Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of canola, castor and olive oils

A fast-drying sample preparation method, using α-cyano-4-hydroxycinnamic acid as a matrix in an acetonitrile/tetrahydrofuran solvent system, has been used to obtain the matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectra of commercial canola, castor and olive oils. The resulting spectra showed sodiated triacylglycerol molecules [M + Na]+. The canola oil contained at least eight triacylglycerols which were identified as: triolein, linoleoyldioleoylglycerol (OOL), dilinoleoyloleoylglycerol (OLL), trilinolein (LLL), dilinoleoyllinolenoylglycerol (LLLi), dioleoylpalmitoylglycerol (POO), linoleoyloleoylpalmitoylglycerol (POL) and dilinoleoylpalmitoylglycerol (PLL). The three brands of olive oil, Filippo Berio, Extra Virgin Pompeian and Progresso, were shown to contain triolein (OOO), OOL, OLL, POO and POL. The castor oil MALDI-TOF spectrum was uncomplicated, indicating the occurrence of triricinolein (RRR), diricinoleoylstearoylglycerol (RRS), diricinoleoyloleoylglycerol (RRO), diricinoleoyllinoleoylglycerol (RRL) and palmitoyldiricinoleoylglycerol (RRP).