In the paper “Eco-friendly ionic liquid based ultrasonic assisted selective extraction coupled with a simple liquid chromatography for the reliable determination of acrylamide in food samples” a reliable technique to detect acrylamide in bread and potato chips was proposed. Ionic liquid-based ultrasonic-assisted extraction (ILUAE), liquid chromatography (LC) and UV spectroscopy were used to develop the analytical method. A 100% water solution was chosen as the chromatographic mobile phase. However, the latter was already used by V. Gökmen et al and F. Khoshman et al. to detect acrylamide in potato chips and crisp by LC-UV with comparable or better performance parameters, namely limit of detection (LOD) and recovery (Vural Gökmen, Hamide Z. Şenyuva, Jale Acara, Kemal Sarıoğlu, Determination of acrylamide in potato chips and crisps by high-performance liquid chromatography, J. Chromatogr. A, 1088 (2005) 193–199 AND F.Khoshnam, B. Zargar, N. Pourreza, H. Parham, Acetone extraction and HPLC determination of acrylamide in potato chips, J. Iran. Chem. Soc. 7 (2010) 856-858).

Consequently, the proposed LC-UV method lack of innovation. Conversely, to the best of my knowledge, ILUAE was never used to extract acrylamide from food sample. In addition, there are few mistakes in bibliography, and references are not always properly cited. The validation procedure is vague and incorrect and ILUAE development is non-exhaustive.

INTRODUCTION

The introduction is clear. However, the ILs green properties were not properly described and supported by bibliographical references. References number 1 and 2 are inadequate to demonstrate that ILs are eco-friendly solvents and that the number of their applications has increased. The authors should add bibliographical references to support their statements. Reference number 3 does not deal with the use of ILs to extract organic compounds, but it is about ILs toxicity. In references number 13 and 14 there is no information about the daily intake of acrylamide from food.

There are some mistakes in bibliographical references. The reference number 10 is wrongly numbered. It was mentioned only after the references number 11, 12, 13 and 14. The reference number 15 is equal to reference number 11. The authors should check the sequence of references and correct the typos.

The state of art is not properly discussed. The authors stated that “…a substantial amount of previous works on the determination of acrylamide…”, but they cited only two earlier paper (see references number 17 and 18). The authors should increase the bibliographical references on existing analytical method to detect acrylamide in foodstuffs in order to support their statements.

EXPERIMENTAL

Paragraph 2.4 and most of its subsection are unclear and inaccurate. The authors declared that two validation procedures were used to validate the proposed method, namely Commission Decision 657/2002 and US FDA Guidance for Industry. However, these two procedures are different. Therefore, two distinct validation processes are expected to be described. Conversely, only one was proposed. Furthermore, it is essential to specify method category before choosing which performance parameters should be assessed. However, this information was not provided.

Finally, the description of the performance parameters (selectivity, accuracy, recovery, precision, robustness, and stability) is inaccurate and it is not compliant to neither of the validation procedures. Consequently, the authors should be more accurate on (i) the validation procedure they intend to perform, (ii) the method category, (iii) which performance parameters have to be assessed, (iv) how they shall determine the above parameters.

RESULT AND DISCUSSION

-Method development-

In several places of subsection 3.1.1.1 the author stated that acrylamide toxicity is due to its dual polar and non-polar nature. However, they did not support that statement with experimental proofs or bibliographical research. Consequently, the authors should eliminate the above phrases or add bibliographical references as support.

In 3.1.2 the authors described the optimization procedure for acrylamide extraction by ILUAE. However, in subsection 3.1.2.1 the discussion on IL type selection is non-exhaustive. 1-butyl-3-methylim-midazolium bromide (BMIMBr) was chosen in view of a previous work on the development of a sample preparation method for isoliquiritigenin, liquiritin, and glycyrrhizic acid in liquorice. However, both the analytes and the food samples are different; hence, BMIMBr may not be the best IL to extract acrylamide from potato chips and bread. The authors should examine others ILs prior to state that 1-butyl-3-methylim-midazolium bromide (BMIMBr) is the best choice.

Figure 3B is unclear. The graphical representation seems to be in conflict with the information written in subsection 3.1.2.2. The authors should review both the above graphic and its explanation.

-Method validation-

The method validation is inaccurate as already outlined before. Furthermore, information on both the statistical tests used to accept the null hypothesis and the equation of the calibration curve was not provided. The authors should determine the performance parameters again according to validation procedures guidelines and supplement the missing information.