AOAC 2018 Methods

3. 2-MCPD-d 5 : m/z = 201/203 4. 2-MCPD: m/z = 196/198

5. 3-MBPD-d 5 (glycidol-d 5 transformation product): m/z = 245/247 6. 3-MBPD (glycidol transformation product): m/z = 240/242 l. Target ions of corresponding labelled & unlabelled analytes should correspond for quantification

purposes in order to have constant response factors; 1. e.g. m/z = 150 vs. 147 (3-MCPD-d 5 vs. 3-MCPD) 2. e.g. m/z = 201 vs. 196 (2-MCPD-d 5 vs. 2-MCPD) 3. e.g. m/z = 245 vs. 240 (3-MBPD-d 5 vs. 3-MBPD)

Note: From practical experience, previous official method validation studies, and single-lab validation data related to this method, it can be concluded that for single quadrupole mass spectrometers coupled to gas chromatographic devices the response factors between the three isotope-labelled internal standards (3- MCPD-d 5 , 2-MCPD-d 5 , glycidol-d 5 ) and the non-labelled corresponding analytes (3-MCPD, 2-MCPD, glycidol) are close to 1 and not significantly concentration-dependent if corresponding target ions are

monitored. C. Reagents (a) 3-MCPD .—e.g., 99%, Dr. Ehrenstorfer GmbH (Augsburg, Germany).

(b) d 5 -3-MCPD .—e.g., 98%, Sigma-Aldrich (Steinheim, Germany).

(c) 2-MCPD. —e.g., 98%, Toronto Research Chemicals Inc. (Toronto, ON, Canada).

(d) d 5 -2-MCPD.— e.g., ≥ 98%, Toronto Research Chemicals Inc.

(e) 3-MCPD-1,2-dioleoyl ester .—e.g., 98%, Toronto Research Chemicals Inc.

(f) d 5 -3-MCPD-1,2-dioleoyl ester .—e.g. 98 %, Toronto Research Chemicals Inc.

(g) 2-MCPD-1,3-dipalmitoyl ester .—e.g., 98%, Toronto Research Chemicals Inc.

(h) d 5 -2-MCPD-1,3-dipalmitoyl ester .—e.g., 98%, Toronto Research Chemicals Inc.

(i) Glycidyl oleate .—e.g., 98%, Toronto Research Chemicals Inc.

(j) d 5 -Glycidyl oleate .—e.g., 98%, Toronto Research Chemicals Inc.

(k) Phenylboronic acid .—e.g., ≥ 97%, Sigma-Aldrich.

(l) Sodium sulphate .—Granulated, for organic trace analysis, Merck (Darmstadt, Germany). Before use the sodium sulphate should be baked out overnight in a muffle furnace at approx. 500°C. (m) Sodium bromide .—Ph Eur, Merck.