title: Analysis of the oxidation products of cis- and trans-octadecenoate methyl esters by capillary gas chromatography-ion-trap mass spectrometry. I. Epoxide and dimeric compounds.
abstract: The oxidative behavior of methyl oleate (MeOl) and methyl elaidate (MeEl) was compared by hyphenated chromatographic techniques. MeOl and MeEl were separately oxidized (200 degrees C/30 min) and subjected to solid-phase extraction, in order to isolate the low polarity compounds. The two isomeric 9,10-epoxystearic methyl esters formed in both MeOl and MeEl at different threolerythro ratios (2.3 and 6.2%, respectively). The dimeric products produced in the thermoxidized MeOl and MeEl (1.4 and 1.6%, respectively), showed similar gas chromatographic characteristics and mass spectra, suggesting similar molecular structures and formation mechanisms. A positional and probably configurational mixture of symmetric and asymmetric dehydrodimers was detected, whereas the occurrence of MeEl or MeOl dimeric ethers is to be confirmed.
authors.affiliation: Department of Food Science, University of Bologna, Viale Fanin, 40, 40127 Bologna, Italy. glercker@agrsci.unibo.it
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lercker
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Rodriguez-Estrada
authors.forename: Matteo
authors.initials: M
authors.lastname: Bonoli
mesh_terms: D019281:Dimerization; D004852:Epoxy Compounds / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009829:Oleic Acids / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D004852:Epoxy Compounds; D004952:Esters; D009829:Oleic Acids