Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/1996
Publication Date: N/A
Technical Abstract: Phospholipids(PL's) are important cellular constituents of animals and plants. Physicochemical properties of cell membranes are dependent upon the composition of PL classes and subclasses. Quantification of PL compositions provide valuable information concerning the impact of genetic modifications on PL distributions in vegetable oils. Conventional reversed-phase HPLC separations of neutrally-charged PLs on octadecylsilica(ODS) often yield subcomponents with peak tailing or reduced detection sensitivity due to partial analyte adsorption on the ODS phase. We report a new reversed-phase HPLC-UV method for the analysis of the molecular species of phosphatidylcholine(PC) and phosphatidylethanolamine(PE) on several polymer columns. PC and PE samples derived from plants and animal tissues including those obtained by transphosphatidylization of egg PC were analyzed along with sphingomyelin samples. Mobile phases employed variable proportions of acetonitrile, methanol, and water. Separations of the PL molecular species were best achieved with a polyvinyl phase yielding peak characteristics similar to those observed in ion-pair HPLC of the neutral polar lipids on ODS with mobile phases containing counter-ion buffers. The polymer-phase HPLC results were also compared with those obtained with deactivated ODS columns. The new HPLC-UV method provides a convenient means to the analysis of molecular species of the title polar lipids utilizing simplified mobile phase systems without the use of buffer salts.