A series of refined edible oils derived from mixed seeds, peanuts, corn, sunflower and palm obtained from the local supermarket were analyzed for their content of 3-MCPD esters. A direct analytical method for the determination of 3-monochloropropane-1,2-diol esters (3-MCPD esters) was applied to investigate the major MCPD esters found in common edible oils; in particular seven types of monoesters and eleven types of diesters were detected. The limits of detection (LODs) for monoesters and diesters of 3-MCPD were in the range of 0.079-12.678 µg kg-1 and 0.033-18.610 µg kg-1 in edible oils, and the ranges of limits of quantitation (LOQs) were 0.979-38.035 µg kg-1 and 0.100-55 µg kg-1, respectively. The recoveries of 3-MCPD esters from oil samples were in the range of 80-100%, with RSD ranging between 1.9 and 11.8%. The concentration levels of total 3-MCPD diesters in vegetable oil samples were in the range from 0.106 up to 3.444 μg g-1 whereas total monoesters ranged from 0.005 up to 1.606 μg g-1.
Keywords: 3-MCPD esters; Refined oils; high resolution mass spectrometry.