160 ◦C (3 min) − 160 ◦C (2 min + STR 40% r.h.) − 140 ◦C (3 min)

#### *3.3. Validation of the MS/MS Parameters*

Table 2 shows the optimized parameters (dwell time, fragmentor voltage, and collision energy). Both the coefficients of determination (R2) of the acrylamide to acrylamide d3 ratio calibration straight lines that were calculated using (1) aqueous acrylamide solutions of known concentration and (2) analyte-free biscuit matrix with additions of known acrylamide concentrations were higher than 0.99 (Table 2). This demonstrated a satisfactory linear correlation between concentration and response, also confirmed by visual inspection [29].

**Table 2.** List of the main MS parameters optimized and results of the method validation.


ESI: electrospray ionization; R2: coefficient if determination; LOD: limit of detection; LLOQ: lower limit of quantification (LLOQ); RSD, relative standard deviation.

Regarding detectability, the LOD and LLOQ values were respectively 0.03 mg/L and 0.10 mg/L, which are far lower than the concentration of acrylamide in the extracts and also lower compared with the values found in previous studies carried out with SPE extraction [30,31]. Precision was well within 10% in all tests performed.

Trueness was assessed in terms of percentage recovery of acrylamide solutions spiked at different concentrations using biscuit matrix previously deprived of the analyte. Results showed an excellent average recovery of 98.31%.
