AOAC 2018 Methods

(l) Vials .- 10mL Glass vial (Thermo Scientific, art. TS-13225, www.thermoscientific.com or equivalent. (m) Amber vials .-2 mL amber screw top vial, with write-on spot (Agilent, art. 5182-0716, www.agilent.com) or equivalent. (n) Vial screw caps .-blue screw cap, PTFE/red silicone septum (Agilent, art. 5182-0717, www.agilent.com) or equivalent (o) Glass vial inserts .-400 µL flat bottom glass vial insert (Agilent, art. 5181-3377, www.agilent.com) or equivalent. (p) SPE column.- Supelclean™ LC-NH2 SPE tube - 500 mg, 6 mL (Sigma Aldrich, art. 54059-U) or equivalent (q) Gas Chromatograph and GC columns .- Agilent 7890A GC (MMI injector with Ultra inert Inlet Liner, 2 mm dimpled; Agilent, art.5190-4006) and 7693 ALS Autosampler (e.g. Agilent, www.agilent.com), or equivalent. When no MMI is installed, a SSL injector can be used. Two Agilent HP-5ms columns (19091S-431, 15 m length x 0.25 mm i.d. x 0.25 µm film thickness) connected via a back-flush system. Pre-column placed before column 1: 2 m cut from Agilent HP-5ms columns (19091S-431, 15 m length x 0.25 mm i.d. x 0.25 µm film thickness), or equivalent. Alternatively when no backflush is installed, one Agilent HP-5ms column (19091S- 433, 30 m length x 0.25 mm i.d. x 0.25 µm film thickness) can be used. Operating conditions: carrier gas, helium in constant flow mode at 1.2 mL/min; injection volume, 0.5 µL in splitless mode; septum purge flow, 3 mL/min; purge flow to split vent at 30 mL/min after 3 min; MMI temperature program, 80°C hold for 0.02 min, 500°C/min to 300°C, 325°C during post run; GC oven temperature program, 60°C hold for 1 min, 10°C/min to 200°C, 25°C/min to 250°C, 260°C during post run; backflush condition during post run, backflush pressure 50 psi for 3 min, inlet pressure at 2 psi. (r) Triple quadrupole mass spectrometer .- Agilent 7000C Triple Quadrupole GC-MS/MS System with tandem MS (MS/MS) instrument (Agilent, www.agilent.com). Operating conditions: Electron-Impact (EI), Multiple Reaction Monitoring (MRM) mode, low mass resolution, transfer line temperature 280°C, source temperature 280°C. Solvent delay, 3 min, time segment 1 from 0 to 12.9 min, time segment 2 from 12.9 min to end of run. See Table 2018.03A for transitions reactions monitored and corresponding collision energy. Typical chromatogram is given in Figure 2018.03A . Commercial references are only a guideline. Use equivalent chemicals or materials when listed items are not locally available. Before using chemicals, refer to the safety data sheets and ensure that the safety precautions are applied. - It is recommended to check for the presence of other isomers in each standard (e.g. presence of 3-MCPD in 2-MCPD, or presence of 1,2-Dipalmitoyl-3-chloropropanediol-d5 in 1,3-Dipalmitoyl-2-chloropropanediol-d5). - When a specific MCPD or glycidyl ester of fatty acid is mentioned in the standard below, another fatty acid ester can be used as soon as performances of the method are not impacted (e.g. use of glycidyl oleate instead of glycidyl palmitate) (a) rac 1,2-Bis-palmitoyl-3-chloropropanediol.- (TRC, art. B515200, www.trc-canada.com) or equivalent. CAS No. 51930-97-3: PP-3-MCPD, 98% chemical purity. (b) rac 1,2-Bis-palmitoyl-3-chloropropanediol-d5 .- (TRC, art. B515202, www.trc-canada.com) or equivalent. CAS No. 1185057-55-9: PP-3-MCPD-d5, 98% chemical purity, > 98% isotopic purity. Notes: -

C. Reagents