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Mallikarjun A, Charendoff I, Moore MB, Wilson C, Nguyen E, Hendrzak AJ, Poulson J, Gibison M, Otto CM. Assessing Different Chronic Wasting Disease Training Aids for Use with Detection Dogs. Animals (Basel) 2024; 14:300. [PMID: 38254469 PMCID: PMC10812555 DOI: 10.3390/ani14020300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Chronic wasting disease (CWD) is a highly infectious, fatal prion disease that affects cervid species. One promising method for CWD surveillance is the use of detection dog-handler teams wherein dogs are trained on the volatile organic compound signature of CWD fecal matter. However, using fecal matter from CWD-positive deer poses a biohazard risk; CWD prions can bind to soil particles and remain infectious in contaminated areas for extended periods of time, and it is very difficult to decontaminate the affected areas. One solution is to use noninfectious training aids that can replicate the odor of fecal matter from CWD-positive and CWD-negative deer and are safe to use in the environment. Trained CWD detection dogs' sensitivity and specificity for different training aid materials (cotton, GetXent tubes, and polydimethylsiloxane, or PDMS) incubated with fecal matter from CWD-positive and CWD-negative deer at two different temperatures (21 °C and 37 °C) for three different lengths of time (6 h, 24 h, and 48 h) were evaluated. Cotton incubated at 21 °C for 24 h was identified as the best aid for CWD based on the dogs' performance and practical needs for training aid creation. Implications for CWD detection training and for training aid selection in general are discussed.
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Affiliation(s)
- Amritha Mallikarjun
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Ila Charendoff
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Madison B. Moore
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Clara Wilson
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Elizabeth Nguyen
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Abigail J. Hendrzak
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Jean Poulson
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
| | - Michelle Gibison
- Wildlife Futures Program, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348, USA;
| | - Cynthia M. Otto
- Penn Vet Working Dog Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19146, USA (M.B.M.); (C.W.); (E.N.); (A.J.H.); (J.P.); (C.M.O.)
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, PA 19104, USA
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de Miranda-Magalhães AJ, Jantorno GM, Pralon AZ, de Castro MB, de Melo CB. Explosive Detection Dogs: A Perspective from the Personality Profile, Selection, Training Methods, Employment, and Performance to Mitigate a Real Threat. Animals (Basel) 2023; 13:3773. [PMID: 38136810 PMCID: PMC10741240 DOI: 10.3390/ani13243773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 11/26/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
Terrorist organizations have compelled security authorities of every nation to make an increasingly significant commitment toward mitigating the risk of mass casualties and severe financial and property damages. As a result, various security measures have been implemented, including the use of advanced equipment and an uptick in intelligence activities. One of the most effective tools that has yielded outstanding results is the use of explosive detection dogs (EDDs). The nature of EDDs demands a high level of sensitivity given the inherent danger and severity of real threat situations that may involve the risk of explosion. Moreover, the operating procedures for EDDs are unique and distinguishable from other forms of detection. We conducted a review to ensure a comprehensive understanding of the subject, highlighting the EDDs' personality profile, selection, training methods, performance, and employment, incorporating insights from diverse fields, conducting an analysis, and presenting a perspective on using EDDs to prevent explosion threats.
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Affiliation(s)
- Antônio J. de Miranda-Magalhães
- Graduate Program in Animal Sciences (PPGCA/FAV), University of Brasilia (UnB), Campus Darcy Ribeiro ICC Sul, Asa Norte, Brasília 70910-900, Federal District, Brazil; (A.J.d.M.-M.); (G.M.J.); (M.B.d.C.)
| | - Gustavo M. Jantorno
- Graduate Program in Animal Sciences (PPGCA/FAV), University of Brasilia (UnB), Campus Darcy Ribeiro ICC Sul, Asa Norte, Brasília 70910-900, Federal District, Brazil; (A.J.d.M.-M.); (G.M.J.); (M.B.d.C.)
