Method Comparison and Application for the Determination of Free and Ester Bound 2,- 3-MCPD and Esterified Glycidol in Fishery Products
S Merkle1, H Karl2, J Kuhlmann3, J Fritsche1 
1University of Applied Sciences Hamburg, Hamburg, Germany
2Max Rubner-Institut, Department of Safety and Quality of Milk and Fish products, Hamburg, Germany 
3SGS Germany GmbH – Weidenbaumsweg 137 – 21035 Hamburg, Germany
 
3-Monochloropropane-1,2-diol (3-MCPD) is a food processing contaminant that might be formed by heating foods containing a chloride source and fat or during the wood smoking of fish and meat [1]. Investigations have shown that 3-MCPD in food also occurs as mono- or di-esters of fatty acids [2]. Further identified analogous compounds are glycidyl esters [3] and 2-monochloropropane-1,3-diol (2-MCPD) esters [4]. The IARC has classified 3-MCPD as a “possible human carcinogen (group 2B)” and glycidol as probably carcinogenic to humans [5,6]. 
Various analytical procedures for the determination of free 3-MCPD, 2-, 3-MCPD esters and glycidyl esters in foods have been published. But no official method exists for the determination in foods other than edible oils. 
Only limited data on the occurrence of these contaminants in fishery products is published and the EFSA is actually calling for additional occurrence data in foods [7].
In the presented study DGF standard methods C-VI 17(10) and C-VI 18(10) (AOCS method Cd 29c-13) and the “3 in 1” method (AOCS method Cd29b-13) were modified and validated in order to quantify ester-bound 2- and 3-MCPD and glycidyl esters in fishery products. The developed analytical methods were applied to quantify free and ester bound 2- and 3-MCPD and glycidyl esters in fishery products. 

[1]	Kuntzer, J., Weißhaar, R., The smoking process - a potent source of 3-chloropropane-1,2-diol (3-MCPD) in meat products. DLR. 2006, 102, 397-400.
[2] 	Zelinkova, Z., Svejkovska, B., Velisek, J., Dolezal, M., Fatty acid esters of 3-chloropropane-1,2-diol in edible oils. Food Addit. Contam.. 2006, 23, 1290-1298.
[3] 	Weisshaar, R., Perz, R., Fatty acid esters of glycidol in refined fats and oils. Eur. J. Lipid. Sci. Technol. 2010, 112, 158-165. 
[4]	Kuhlmann,. J., Determination of bound 2,3-epoxy-1-propanol (glycidol) and bound monochloropropanediol (MCPD) in refined oils. Eur. J. Lipid Sci. and Technol. 2011, 113, 335-344.
[5] 	IARC: 3-Monochloro-1,2-propanediol. Some Chemicals Present in Industrial and Consumer Products, Food and Drinking-water. IARC Monographs. 2012, 349-374.
[6] 	IARC: IARC monographs on the evaluation of carcinogenic risks to humans, some industrial chemicals, IARC Monographs. 2000, 469-486.
[7] 	EFSA (European Food Safety Authority) (2013). EFSA Journal 2013;11(9):3381.