A simple and selective method was developed for the determination of enantiomeric glycidyl fatty acid esters (GE) in refined edible oils, which are undesirable trace contaminants formed during refining processes. For this purpose, chiral-phase high-performance liquid chromatography (HPLC) was performed with a column containing amylose tris(3,5-dimethylphenylcarbamate) as a chiral selector, using an acetonitrile/methanol mixture as the mobile phase, which gave clear enantiomer resolution of synthetic saturated and unsaturated GE racemates. This was followed by on-line atmospheric pressure chemical ionization mass spectrometry (APCI/MS) to obtain prominent protonated [M + H]
+ molecules, by which individual GE molecules could be identified and quantified. The quantification of GE enantiomers was performed in the selected ion monitoring (SIM) of [M + H]
+. This chiral-phase HPLC/APCI-MS-SIM method was standardized with synthetic GE racemates, and applied to the separation, identification and quantification of individual GE enantiomers in a commercial diacylglycerol (DAG)-rich oil produced originally from soybean oil and rapeseed oil. The results clearly showed that the DAG-rich oil contained almost equal amounts of
R- and
S-enantiomers of glycidyl palmitate (16 : 0-GE), stearate (18 : 0-GE), oleate (18 : 1-GE), linoleate (18 : 2-GE), and linolenate (18 : 3-GE), suggesting that both enantiomers would be formed from the corresponding almost racemic 1-monoacylglycerols. The most predominant GE was 18 : 2-GE, followed by 18 : 1-GE, which accounted for 107 and 25 μg g
−1, respectively, reflecting the fatty acid composition of the DAG oil.
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