Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of Vernonia galamensis oil

Matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) ma ss spectrometry (MS) has been used to identify eight triacylglycerols (TAG) in Vernonia galamensis oil (VO). The TAC include trivernolin, divernoloyls tearoylglycerol, divernoloyloleoylglycerol, divernoloyllinoleoylgylcerol, d ivernoloylpalmitoylglycerol, vernoloyllinoleoylstearoylglycerol, vernoloyll inoleoyloleoylglycerol, and vernoloyldilinoleoylglycerol. Samples for the M ALDI/TOF/MS analysis were prepared with alpha-cyano-4-hydroxycinnamic acid (matrix) in an acetonitrile/tetrahydrofuran solvent system. A mol ratio of matrix/VO (44:1) gave reproducible composite spectra, resulting in resoluti ons greater than 8,000 and signal-to-noise ratios of above 1000 for the mos t abundant molecular species. 1,3-Dioleoyl-2-stearoylglycerol and 1,2-diole oyl-3-patmitoylglycerol were used as calibration standards.