Review of Element Analysis of Industrial Materials by In-Line Laser—Induced Breakdown Spectroscopy (LIBS)
, Stefan Trautner 1, Stefan Grünberger 1, Nikolaos Giannakaris 1, Simon Eschlböck-Fuchs 2 and Josef Hofstadler 2Round 1
Reviewer 1 Report
I have reviewed the paper entitled Review of Element Analysis of Industrial Materials by in-line Laser-Induced Breakdown Spectroscopy (LIBS) and I should congratulate the authors for the wonderful and extensively deep review analysis they have performed when preparing this manuscript. The paper is well-written, well-structured, clear and easy to read. They cover a broad number of different applications of in-line LIBS analysis and point out the advantages of this system. However, this reviewer suggests some improvements to make the paper even better before it can be accepted for publication:
1) There are several subsections describing how LIBS sensors can be used in the recycling sector at different levels, e.g. recovery of secondary raw materials such as Al, PVC, etc or during the production of plastics after recovery. However, a big challenge there is the contamination/pollution of the surface. It can severely affect the measurements performed. This is especially the case for sorting applications in a conveyor-type industrial system where it is not always possible to shot more than few pulses on the same point. Is there any literature on how to deal with these questions? Maybe mechanically, by modifying the way in which you shoot the sample? Or maybe numerically, by analyzing the gathered spectra?
2) At the end of the manuscript or in the conclusions section, it would be convenient to talk about the limitations of LIBS sensors and/or specific limitations for some important applications. In addition, and related to this and to point 1), a description of the main challenges when using the LIBS technology and how are being (or could be) addressed will improve a lot the paper as the review will also include limitations/challenges/and prospective future research lines.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Your review is wonderful and rewarding! I recommend it for publication. Minor corrections that do not touch upon the essence of the work, but will help the reader become better understand it.
Figure 2 - I recommend redrawing. The reader may not immediately understand the correspondence between the abscissa axis and groups of chemical elements, because of this, confusion will arise in the presented data. A possible fix is attached. You also need to indicate the source in the title - "... according to the IUPAC scheme [54]."
Blurred image in Figure 5b. The reader may want to familiarize himself with the data presented in this figure in more detail. In source [453] it is clearer, it should be replaced with a sharp version.
Same for Figures 13a [259], 13b [263].
Where did Figure 14b come from? In [460], it is absent. You must indicate the source.
Comments for author File: Comments.rar
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
