This piece highlights the disadvantages of utiising atomic force microscopy (AFM) for analysis of gun shot residue (GSR) and other fine powders. Also outlined is the origin of novel particle shapes that can be found in some published images

Jones, BJ

English

Crossref

Commentary on: Mou Y, Lakadwar J, Rabalais JW. Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR. J Forensic Sci 2008;53:1381-6.

Jones, B J

The University of Manchester - Institutional Repository

Commentary on: Mou Y, Lakadwar J, Rabalais JW. Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR. J Forensic Sci 2008;53:1381-6

Analysis of the presentation of gunshot residue assessment by atomic force microscopy (AFM) and summary of potential imaging artefacts

Jones, Benjamin

University of Huddersfield Repository

University of Huddersfield RepositoryJones, BenjaminCommentary on: Mou Y, Lakadwar J, Rabalais JW. Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR. J Forensic Sci 2008;53:1381–6Original CitationJones, Benjamin (2009) Commentary on: Mou Y, Lakadwar J, Rabalais JW. Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR. J Forensic Sci 2008;53:1381–6. Journal of Forensic Sciences, 54 (2). p. 502. ISSN 0022-1198 This version is available at http://eprints.hud.ac.uk/19568/The University Repository is a digital collection of the research output of theUniversity, available on Open Access. Copyright and Moral Rights for the itemson this site are retained by the individual author and/or other copyright owners.Users may access full items free of charge; copies of full text items generallycan be reproduced, displayed or performed and given to third parties in anyformat or medium for personal research or study, educational or not-for-profitpurposes without prior permission or charge, provided:• The authors, title and full bibliographic details is credited in any copy;• A hyperlink and/or URL is included for the original metadata page; and• The content is not changed in any way.For more information, including our policy and submission procedure, pleasecontact the Repository Team at: E.mailbox@hud.ac.uk.http://eprints.hud.ac.uk/B.J.Jones, Journal of Forensic Sciences 54 (2009) 502 ARCHIVE VERSION definitive version available via wiley.com or via DOI  http://dx.doi.org/10.1111/j.1556-4029.2009.00989.x   Commentary on: Mou Y, Lakadwar J, Rabalais JW. Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR. J Forensic Sci 2008;53:1381–6. B.J.Jones* The above paper highlights the use of atomic force microscopy (AFM) as a component technique for a possible new method of analysis of gunshot residue. The authors point out the non-destructive nature of AFM over the more routinely used scanning electron microscopy (SEM), which operates in vacuum and often requires the application of an additional conductive layer. However, AFM carries its own disadvantages: the image is obtained from a combination of the surface morphology of the sample to be studied and the shape of the scanning probe tip. In many cases, the effect of the tip shape can be discounted as negligible; however, there are particular problems when studying fine powders as one or more particles can become attached to the probe, significantly altering the size and shape of the imaging tip. This phenomenon can be manifested by an image mimicking the shape and orientation of the particle-probe combination repeatedly appearing over the image of the sample surface. This can significantly distort the resultant image and subsequent analysis, and is the potential origin of some of the novel particle shapes highlighted in this paper.  *b.j.jones@physics.org 

Commentary on: Mou Y, Lakadwar J, Rabalais JW. Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR. J Forensic Sci 2008;53:1381–6

Brunel University Research Archive

B.J. Jones “Commentary on “Evaluation of Shooting Distance by AFM and FTIR⁄ATR Analysis of GSR” Mou Y., Lakadwar J., Rabalais J.W., J. Forensic Sci. 2008; 53:1381-6” Journal of Forensic Sciences 54 (2009) 502 Archive Version.  Official version available online at http://www3.interscience.wiley.com or via DOI http://dx.doi.org/10.1111/j.1556-4029.2009.00989.x    Commentary on “Evaluation of Shooting Distance by AFM and FTIR⁄ATR Analysis of GSR” Mou Y., Lakadwar J., Rabalais J.W., J. Forensic Sci. 2008; 53:1381-6  Sir,  The above paper highlights the use of atomic force microscopy (AFM) as a component technique for a possible new method of analysis of gunshot residue.  The authors point out the non-destructive nature of AFM over the more routinely used scanning electron microscopy (SEM), which operates in vacuum and often requires the application of an additional conductive layer.  However, AFM carries its own disadvantages: the image is obtained from a combination of the surface morphology of the sample to be studied and the shape of scanning probe tip.  In many cases the effect of the tip shape can be discounted as negligible; however, there are particular problems when studying fine powders as one or more particles can become attached to the probe, significantly altering the size and shape of the imaging tip.  This phenomenon can be manifested by an image mimicking the shape and orientation of the particle-probe combination repeatedly appearing over the image of the sample surface.  This can significantly distort the resultant image and subsequent analysis, and is the potential origin of some of the novel particle shapes highlighted in this paper.       Benjamin J Jones PhD  Brunel University – Experimental Techniques Centre Kingston Lane, Uxbridge Middlesex UB8 3PH, UK 