DETERMINATION OF LIPID ESTER OZONIDES AND CORE ALDEHYDES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ONLINE MASS-SPECTROMETRY

Unsaturated triacylglycerols (TG) and choline (PC) and ethanolamine (P E) phosphatides of known structure were subjected to ozonization and r eduction with triphenylphosphine to yield the corresponding lipid este r core aldehydes. Mono- and di-C-9 aldehyde palmitoylglycerols were pr epared from oleoyldipalmitoyl and oleoyllinoleoylpalmitoyl glycerols, respectively, while egg yolk PC and PE provided the mono-C-5 and mono- C-9 aldehydes of palmitoyl-and stearoyl glycerophospholipids. The alde hydes were isolated in the free form and as the dinitrophenylhydrazone (DNPH) derivatives by thin-layer chromatography (TLC). The intermedia te ozonides, free aldehydes and hydrazones were identified by reversed phase high performance liquid chromatography (HPLC) with on-line nega tive ion thermospray and normal phase HPLC with on-line positive ion e lectrospray mass spectrometry (LC-MS). The synthetic aldehydes were us ed as carriers during isolation from natural sources and as reference compounds in quantitative analyses