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.
Identification of a TBHQ-Interfering Peak in Crude Canola Oil Using AOCS Official Method Ce 6-86 and its Chromatographic Resolution
