*2.3. Chemicals*

All solvents and reagents were of analytical grade. Acrylamide, with a purity of 99% to be used as the external standard, acrylamide-2,3,3-d3 (acrylamide d3), with a purity of 99% to be used as the internal standard, and acetonitrile (Chromasolv® Plus purity for LC-MS) were obtained from Sigma-Aldrich Merck KGaA (Milan, Italy).

QuEChERS pouches containing MgSO4 4.0 g + NaCl 0.5 g were purchased from Agilent Technologies Italia S.p.A. (Milan, Italy). Deionized water was obtained through an Elix 3UV purification system (Millipore Merck KgaA, Milan, Italy).

### *2.4. Biscuit Size*

The size parameters (thickness, length, and width) of the biscuits were measured 1 h after baking with the use of a vernier caliper.
