SCOPE: 2- and 3-monochloropropanediol (2/3-MCPD) and glycidol are absorbed in the intestine after lipase-catalyzed hydrolysis of their fatty acid esters. METHODS AND RESULTS: In an exposure study with 12 non-smoking participants, the complete urinary excretion of the metabolite 2,3-dihydroxypropylmercapturic acid (DHPMA, UHPLC-MS/MS) and of 2/3-MCPD (GC-MS) was measured on four consecutive days before and after consumption of 50 g glycidyl ester-rich palm fat or 12 g 2/3-MCPD ester-rich hazelnut oil. After controlled exposure, urinary excretion rates of 2/3-MCPD per hour strongly increased, followed by a decrease with average half-lives of 5.8 h (2-MCPD) and 3.6 h (3-MCPD). After consumption of hazelnut oil, mean excretion rates were 14.3 % (2-MCPD) and 3.7 % (3-MCPD) of the study doses. The latter rate was significantly higher (4.6 %) after consumption of palm fat, indicating partial conversion (about 5 %) of glycidol to 3-MCPD under the acidic conditions in the stomach. The average daily "background" exposure was estimated to be 0.12 and 0.32 µg/kg bw for 2-MCPD and 3-MCPD, respectively. The relatively high and constant urinary excretion of DHPMA did not reflect the controlled exposure. CONCLUSION: Urinary excretion of 2- and 3-MCPD is suitable as biomarker for the external exposure to the respective fatty acid esters. This article is protected by copyright. All rights reserved.
Urinary Excretion of 2/3-Monochloropropanediol (2/3-MCPD) and 2,3-Dihydroxypropylmercapturic Acid (DHPMA) after a Single High dose of Fatty Acid Esters of 2/3-MCPD and Glycidol: A Controlled Exposure Study in Humans