Fully automated determination of 3-MCPD-, 2-MCPD-, and glycidol-esters in edible oils and fats based on ISO 18363-4 (Zwagerman/Overman) method

Fatty acid esters of 3—and 2-monochloropropanediol (3-MCPD-e, 2-MCPD-e) and glycidol (Gly-e) are process contaminants formed, for example, when edible oils and fats are refined. After ester cleavage during digestion in the human body, they pose a relevant health risk and, therefore, need to be determined in edible oils and fats and fat-containing food.
This study presents a fully automated methodology for determining fatty acid esters of 3-MCPD, 2-MCPD, and glycidol in edible oils and fats, adhering to the most recent ISO 18363-4 (Zwagerman/Overman Method). Using the GERSTEL MultiPurpose Sampler (MPS), manual steps are minimized to sample weighing, with all remaining sample preparation steps, and the injection into the GC-MS/MS system being automated. The method achieves quantification limits of 15 µg/kg for 3-MCPD, 5.7 µg/kg for 2-MCPD, and 44 µg/kg for glycidol, surpassing ISO standards. The inclusion of a backflush setup and optimized parameters ensures accuracy and precision (RSD < 5%) and extends the normal maintenance intervals necessary. Validation with reference samples confirmed trueness and compliance with EU regulatory limits, demonstrating the method's reliability and robustness for real-world applications in analyzing edible oils and fats for these contaminants.