Liquid chromatography with particle-beam electron-impact mass spectrometryof diacylglycerol nicotinates

Several synthetic diacylglycerols and natural mixtures derived from soybean , egg yolk, and bovine liver phosphatidylcholines were examined in the form of nicotinate derivatives by liquid chromatography with particle-beam elec tron-impact mass spectrometry. High-performance liquid chromatography was c arried out in the reversed-phase mode with a base-deactivated octyl-/octade cylsilyl stationary phase. The nature (size and degree of unsaturation) of the acyl residues was readily determined from the mass spectra. Uniquely, t he positions of the double bonds could be deduced, although this became inc reasingly difficult as the degree of unsaturation of diacylglycerols contai ning mixed acyl residues increased. Reverse 1,2-diacylglycerol isomers coul d be distinguished by their mass spectra. (C) 1998 Published by Elsevier Sc ience Ireland Ltd. All rights reserved.