A Decade of Advancing the Direct Analysis of MCPD and Glycidyl Esters at the U.S. FDA: Insights and Future Directions

Abstract: Fatty acid esters of 3-monochloro-1,2-propanediol (3-MCPD), 2-monochloro-1,3-propanediol (2-MCPD), and glycidol are process-induced chemical contaminants found in a variety of edible oils and food products containing these oils. Studies have shown these contaminants may be carcinogenic and/or genotoxic, making their presence in foodstuffs a potential health concern. Over the last two decades, numerous analytical methods for the quantitation of these contaminants have been developed, and these methods can generally be categorized as “indirect” or “direct” techniques. Indirect techniques involve transesterification, or conversion, of the individual esters to their corresponding free forms (3-MCPD, 2-MCPD, or glycidol), which are then quantified using gas chromatography-mass spectrometry (GC-MS) methods. The direct techniques, on the other hand, involve the detection of the individual intact esters by liquid chromatography-mass spectrometry (LC-MS) methods followed by a mathematical conversion of the ester concentrations to 3-MCPD, 2-MCPD, and glycidol equivalents.

Although indirect techniques are typically used for routine/regulatory testing purposes, direct methods for MCPD and glycidyl esters analysis demonstrate efficacy and utility for a number of research-related objectives. In particular, our laboratory at the U.S. FDA has developed and utilized direct detection techniques for MCPD and glycidyl esters analyses for more than 10 years. This presentation will discuss the fundamentals of direct detection as well as the challenges related to performing this type of analysis. In addition, several examples of notable findings and key insights using direct detection will be presented, along with potential future applications for direct detection methodology.