Analysis of molecular species of phospholipids by field desorption mass spectrometry

Various glycerophospholipids including their trimethylsilyl and t-butyldimethylsilyl derivatives and cerebroside were analysed by field desorption mass spectrometry with a silicon emitter. Choline glycerophospholipids with diacyl residues and also alk-1'-enyl and acyl residues gave the readily interpretable field desorption mass spectra in which a sodium cluster ion [M+NA]+ was a base peak. As to phosphatidylethanolamine and cerebroside, a protonated molecular ion [M+H+]+ was a base peak. The TMS and TBDMS derivatives gave a molecular ion [M]+. The field desorption analysis of natural phospholipids from myelin was carried out in comparison with the gas chromatographic mass spectrometric analysis.