AOAC 2018 Methods

AOAC Official Method 2018.03 2- and 3-MCPD, 2- and 3-MCPD Esters, and Glycidyl Esters (GE) in Infant and Adult/Pediatric Nutritional Formula Gas Chromatography-Mass Spectrometry AOAC First Action 2018

(Applicable for determination of 2- and 3-MCPD esters and Glycidyl esters in Infant/nutritional formula in the 4-2000 µg/kg range for powder formula and in the 0.7-333 µg/kg range for liquid formula. Method is also applicable for determination of 2.5-750 µg/kg free 2-MCPD and 3-MCPD in formula.) Caution : Refer to Material Safety Data Sheets prior to use of chemicals. Use appropriate personal protective equipment when performing testing. Because of the use of chemical solvents, acids and reagents, sample preparation should be conducted under a fume hood and appropriate safety precautions should be taken. MCPD and glycidol are released from their esterified forms during digestion and have been classified as carcinogenic to humans (group 2B and 2A, respectively). A. Principle Fat from Infant or Nutritional formula is first extracted by a liquid-liquid extraction using ethyl acetate, modified from (1). Depending on mono- and diglyceride content, an additional cleanup by SPE is performed (2). Oil samples and fat extracted from formula are then analyzed for bound MCPD and Glycidyl esters, modified from (3). Glycidyl esters are converted to 3-monobromopropanediol (3- MBPD) monoesters in an acid solution containing a bromide salt. 3-MBPD esters, together with 2- and 3-MCPD esters, are then converted into the free (non-esterified) form in an acid methanolic solution. The fatty acid methyl esters generated during the reaction are extracted from the sample; and 2- and 3-MCPD as well as 3-MBPD, are then derivatized with phenylboronic acid prior to GC-MS/MS analysis. Free form of 3-MCPD and 2-MCPD are analyzed from another aliquot of the sample, modified from (4). Free form are extracted by a hexane-acetone mixture, followed by derivatization with phenylboronic acid prior to GC-MS/MS analysis. www.thermoscientific.com) or equivalent. (d) Ultrasonic cleaner .- SONICA® Ultrasonic Cleaner (Soltec, www.soltec.it) or equivalent. (e) Sample evaporator .- Reacti-Vap III Evaporator, 27-port (Thermo Scientific, art. TS-18826, www.thermoscientific.com) or equivalent. (f) Benchtop Centrifuge 3-18K .- (Satorius, www.sartorius.com) or equivalent. (g) Vacuum evaporator .- (Rocket Evaporator, Thermo Scientific, www.thermoscientific.com) or equivalent. Optional equipment as a sample evaporator (e) can also be used. (h) Homogenizer .- Geno Grinder 2010, Spex, art. 2010-230, www.spexcsp.com, or equivalent. (i) Ceramic homogenizer.- (Agilent, art. 5982-9313, http://www.agilent.com) or equivalent. (j) Conical tubes .- 50-mL conical tubes, polypropylene (Falcon, Corning art. 352070, www.corning.com) or equivalent (k) Conical tubes .- 15-mL conical tubes, polypropylene (Falcon, Corning art. 352096, www.corning.com) or equivalent B. Apparatus (a) Balances .- With readability of 0.1 mg and 0.01 g. (b) Vortex-mixer .-Vortex-Genie 2, G560E, www.scientificindustries.com) or equivalent. (c) Heating/Drying oven .- Heraeus Function 230V (Scientific Industries, Inc., Line Oven (Thermo Scientific,