CHARACTERIZATION OF MODEL TRIACYLGLYCEROL (TRIOLEIN, TRILINOLEIN AND TRILINOLENIN) AUTOXIDATION PRODUCTS VIA HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY COUPLED WITH ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION MASS-SPECTROMETRY
We. Neff et Wc. Byrdwell, CHARACTERIZATION OF MODEL TRIACYLGLYCEROL (TRIOLEIN, TRILINOLEIN AND TRILINOLENIN) AUTOXIDATION PRODUCTS VIA HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY COUPLED WITH ATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION MASS-SPECTROMETRY, Journal of chromatography, 818(2), 1998, pp. 169-186
Citations number
24
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
Oxidation products from the autoxidation of three triacylglycerol stan
dards have been analyzed using reversed-phase high-performance liquid
chromatography (RP-HPLC) coupled to mass spectrometry via an atmospher
ic pressure chemical ionization (APCI) source. Triolein, trilinolein a
nd trilinolenin were autoxidized in the dark at 50-60 degrees C until
the oxidation products represented approximately 30% of the starting m
aterial. These oxidation product mixtures were then analyzed using RP-
HPLC-APCI-MS. Several classes of oxidation products were directly dete
cted and identified. Monohydroperoxides were present in the largest am
ounts in the oxidation products mixtures. The hydroperoxides were foun
d to provide several structurally useful fragments: epoxide intermedia
tes were formed which then underwent further fragmentation, and other
fragments were formed from concerted loss of the hydroperoxide group t
o form a site of unsaturation. Fragments formed by intra-annular cleav
age of epoxide intermediates allowed identification of several hydrope
roxide isomers. Bishydroperoxides were observed which underwent simila
r fragmentation pathways. Mono- and diepoxides were also formed by the
autoxidation reaction. Two classes of epoxides were observed: those i
n which an epoxide formed in place of an existing double bond, and tho
se in which an epoxide formed away from a double bond. Two distinct fr
agmentation mechanisms were observed for epoxides which were not forme
d across a double bond. Other oxidation products which were observed i
ncluded hydroxy trilinolenin, epidioxy trilinolenin and hydroperoxy, e
pidioxy trilinolenin. (C) 1998 Published by Elsevier Science B.V. All
rights reserved.