VALIDATION OF A CHROMATOGRAPHIC METHOD FOR THE MCPD DETERMINATION IN VEGETABLE OILS

Today, esters of 3-monochloropropane-1,2-diol (3-MCPD-E) and glycidol (GE) remain one of the most pressing food safety issues, so a thorough study of their structure, formation mechanisms and control methods is an urgent issue. 3-MCPD and GE are fat-soluble toxic substances that can be formed in vegetable oils during their production and processing. Chloropropanols are by-products formed as a result of acid hydrolysis of glycerol lipids at elevated temperatures, during production or storage, and in the process of deodorization of edible oils. As a rule, 3-MCPD and GE are formed as a result of high-temperature exposure to fats, and they have carcinogenic, genotoxic, nephrotoxic and other types of negative effects on the human body. That is why their content is strictly regulated and must be controlled both in raw materials and in final products based on them. The direct determination of glycidol esters and fatty acid esters of 3-MCPD is performed by HPLC/MS/MS, but this method is difficult to use in practice due to the large number of components to be determined (84) and the lack of analytical standards. The most common indirect methods of control are when all esters of glycidol and 3-MCPD decompose to just glycidol and 3-monochloropropanediol, respectively. One of the earliest methods of determination adopted by the International Organization for Standardization is the ISO 18363-1:2015 method, which provided quantitative determination of 3-MCPD by alkaline decomposition of 3-MCPD esters and glycidol to 3-MCPD. The determination of glycidol esters in terms of glycidol was carried out by recalculating the difference in the quantitative results of two injections. The main disadvantage of this method is the inaccurate quantitative result for glycidol, since the method is based on the assumption that there are no other substances that react with inorganic chloride to form 3-MCPD. The following were the standardized methods ISO 18363-2:2018 and ISO 18363-3:2017. Both are already much more accurate than the previous one, but have a very long decomposition reaction time of more than 16 hours. This makes these methods very limited in their applicability to industries, but because of their direct quantification, they provide more accurate results for laboratories that issue certificates of analysis and are responsible for the quality of the values obtained.