Chemical Investigations Into the Lipid Fraction of Latent Fingermark Residue

Faculty of Science and Engineering Department of Chemistry Chemical Investigations into the Lipid Fraction of Latent Fingermark Residue Amanda Akiko Frick This thesis is presented for the Degree of Doctor of Philosophy of Curtin University January 2015 Declaration To the best of my knowledge and belief this thesis contains no material previously published by any other person except where due acknowledgment has been made. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. Signature: ……………………………… Date: ………19/01/2015…… i Abstract The lipid fraction of latent fingermark residue encompasses a number of stable and durable compounds crucial to fingermark detection on wetted porous substrates. Additionally, the complex nature of fingermark lipids, and the chemical changes undergone by several of these compounds as a function of time, may provide a means to extract valuable information from a fingermark, such as its age, and characteristics of the individual to whom it belongs. This thesis describes a number of investigations focused on the detection and chemical analysis of the lipid fraction of latent fingermarks. Two histological lipid stains were adapted for use as latent fingermark development reagents. It was found that Oil red O in propylene glycol yielded comparable results to a published Oil red O reagent, but has advantages in being less hazardous and simpler to prepare and use. The fatty acid stain Nile blue A was also investigated as a potential alternative to a novel Nile red reagent. It was found that the spontaneous hydrolysis of Nile blue A to Nile red in aqueous solution yielded a reagent that could develop latent fingermarks on a wide range of substrates, due to the presence of two lipid-sensitive compounds in one solution. The Nile blue reagent interacted with latent fingermarks on porous and some non-porous substrates to yield blue-purple impressions that, on several substrates, exhibit photoluminescence. Latent fingermark samples were collected on white copy paper from 148 donors to compare the relative performance of Oil red O and physical developer on both recently deposited samples, and those stored for 30 days. Physical developer was found to outperform Oil red O on both fresh and stored samples, with Oil red O performance significantly worsening on older samples. Statistical methods revealed that donor age, sex and recent use of skin products had significant influence on physical developer performance on recently deposited samples. This variation appeared to decrease with increased sample age. Latent fingermarks collected from 116 donors were analysed following solvent extraction. A simple gas chromatography-mass spectrometry method was developed for the detection of major fingermark lipid groups including free fatty acids, squalene, cholesterol and wax esters. Additional compounds were identified including components of cosmetic products and skin lotions, such as esters and vitamin E acetate. Principal component analysis was ii used as an exploratory tool to understand variation in fingermark composition and changes in such that occur as a function of time. No correlation to donor traits could be discerned, and oftentimes significant intra-donor variation was observed. Changes in fingermark composition due to degradation were observed over a 4 week period. The rate of fingermark lipid degradation was shown to be donor-specific, and influenced markedly by storage conditions. iii Acknowledgements There are many people who need to be thanked for somehow having the time and patience to help get me through the last 3 ½ years. It can’t be easy trying to turn a molecular biologist into an analytical chemist and I doubt anyone involved will ever be inclined to try this again. Firstly, I would like to thank my primary supervisor Professor Simon Lewis for taking me on as a PhD student in the first place – which I expect he regrets very much, given my worrying influence on his research group, and that time I filled his office with balloons. Yet somehow he has managed to put up with my abuse, good-natured and otherwise, over the years, so I suppose that counts for something. I would also like to thank my secondary supervisor Emeritus Professor Wilhelm van Bronswijk for his patience and advice, as well as keeping Simon from going completely mad. Immeasurable amounts of gratitude go to Geoff Chidlow for his invaluable advice regarding GC-MS and for basically saving a large and essential chunk of my project that was on the verge of burning down, falling over and sinking into the swamp. If not for his help I would have given up long ago, and I owe him a large bottle of something expensive. No doubt he needs it after putting up with me and my many hundreds of samples, and