Collaborative Study for the Quantification of Total Contents of 2- and 3-Monochloropropanediol and Glycidol in Food Emulsifiers by GC-MS

An international robin round was carried out to validate a method for the quantification of 2-monochloropropane-1,3-diol (2-MCPD), 3-monochloropropane-1,2-diol (3-MCPD) and 2,3-epoxy-1-propanol (Glycidol) being present as fatty acid esters in plant-based food emulsifiers. The evaluated method was a modification of the American Oil Chemist´s Society (AOCS) Official Method Cd29b-13. Briefly, this method consists from parallel analysis of two sample aliquots that are spiked with different sets of internal standards. Mild alkaline interesterification overnight in the freezer releases the core analytes. Reaction stop and glycidol conversion into monobromopropanediol (MBPD) is realised by addition of acidified sodium bromide solution. Subsequently, matrix removal and analyte extraction are achieved by two liquid/liquid (l/l) extraction steps. After derivatisation with phenylboronic acid (PBA) the final extracts are analysed by gas chromatography-mass spectrometry (GC-MS). Quantification is carried out by internal one-point-calibration. 6 laboratories from 4 European countries participated in the trial and reported 8 data sets for 10 test materials (mono- and diacylglycerides as well as polyglycerol polyricinoleates) that were analysed as blind duplicates, giving a total of 20 samples. Result outliers were eliminated according to accepted standards. At 2-MCPD levels above 0.02 mg/kg, 3-MCPD levels above 0.06 mg/kg and glycidol levels above 0.22 mg/kg repeatability (RSDr) ranged from 1.5 % to 24.9 %, reproducibility (RSDR) ranged from 7.8 % to 29.0 % and HORRATR-values ranged from 0.5 to 1.7. The tested method showed to be suitable for the determination of 2-MCPD, 3-MCPD and glycidol in food emulsifiers consisting from mono- and diacylglycerides as well as polyglycerol polyricinoleates.

Review of Methods for Preparation and Gas Chromatographic Separation of trans and cis Reference Fatty Acids

In recent years, several countries have implemented new regulations regarding the limitation or labeling of the trans fatty acid (TFA) content of foods and dietary supplements. GC methods for fatty acid (FA) analysis have been updated by improving the separation of TFAs from other FAs, especially trans- and cis-18:1, and by focusing more attention on the FAs contained in fats and oils in lower amounts. FA analysis is affected by the limited availability of reference materials. Identifications are frequently made simply by comparison with separations reported in the literature. This report describes the preparation of mixtures containing fatty acid methyl esters (FAMEs) that are not available as reference materials. These mixtures can be used for FAME identifications. The prepared mixtures are analyzed under the experimental conditions of the American Oil Chemists' Society (AOCS) Official Method Ce 1h-05 and AOCS Recommended Practice Ce 1j-07.