MASS SPECTROMETRY OF PHOSPHOLIPIDS. SOME APPLICATIONS OF DESORPTION CHEMICAL IONIZATION AND FAST ATOM BOMBARDMENT

Article abstract of DOI:10.1021/ja00330a035

Major diagnostic peaks in desorption chemical ionization (D/CI) and fast atom bombardment (FAB) mass spectra of various model synthetic phospholipids and related compounds are reported in conjunction with our ongoing research on marine phospholipids.Similarities and differences with some previous studies are presented.Commercially available or partially synthesized, saturated or unsaturated fatty acid containing phospholipids with different head groups such as choline, ethanolamine, mono- and dimethylethanolamine, serine, and glycerol were investigated.For identification purposes, 1,2-diacetylglycerol, 1,2-diacetyl-sn-glycero-3-phosphocholine, and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine-d9 were also prepared and their mass spectral behavior studied.In terms of diagnostically useful fragmentations ammonia proved to be superior to methane as reagent gas for chemical ionization.The use of deuterated ammonia shed light on the nature of several fragmentations.In most cases, both chemical ionization and fast atom bombardment techniques exhibited molecular ions and/or related peaks.Desorption chemical ionization with ammonia provided more information about fatty acyl moieties, while fast atom bombardment gave diagnostic peaks about various head groups.These two techniques thus offer comlementary information about the structures of intact phospholipids.