Bidirectional Conversion Between 3-Monochloro-1,2-propanediol and Glycidol in Course of the Procedure of DGF Standard Methods
- 361 Downloads
NMR observation revealed that bidirectional conversion occurred between 3-monochloropropane-1,2-diol (3-MCPD) and glycidol in the course of the analytical procedure of DFG standard method C-III 18 (09), option A; 3-MCPD was partly converted to glycidol at the transesterification step, and glycidol was converted partly to 3-MCPD at the derivatization step conducted at 80 °C under acidic condition in the presence of NaCl. Based on the proton numbers observed by 1H NMR, the degrees of the conversion were estimated to be 37 and >70%, respectively. In addition, epoxide ring-opening of glycidol and its esters was found to be ca. 90% by the acid treatment described in the method, option B. Thus, it was concluded that the standard method, option A, did not correctly give the combined amount of 3-MCPD esters and glycidyl esters in oils containing glycidyl esters, and the difference of the values obtained by options A and B did not correspond to the amount of glycidyl esters, either. In addition, derivatives of 3-MCPD with phenylboronic acid were not observed by NMR at the derivatization step, although they were detected by GC-MS in the organic phase at the following extraction step.
Keywords3-Monochloropropane-1,2-diol (3-MCPD) DFG standard method Glycidol Glycidyl ester NaCl
- 1.Food Advisory Committee (2000) Genotoxicity of 3-monochloropropane-1,2-diol, FdAC/Contaminants/48. Paper for Discussion. UK Food Standards Agency, London. http://archive.food.gov.uk/pdf_files/papers/fac_48.pdf. Accessed Oct 2010
- 2.FAO/WHO (2001) Joint FAO/WHO Expert Committee on Food Additives (JECFA) Fifty-Seventh Meeting, Rome, 2001, Summary and conclusions (Rome: Food and Agriculture Organization of the United Nations/World Health Organization). http://www.vegsource.com/articles/carrageenan/JECFA_2001_Carrageenan_Report.pdf. Accessed Oct 2010
- 3.(2009) Ester-bound 3-chloropropane-1,2-diol (3-MCPD esters) and glycidol (glycidol esters). Deutsche Gesellschaft fuer Fettwissenschaft: DGF Standard Methods (14. Supplement) C-III 18 Google Scholar
- 9.Kaze N, Sato H, Yamamoto H, Watanabe Y Improvement of accuracy in quantification of 3-monochloropropane-1,2-diol and its esters by DGF standard methods C-III 18 (in submission)Google Scholar