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 realized 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 analyzed by gas chromatography-mass spectrometry (GC-MS). Quantification is carried out by internal one-point-calibration. Six laboratories from four European countries participated in the trial and reported eight data sets for 10 test materials (mono- and diacylglycerides as well as polyglycerol polyricinoleates) that were analyzed as blind duplicates, giving a total of 20 samples. Result outliers were eliminated according to ISO 5725-2. At 2-MCPD levels above 0.02 mg/kg, 3-MCPD levels above 0.07 mg/kg and glycidol levels above 0.11 mg/kg repeatability (RSDr) ranged from 1.9% to 24.0%, reproducibility (RSDR) ranged from 6.7% to 29.2% and HorRat R values ranged from 0.4 to 1.6. 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.

Automated summary

An international robin round was conducted to validate a method for quantifying 2-MCPD, 3-MCPD, and glycidol in plant-based food emulsifiers. The modified AOCS Official Method Cd29b-13 was used for the analysis, with participants from six laboratories in four European countries. Results showed good repeatability and reproducibility for the quantification of these compounds in the tested food emulsifiers.