains, including phosphatidylserine 20:5/22:6 and phosphatidylinositol 22:6/22:6, which were extremely unsaturated. Aquatic byproducts rich in EPA, DPA and DHA containing phospholipids therefore show great potential in the development of functional foods. The method was validated and found to be stable and precise as indicated by the relative standard deviations (RSDs) lower than 7.3%. In conclusion, this method is advantageous in fast screening of ω-3 fatty acyl chain containing phospholipids. Theoretically, this method is applicable to other biological samples as well, and can provide strong support for searching for new resources of ω-3 fatty acyl chain containing phospholipids.

Key words: direct injection, tandem mass spectrometry, phospholipids, aquatic byproducts, polyunsaturated fatty acyl chains