New method for direct determination of glycidyl esters using LC-MS
By Dr. Claudia Schulz, Dr. Susanne Rathjen and Sabrina Ment, Eurofins WEJ Contaminants GmbH, Germany
Edible fats and oils are subject to processing in order to improve quality, stability, and safety. Although this procedure removes a very large portion of impurities from the oil, the formation of process contaminants can result in a significant health risk. Along with monochloropropanediol (3-MCPD) esters, glycidyl fatty acid esters are of concern as they may occur in refined edible fats and oils and corresponding finished food products, including infant formula.
The toxicological relevance of glycidyl esters is just as unclear as the question of their hydrolysis within the human digestive tract. Glycidol itself – the epoxide of glycerol - has carcinogenic and mutagenic features. The German Federal Institute for Risk Assessment (BfR) presently assumes that all the glycidol is released for glycidol esters in the digestive tract. Thus, it is important to minimise glycidyl esters in food.
The analysis of the various 3-MCPD mono- and diesters and glycidyl esters is extremely complex with a couple of direct and indirect methods in existence. Certain indirect methods using GC-MS allow the determination of glycidyl esters by transforming them to 3-MCPD which is then quantified, however, this results in a larger uncertainty. Direct determinations of single 3-MCPD esters and glycidyl esters require a range of reference standards which – in case of 3-MCPD esters – currently are not commercially available.
In order to remain aware of the latest analytical developments Eurofins WEJ Contaminants is an active member of various analytical working groups, e.g. the German BfR, the German Association for the Science and Technology of Lipids (DGF) and the American Oil Chemists’ Society (AOCS).
Eurofins now offers a direct method for the quantification of the seven most relevant and commercially available glycidyl esters (C12 – C18) using two consecutive solid phase extraction steps followed by LC-MS based on a recent AOCS draft.