| This study aimed to establish a novel robust method for simultaneous determinationof total fatty acid esters of4chloropropanols in edible oils, including fatty acid esters of3-monochloropropane-1,2-diol (3-MCPD esters),2-monochloropropane-1,3-diol (2-MCPDesters),1,3-dichloropropan-2-ol (1,3-DCP esters) and2,3-dichloropropan-1-ol (2,3-DCPesters). In this method, sodium methylate in methanol was used as the reagent for the estercleavage reaction of chloropropanols esters. The reaction products were extracted by asodium sulfate solution, and then purified by solid-supported liquid-liquid extraction (SLE)using diatomaceous earth (HydromatrixTM) as the sorbent. Finally, the extracts werederivatized with heptafluorobutyrylim idazole (HFBI) and analyzed by gaschromatography-mass spectrometry (GC-MS). Quantification was achieved usingdeuterated chloropropanols as their respective internal standards, including3-MCPD-d5,2-MCPD-d5,1,3-DCP-d5and2,3-DCP-d5. Good linearity was obtained within the range of0.025-2.000mg L-1with the correlation coefficients not less than0.999for all thechloropropanols esters. The limits of detection (LODs) of esters of3-MCPD,2-MCPD,1,3-DCP and2,3-DCP (calculated as corresponding chloropropanols) were30,30,100and30μg kg-1, respectively. The robust method validation data including calibration,LOD/LOQ, accuracy and repeatability and proficiency test results (Z-score:-0.5) of theofficial Food Analysis Performance Assessment Scheme (FAPAS) indicated that thepresent quantitative method could be successfully applied to the determination of totalchloropropanols esters in various edible oils.In this study, a method was established to3-chloropropane-1,2-diol esters in breadproducts by gas chromatography-mass spectrometry (GC-MS). The bakery products wereultrasonically extracted with hexane, followed by transesterification with sodiummethylate/methanol, and then passed through matrix solid-supported liquid-liquidextraction (SLE) for purification. After derivatization with heptafluoro butyrylimidazole(HFBI),3-MCPD was determined using GC-MS. The target compounds were separated ona HP-5capillary chromatographic column, and the tandem mass spectrograph was operatedin the selected ion-monitoring mode (SIM). There was an excellent linear correlationbetween the ratio of the3-MCPD and its internal standard and the mass (r=0.9999)between the ratio of the3-MCPD to the internal standard and the mass in the range of0.025-1.600mg/L of3-MCPD esters (calculated as3-MCPD). The limit of detection of3-MCPD esters in bread products was10μg/kg. The recoveries of the3-MCPD esters were in the range of82.9%~113.7%at the spike levels of40,100,160and240μg/kg intoblank bread products matrix, and the relative standard deviations (RSDs) were between2.1%and4.9%. The method is suitable for the determination of3-MCPD esters in breadproducts.A series of125refined edible oil samples purchased from market of Beijing ofChina were analyzed for fatty acid esters of chloropropanols (MCPDs esters) with gaschromatography-tandem mass spectrometry (GC-MS).3-MCPD esters were detected inoil samples representing91.2%, the highest incidence of MCPDs contamination occurredin edible oils, followed by2-MCPD esters (77.6%),2,3-DCP esters (13.7%) and1,3-DCPesters (0.8%). Total3-MCPD esters concentrations in all oil samples (n=125) rangedfrom non-detected to3.358mg kg-1, with a mean of0.832mg kg-1, and2-MCPD estersconcentration s were generally in range of <LOD and2.188mg kg-1(mean0.485mgkg-1), while lower levels of ND~0.340mg kg-1(mean0.018mg kg-1)and ND~0.077mgkg-1(mean0.001mg kg-1) for2,3-DCP esters and1,3-DCP esters, respectively. Theestimated daily intake of3-MCPD esters of Beijing people within a range of0~1.51μg/kg bw/d, is0~75.4%of JECFA-TDI of3-MCPD (2μg/kg bw per day). The averageEDI3-MCPD estersvia edible oil was0.374μg/kg bw/day, accounting for18.7%JECFA-TDIof3-MCPD. This is the first study to report levels of MCPDs esters in edible oils fromChina. |
PDF Full Text Request