Current status of MCPD and Glycidol Analysis in Oils

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1 Current status of MCPD and Glycidol Analysis in Oils Mark W. Collison, Ph. D., Director, Analytical Chemistry Research Division Archer Daniels Midland Company and Chair of the Uniform Methods Committee

2 AOCS Indirect Methods Collaborative Methods were requested at the 2012 AOCS meeting ADM prepared test samples spiked with known amounts of 3-MCPD esters and glycidyl esters Three indirect methods were submitted AOCS also requested comparison with direct methods (Cd and other direct LCMS methods) 20 Laboratories participated in the collaborative study. 31 sets of data were submitted using indirect methods 8 sets of data were submitted using direct methods ARCHER DANIELS MIDLAND COMPANY 2

3 AOCS Indirect Method 1 12 labs 2- and 3-MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Edible Oils and Fats Based on Acid Transesterification Determines glycidol by pre-reaction with bromide 16 hour incubation at 40 C to convert MCPD esters to MCPD Determines both 2- and 3-MCPD ARCHER DANIELS MIDLAND COMPANY 3

4 AOCS Indirect Method 2 10 labs 2- and 3-MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Edible Oils and Fats Based on Cold (-22 C) Base Transesterification Corrects for artifacts by calculation of standards converted 16 hour incubation at -22 C to convert MCPD esters to MCPD Determines both 2- and 3-MCPD ARCHER DANIELS MIDLAND COMPANY 4

5 AOCS Indirect Method 3 9 labs 2- and 3-MCPD fatty acid esters and glycidyl fatty acid esters in edible oils and fats based on dilute base transesterification Determines glycidol by subtraction of the analysis in the presence and absence of chloride. Assumes that glycidol is the only precursor that produces artifacts Assumes that no chloride is present in the sample. Short incubation to convert MCPD esters to MCPD and glycidyl esters to MCPD ARCHER DANIELS MIDLAND COMPANY 5

6 Direct Methods: Cd labs (GE only) Joint AOCS/JOCS Official Method Cd Approved 2012 Glycidyl Fatty Acid Esters in Edible Oils DEFINITION This method is used for the determination of glycidyl (glycidol) fatty acid esters (GEs) in edible oils using double solid-phase extraction (SPE) and liquid chromatography mass spectrometry (LC-MS). SCOPE Applicable for the determination of glycidyl fatty acid esters (GEs) in commercial vegetable oils and fats. ARCHER DANIELS MIDLAND COMPANY 6

7 Direct Methods for MCPD Esters and Glycidyl Esters Each direct LCMS method was used in only one lab. TOF-MS method no pre-extraction LC/MS/MS with sample pre-extraction Wilm 2012 Yamazaki Tadmen ARCHER DANIELS MIDLAND COMPANY 7

8 Collaborative Results: Sample 1 Very high analyte concentrations Test sample for direct methods RBD Canola Oil spiked with 7 3-MCPD monoesters at ~7 ppm each, 28 3-MCPD diesters at 4-8 ppm each and 7 glycidyl esters at ~5 ppm each ARCHER DANIELS MIDLAND COMPANY 8

9 Collaborative Results: Sample 2 RBD Canola Oil spiked with 5 glycidyl esters at ~1.5 ppm each All indirect methods were reproducible for glycidol analysis ARCHER DANIELS MIDLAND COMPANY 9

10 Collaborative Results: Sample 3 RBD Canola Oil spiked with 15 3-MCPD diesters at 1 3 ppm each All indirect methods were acceptable for 3-MCPD analysis ARCHER DANIELS MIDLAND COMPANY 10

11 Collaborative Results: Sample 4 High level sample RBD Canola Oil spiked with 15 3-MCPD diesters at 4-8 ppm each and 5 glycidyl esters at ~5 ppm each All indirect methods were acceptable for both glycidol and MCPD analyses ARCHER DANIELS MIDLAND COMPANY 11

12 Collaborative Results: Sample 5 RBD Canola Blank used to make samples 1-4 Variable results between methods for both MCPD and glycidol at these low contaminant levels. ARCHER DANIELS MIDLAND COMPANY 12

13 Collaborative Results: Sample 6 Palm oil sample, not spiked. Low MCPD concentrations and moderate glycidol concentration. All indirect methods were acceptable ARCHER DANIELS MIDLAND COMPANY 13

14 Collaborative Results: Sample 7 Training sample. Palm oil (spiked levels from previous study) All indirect methods were acceptable and close to the direct methods ARCHER DANIELS MIDLAND COMPANY 14

15 Direct LCMS Methods for Glycidyl Esters Glycidol by LCMS analysis of glycidyl esters was good in most cases. Most LCMS methods for glycidol were in fair agreement with indirect methods and with the expected values for spiked samples. ARCHER DANIELS MIDLAND COMPANY 15

16 Direct LCMS Methods for MCPD Note: Direct LCMS methods did not resolve 2-MCPD from 3-MCPD. Samples were spiked with only 3-MCPD. Most LCMS methods for MCPD were in fair agreement with indirect methods and with the expected values for spiked samples. ARCHER DANIELS MIDLAND COMPANY 16

17 Summary All 3 of the indirect methods tested gave comparable results In general the direct methods agreed with the indirect methods. Methods, either direct or indirect, did not give reliable results if total MCPD concentrations or glycidol concentrations were below ~1 ppm. ARCHER DANIELS MIDLAND COMPANY 17