| | - Adauto Z. Pralon
- Bomb and Explosives Group (GBE), Policia Federal (PF/SRES), Brasília 70037-900, Federal District, Brazil;
| | - Márcio B. de Castro
- Graduate Program in Animal Sciences (PPGCA/FAV), University of Brasilia (UnB), Campus Darcy Ribeiro ICC Sul, Asa Norte, Brasília 70910-900, Federal District, Brazil; (A.J.d.M.-M.); (G.M.J.); (M.B.d.C.)
| | - Cristiano Barros de Melo
- Graduate Program in Animal Sciences (PPGCA/FAV), University of Brasilia (UnB), Campus Darcy Ribeiro ICC Sul, Asa Norte, Brasília 70910-900, Federal District, Brazil; (A.J.d.M.-M.); (G.M.J.); (M.B.d.C.)
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Abstract
Volatolomics allows us to elucidate cell metabolic processes in real time. In particular, a volatile organic compound (VOC) excreted from our bodies may be specific for a certain disease, such that measuring this VOC may afford a simple, fast, accessible and safe diagnostic approach. Yet, finding the optimal endogenous volatile marker specific to a pathology is non-trivial because of interlaboratory disparities in sample preparation and analysis, as well as high interindividual variability. These limit the sensitivity and specificity of volatolomics and its applications in biological and clinical fields but have motivated the development of induced volatolomics. This approach aims to overcome issues by measuring VOCs that result not from an endogenous metabolite but, rather, from the pathogen-specific or metabolic-specific enzymatic metabolism of an exogenous biological or chemical probe. In this Review, we introduce volatile-compound-based probes and discuss how they can be exploited to detect and discriminate pathogenic infections, to assess organ function and to diagnose and monitor cancers in real time. We focus on cases in which labelled probes have informed us about metabolic processes and consider the potential and drawbacks of the probes for clinical trials. Beyond diagnostics, VOC-based probes may also be effective tools to explore biological processes more generally.
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Simon A, Lazarowski L, Singletary M, Barrow J, Van Arsdale K, Angle T, Waggoner P, Giles K. A Review of the Types of Training Aids Used for Canine Detection Training. Front Vet Sci 2020; 7:313. [PMID: 32596267 PMCID: PMC7301692 DOI: 10.3389/fvets.2020.00313] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/06/2020] [Indexed: 12/04/2022] Open
Abstract
The canine detection community is a diverse one, ranging from scientific fields such as behavior, genetics, veterinary medicine, chemistry, and biology to applications in law enforcement, military, medicine, and agricultural/environmental detection. This diversity has allowed for a flourishing and innovative community, yet it has also led to little acceptance and agreement on terminology. This is especially true when discussing the variety of training aids used in olfactory-based exercises. In general, authentic materials and pseudo-scents are the most commonly discussed, with the former accepted widely for training and certification, and the latter more often disregarded. However, as advances are made in the creation of training materials, alternative training aids are being introduced that do not fit into either of these categories. The misconceptions surrounding how these alternative training aids are manufactured has led to confusion on their classification, and therefore their reliance as an effective tool. This manuscript will review the existing language surrounding canine training aids, address relevant research revealing effectiveness, and clarify the different types based on their manufacture, chemical nature, and fundamental function.
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Affiliation(s)
- Alison Simon
- AGS Forensics, LLC, Washington, DC, United States
| | - Lucia Lazarowski
- Canine Performance Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Melissa Singletary
- Canine Performance Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Jason Barrow
- Federal Bureau of Investigation Laboratory, Quantico, VA, United States
| | - Kelly Van Arsdale
- Federal Bureau of Investigation Laboratory, Quantico, VA, United States
| | - Thomas Angle
- Canine Performance Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Paul Waggoner
- Canine Performance Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Kathleen Giles
- Giles Consulting, LLC, Huntington Beach, CA, United States
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Cannon C, Stejskal S, Perrault KA. The volatile organic compound profile from Cimex lectularius in relation to bed bug detection canines. Forensic Chem 2020. [DOI: 10.1016/j.forc.2020.100214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Moser AY, Bizo L, Brown WY. Olfactory Generalization in Detector Dogs. Animals (Basel) 2019; 9:E702. [PMID: 31546835 PMCID: PMC6769875 DOI: 10.3390/ani9090702] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 11/21/2022] Open
Abstract
Generalizing to target odor variations while retaining specificity against non-targets is crucial to the success of detector dogs under working conditions. As such, the importance of generalization should be considered in the formulation of effective training strategies. Research investigating olfactory generalization from pure singular compounds to more complex odor mixtures helps to elucidate animals' olfactory generalization tendencies and inform ways to alter the generalization gradient by broadening or narrowing the range of stimuli to which dogs will respond. Olfactory generalization depends upon both intrinsic factors of the odors, such as concentration, as well as behavioral and cognitive factors related to training and previous experience. Based on the current research, some training factors may influence generalization. For example, using multiple target exemplars appears to be the most effective way to promote elemental processing and broaden the generalization gradient, whereas increasing the number of training instances with fewer exemplars can narrow the gradient, thereby increasing discrimination. Overall, this research area requires further attention and study to increase our understanding of olfactory generalization in dogs, particularly detector dogs, to improve training and detection outcomes.
