Fragmentation patterns of five types of phospholipids by ultra-high-performance liquid chromatography electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Abstract

Fragmentation patterns of phospholipids have been thoroughly investigated in previous studies. However, most studies only concentrate on these patterns for several phospholipids in single ion mode (positive or negative ion mode); this has not provided a systematic summarization for more phospholipids. Because phospholipidomics studies require high throughput screening of the target phospholipids, the necessity for rapid identification schemes for these compounds becomes obvious. Fragmentation patterns of five major types of phospholipids, including phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI) and sphingomyelins (SM), in different ion modes at several elevated collision energies (10–50 eV) have been studied by ultra-high-performance liquid chromatography electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC/ESI-Q-TOFMS). The different characteristic ions of phospholipids in ESI (±) modes, three possible patterns ([RCO]⁺, [RCOO⁻]⁻, and neutral ion R′CHCO) of fatty acyl chains in ESI (±) modes, and changes in the abundance ratios of the sn-1/sn-2 carboxylate anions of phospholipids at different collision energies, which can be used to quickly identify the positions of fatty acyl chains of phospholipids, were revealed. Fragmentation patterns of five major types of phospholipids were systematically summarized. This summary provides reference tools for the rapid identification of phospholipids and the opportunity to obtain complementary and more comprehensive results in future phospholipidomics studies.