Identification of glycerophospholipid molecular species of mussel (Mytilus edulis) lipids by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry

This study was carried out to identify the glycerophosphocholine (GPCho), glycerophosphoethanolamine (GPEtn) and glycerophosphoserine (GPSer) compositions in lipids extracted from mussels using Folch, Bligh-Dyer and methyl-tert-butyl ether (MTBE) methods by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). The molecular species of GPCho, GPEtn and GPSer were characterized according to the MS and MS/MS information. A semi-quantitative method using internal standard was established to compare the difference in glycerophospholipids (GP) between samples recovered with different methods. At least 212, 230 and 206 GP species were identified, respectively, from lipids recovered by Folch, Bligh-Dyer and MTBE methods. Most of the abundant GP species in mussels contained EPA and DHA. Some GP species with low content were not present in lipids recovered by the Folch and MTBE methods when compared with that recovered by the Bligh-Dyer method. However, for most GP species in lipids recovered by different methods, no quantitative differences existed.