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Affiliation(s)
- Ariella Y Moser
- Canine and Equine Research Group, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
| | - Lewis Bizo
- School of Psychology, University of New England, Armidale, NSW 2351, Australia.
| | - Wendy Y Brown
- Canine and Equine Research Group, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
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Simon AG, DeGreeff LE. Variation in the headspace of bulk hexamethylene triperoxide diamine (HMTD): Part II. Analysis of non-detonable canine training aids. Forensic Chem 2019. [DOI: 10.1016/j.forc.2019.100155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Prada PA, Furton KG. Birds and Dogs: Toward a Comparative Perspective on Odor Use and Detection. Front Vet Sci 2018; 5:188. [PMID: 30155472 PMCID: PMC6103309 DOI: 10.3389/fvets.2018.00188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
While canines are generally considered the gold standard for olfactory detection in many situations other animals provide alternatives and offer a unique opportunity to compare biological detection capabilities. Critical components in successfully studying biological detectors is not only understanding their anatomical evidence for olfaction, but also, understanding the life history of the species to better direct the potential of an olfactory task. Here, a brief overview is provided presenting a comparative viewpoint on the use of odors by birds and canines over a range of unique detection scenarios. Similar to canines, birds use olfactory information in various natural oriented contexts where odors are dispersed over a widespread spatial range. Comparing these two distinctive animal models, and current trends in physiological and behavioral assessments may open the door for novel uses of birds as biological sensors in forensic applications.
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Affiliation(s)
- Paola A Prada
- Department of Environmental Toxicology, Institute for Forensic Science, Texas Tech University, Lubbock, TX, United States
| | - Kenneth G Furton
- Department of Chemistry and Biochemistry, International Forensic Research Institute, Florida International University, Miami, FL, United States
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Hayes J, McGreevy P, Forbes S, Laing G, Stuetz R. Critical review of dog detection and the influences of physiology, training, and analytical methodologies. Talanta 2018; 185:499-512. [DOI: 10.1016/j.talanta.2018.04.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/04/2018] [Accepted: 04/04/2018] [Indexed: 02/06/2023]
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Knobel Z, Ueland M, Nizio KD, Patel D, Forbes SL. A comparison of human and pig decomposition rates and odour profiles in an Australian environment. AUST J FORENSIC SCI 2018. [DOI: 10.1080/00450618.2018.1439100] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Zaccariah Knobel
- Centre for Forensic Science, University of Technology Sydney, Broadway, Australia
| | - Maiken Ueland
- Centre for Forensic Science, University of Technology Sydney, Broadway, Australia
| | - Katie D. Nizio
- Centre for Forensic Science, University of Technology Sydney, Broadway, Australia
| | - Darshil Patel
- Centre for Forensic Science, University of Technology Sydney, Broadway, Australia
| | - Shari L. Forbes
- Centre for Forensic Science, University of Technology Sydney, Broadway, Australia
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12
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The analysis of textiles associated with decomposing remains as a natural training aid for cadaver-detection dogs. Forensic Chem 2017. [DOI: 10.1016/j.forc.2017.06.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Verheggen F, Perrault KA, Megido RC, Dubois LM, Francis F, Haubruge E, Forbes SL, Focant JF, Stefanuto PH. The Odor of Death: An Overview of Current Knowledge on Characterization and Applications. Bioscience 2017. [DOI: 10.1093/biosci/bix046] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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14
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Rust L, Nizio KD, Forbes SL. The influence of ageing and surface type on the odour profile of blood-detection dog training aids. Anal Bioanal Chem 2016; 408:6349-60. [DOI: 10.1007/s00216-016-9748-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/20/2016] [Accepted: 06/27/2016] [Indexed: 11/28/2022]
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Armstrong P, Nizio KD, Perrault KA, Forbes SL. Establishing the volatile profile of pig carcasses as analogues for human decomposition during the early postmortem period. Heliyon 2016; 2:e00070. [PMID: 27441249 PMCID: PMC4945964 DOI: 10.1016/j.heliyon.2016.e00070] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/09/2015] [Accepted: 01/21/2016] [Indexed: 10/30/2022] Open
Abstract