I hope the damage I have inflicted upon his precious instruments is not completely irreparable. To a lesser extent, I would also like to thank the now-Doctor Alex Holman for answering my questions regarding GC when I was too scared to talk to Geoff, even if he did keep pointing out that while geochemistry might not be as cool as forensics, at least rocks don’t disappear into meetings or go on leave when you need more samples. Additional thanks go to: Doctor John Goodpaster (who I suspect is some kind of wizard) for his guidance in data processing despite my utter terror at showing people my data; Doctor Richard Parsons for his advice on statistics that saved yet another chapter of this thesis; Doctor Alan Payne for drawing up a hydrolysis mechanism for a complete novice and not laughing at my incompetence with organic chemistry any more than he had to; Doctor Francesco Busetti for doing the Nile red identification at the cost of his MS being stained indelibly pink; and Peter Chapman for his general expertise in all things tech-related, and his somewhat questionable sense of humour. iv They’ll whinge if they don’t get a mention, so I’d like to thank the forensics group as a whole for keeping things interesting and going along with my insane schemes. More specific thanks go to Mark Maric, Karin van der Pal and Georgina Sauzier for helping make sense of the chemometrics, and Patrick Fritz for a productive partnership based on mutual hatred, similar PhD projects, that damned donor study and vast amounts of coffee. Of course, I must acknowledge the contribution of all the fingermark donors, without whom there would be no thesis at all. Especial thanks go to those luckless few who were made to participate in multiple experiments, asked to drop everything several times a day to provide samples, or were bothered mercilessly for resampling. And lastly, I’d like to thank all those in the Curtin University Department of Chemistry that I have not mentioned above for their support over the last few years. v Publications A.A. Frick, F. Busetti, A. Cross, S.W. Lewis, Aqueous Nile blue: a simple, versatile and safe reagent for the detection of latent fingermarks. Chemical Communications, 2014. 50(25): p. 3341-3343. A.A. Frick, P. Fritz, S.W. Lewis, and W. van Bronswijk, Sequencing of a modified Oil Red O development technique for the detection of latent fingermarks on paper surfaces. Journal of Forensic Identification, 2013. 63(4): p. 369-385. Zadnik, S., W. Van Bronswijk, A. A. Frick, P. Fritz, and S. W. Lewis, Fingermark simulants and their inherent problems: A comparison with latent fingermark deposits. Journal of Forensic Identification, 2013. 63(5): p. 593-608. A.A. Frick, P. Fritz, S.W. Lewis, Chemistry of Print Residue, in Encyclopedia of Forensic Sciences, J.A. Siegel and P.J. Saukko, Editors. 2013, Academic Press: San Diego. p. 92-97. G. Sauzier, A.A. Frick, and S.W. Lewis, Investigation into the performance of modified silver physical developers for visualizing latent fingermarks on paper. Journal of Forensic Identification, 2013. 63(1): p. 70-89. A.A. Frick, P. Fritz, S.W. Lewis, W. van Bronswijk, A modified Oil Red O reagent for the detection of latent fingermarks on porous substrates. Journal of Forensic Identification, 2012. 62(6): p. 623-641. vi Conference presentations Nile blue as a simple, versatile reagent for latent fingermark detection. 22nd International Symposium on the Forensic Sciences of the Australian and New Zealand Forensic Science Society, Adelaide. October 2014. Investigations into the variability of fresh and degraded fingermark lipids. 22nd International Symposium on the Forensic Sciences of the Australian and New Zealand Forensic Science Society, Adelaide. October 2014. Detection of latent fingermarks using a modified Oil Red O reagent. 21st International Symposium on the Forensic Sciences of the Australian and New Zealand Forensic Science Society, Hobart. September 2012. vii Table of contents Declaration .......................................................................................................................... i Abstract .............................................................................................................................. ii Acknowledgements ............................................................................................................ iv Publications ........................................................................................................................ vi Conference presentations ................................................................................................. vii Table of contents .............................................................................................................

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