Following a mass disaster, it is important that victims are rapidly located as the chances of survival decrease greatly after approximately 48 h. Urban search and rescue (USAR) teams may use a range of tools to assist their efforts but detector dogs still remain one of the most effective search tools to locate victims of mass disasters. USAR teams can choose to deploy human scent dogs (trained to locate living victims) or human remains detection (HRD) dogs (trained to locate deceased victims). However, little is known about the variation between live human scent and postmortem human remains scent and the timeframe during which one type of scent transitions to the other. The aim of the current study was to measure the change in the scent profile of human decomposition analogues during the first 72 h postmortem by measuring the volatile organic compounds (VOCs) that comprise the odour. Three pig carcasses (Sus scrofa domesticus L.) were placed on a soil surface and allowed to decompose under natural conditions. Decomposition odour was sampled frequently up to 75 h postmortem and analysed using comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC×GC-TOFMS). A total of 105 postmortem VOCs were identified during the early postmortem period. The VOC profile during the early postmortem period was highly dynamic, changing both hourly and daily. A transition period was observed after 43 h postmortem, where the VOC profile appeared to shift from a distinct antemortem odour to a more generalised postmortem odour. These findings are important in informing USAR teams and their use of detector dogs for disaster victim recovery.
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Affiliation(s)
- P Armstrong
- Centre for Forensic Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - K D Nizio
- Centre for Forensic Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - K A Perrault
- Centre for Forensic Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - S L Forbes
- Centre for Forensic Science, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
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Rice S, Koziel JA. The relationship between chemical concentration and odor activity value explains the inconsistency in making a comprehensive surrogate scent training tool representative of illicit drugs. Forensic Sci Int 2015; 257:257-270. [PMID: 26427020 DOI: 10.1016/j.forsciint.2015.08.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/21/2015] [Accepted: 08/31/2015] [Indexed: 11/27/2022]
Abstract
This report highlights the importance of an individual chemical's odor impact in the olfactory identification of marijuana, cocaine, and heroin. There are small amounts of highly odorous compounds present in headspace of these drugs, with very low odor detection thresholds, that are more likely responsible for contributing to the overall odor of these drugs. Previous reports of the most abundant compounds in headspace can mislead researchers when dealing with whole odor of these drugs. Surrogate scent formulations, therefore, must match the odor impact of key compounds and not just the chemical abundance of compounds. The objective of this study was to compare odorous volatile organic compounds (VOCs) emitted from illicit drug samples of marijuana, cocaine, and heroin to surrogate smell formulations using simultaneous sensory (via human olfaction) and chemical analyses. Use of solid phase microextraction (SPME) allowed VOCs in drug headspace to be extracted and pre-concentrated on site, and analyzed by multidimensional gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O). Use of MDGC-MS-O allowed for further separation of odorous compounds and simultaneous detection by the human nose of the separate odor parts that make up the total aroma of these drugs. The compounds most abundant in headspace were not the most odor impactful when ranked by odor activity values (OAVs) (defined as ratio of concentration to odor detection threshold, ODT). There were no apparent correlations between concentrations and OAVs. A 1g marijuana surrogate lacked in odor active acids, aldehydes, ethers, hydrocarbons, N-containing, and S-containing VOCs and was overabundant in odor active alcohols and aromatics compared with real marijuana. A 1g cocaine surrogate was overabundant in odor active alcohols, aldehydes, aromatics, esters, ethers, halogenates, hydrocarbons, ketones and N-containing compounds compared with real. A 1g heroin surrogate should contain less odor active acids, alcohols, aromatics, esters, ketones, and N-containing compounds. Drug quantity, age and adulterants can affect VOC emissions and their odor impact. The concept of odor activity value, then, is useful to researchers without access to more sophisticated instrumentation. Odor activity values can be calculated from published odor detection thresholds. More research is warranted to expand the database, and determine odor detection thresholds for compounds of interest. Additional information could be obtained from establishing ODTs of key odorants for canines.
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Affiliation(s)
- Somchai Rice
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, United States; Interdepartmental Toxicology Graduate Program, Iowa State University, Ames, IA 50011, United States
| | - Jacek A Koziel
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA 50011, United States; Interdepartmental Toxicology Graduate Program, Iowa State University, Ames, IA 50011, United States.
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Perrault KA, Nizio KD, Forbes SL. A Comparison of One-Dimensional and Comprehensive Two-Dimensional Gas Chromatography for Decomposition Odour Profiling Using Inter-Year Replicate Field Trials. Chromatographia 2015. [DOI: 10.1007/s10337-015-2916-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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18
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Forbes SL, Perrault KA, Stefanuto PH, Nizio KD, Focant JF. Comparison of the decomposition VOC profile during winter and summer in a moist, mid-latitude (Cfb) climate. PLoS One 2014; 9:e113681. [PMID: 25412504 PMCID: PMC4239107 DOI: 10.1371/journal.pone.0113681] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 10/29/2014] [Indexed: 11/18/2022] Open
Abstract
The investigation of volatile organic compounds (VOCs) associated with decomposition is an emerging field in forensic taphonomy due to their importance in locating human remains using biological detectors such as insects and canines. A consistent decomposition VOC profile has not yet been elucidated due to the intrinsic impact of the environment on the decomposition process in different climatic zones. The study of decomposition VOCs has typically occurred during the warmer months to enable chemical profiling of all decomposition stages. The present study investigated the decomposition VOC profile in air during both warmer and cooler months in a moist, mid-latitude (Cfb) climate as decomposition occurs year-round in this environment. Pig carcasses (Sus scrofa domesticus L.) were placed on a soil surface to decompose naturally and their VOC profile was monitored during the winter and summer months. Corresponding control sites were also monitored to determine the natural VOC profile of the surrounding soil and vegetation. VOC samples were collected onto sorbent tubes and analyzed using comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC-TOFMS). The summer months were characterized by higher temperatures and solar radiation, greater rainfall accumulation, and comparable humidity when compared to the winter months. The rate of decomposition was faster and the number and abundance of VOCs was proportionally higher in summer. However, a similar trend was observed in winter and summer demonstrating a rapid increase in VOC abundance during active decay with a second increase in abundance occurring later in the decomposition process. Sulfur-containing compounds, alcohols and ketones represented the most abundant classes of compounds in both seasons, although almost all 10 compound classes identified contributed to discriminating the stages of decomposition throughout both seasons. The advantages of GC×GC-TOFMS were demonstrated for detecting and identifying trace levels of VOCs, particularly ethers, which are rarely reported as decomposition VOCs.
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Affiliation(s)
- Shari L. Forbes
- Centre for Forensic Science, University of Technology Sydney, Broadway, NSW, Australia
- * E-mail:
| | - Katelynn A. Perrault
- Centre for Forensic Science, University of Technology Sydney, Broadway, NSW, Australia
| | - Pierre-Hugues Stefanuto
- CART, Organic and Biological Analytical Chemistry Group, Chemistry Department, University of Liège, Liège, Belgium
| | - Katie D. Nizio
- Centre for Forensic Science, University of Technology Sydney, Broadway, NSW, Australia
| | - Jean-François Focant
- CART, Organic and Biological Analytical Chemistry Group, Chemistry Department, University of Liège, Liège, Belgium
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