Identification of dominant odor chemicals emanating from explosives for use in developing optimal training aid combinations and mimics for canine detection (original) (raw)
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Evaluation of the odor compounds sensed by explosive-detecting canines
2010
Lotspeich, Erica, H. M.S., Purdue University, August, 2010. Evaluation of the Odor Compounds Sensed by Explosive-Detecting Canines. Major Professor: John V. Goodpaster. Trained canines are commonly used as biological detectors for explosives; however, there are some areas of uncertainty that have led to difficulties in canine training and testing. Even though a standardized container for determining the accuracy of explosives-detecting canines has already been developed, the factors that govern the amount of explosive vapor that is present in the system are often uncertain. This has led to difficulties in comparing the sensitivity of canines to one another as well as to analytical instrumentation, despite the fact that this container has a defined headspace and degree of confinement of the explosive. For example, it is a common misconception that the amount of explosive itself is the chief contributor to the amount of odor available to a canine. In fact, odor availability depends no...
Explosives detection by military working dogs: Olfactory generalization from components to mixtures
The training of scent detection dogs using samples of explosives or their chemical precursors is a well-established and documented practice. However an area of canine odor detection that remains under-studied regards a trained dog's perception of an explosive odor when more than one odorant is combined to produce a mixture. The first objective of our study was to determine whether training adult Labrador Retrievers (n = 20) to detect the scent of chemically pure potassium chlorate (PC) was sufficient to produce generalization to PCbased explosive mixtures that contained a novel component. We found that the majority of dogs (87%) trained with pure PC alone did not correctly signal the presence of one or more of four PC-based explosive mixtures. Our second objective was to determine whether training dogs using the separated components found in the PC-based explosives would subsequently enhance detection. Dogs were then trained using a novel static odor delivery device that safely segregated the PC and non-PC components and presented a merged odor to the dog. A statistically significant improvement in percentage of dogs detecting PC-based mixtures after training with the separated components compared to training with PC alone was seen with Mixture 1 (27-100%, P < 0.0001), Mixture 2 (40-81%, P = 0.0229), Mixture 3 (38-94%, P = 0.0004), and Mixture 4 (69-100%, P < 0.005). The results of this study highlight the potential limitations of dogs trained to detect a single odor to then recognize the odor when mixed with other substances. The odor delivery device developed for this study represents an important and effective training option that may reduce the need for using a final PC explosive mixture in canine training.
Journal of Forensic Sciences, 2023
While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel–oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid‐phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC i...
Selecting Dogs for Explosives Detection: Behavioral Characteristics
Frontiers in Veterinary Science, 2020
Detection dogs are widely considered the most effective and adaptive method for explosives detection. Increases in emerging sophisticated threats are accelerating the demand for highly capable explosives detection, causing a strain on available supplies of quality canines worldwide. These strains are further compounded by rigorous behavioral standards required to meet mission-specific capabilities, leading to high rates of dogs disqualified from training or deployment. Ample research has explored the behavioral characteristics important for assistance, guide, and other traditional working roles, while those corresponding to more specialized tasks such as detection of explosives are not as well-understood. In this review we aim to identify the behavioral characteristics important for operational tasks of explosives detection dogs, contrasting with that of other working roles and highlighting key differences between explosives and other types of detection dogs. Further, we review the available research on methods for assessing and selecting candidate detection dogs and make recommendations for future directions and applications to the industry. Improvements and standardization in assessment technology allowing for the identification and enhancement of behavioral characteristics will be key to advancing canine detection technology in general.
“Fooling fido”—chemical and behavioral studies of pseudo-explosive canine training aids
Analytical and Bioanalytical Chemistry, 2014
Genuine explosive materials are traditionally employed in the training and testing of explosive-detecting canines so that they will respond reliably to these substances. However, challenges arising from the acquisition, storage, handling, and transportation of explosives have given rise to the development of "pseudo-explosive" training aids. These products attempt to emulate the odor of real explosives while remaining inert. Therefore, a canine trained on a pseudoexplosive should respond to its real-life analog. Similarly, a canine trained on an actual explosive should respond to the pseudo-explosive as if it was real. This research tested those assumptions with a focus on three explosives: single-base smokeless powder, 2,4,6-trinitrotoluene (TNT), and a RDXbased plastic explosive (Composition C-4). Using gas chromatography-mass spectrometry with solid phase microextraction as a pre-concentration technique, we determined that the volatile compounds given off by pseudoexplosive products consisted of various solvents, known additives from explosive formulations, and common impurities present in authentic explosives. For example, simulated smokeless powders emitted terpenes, 2,4-dinitrotoluene, diphenylamine, and ethyl centralite. Simulated TNT products emitted 2,4-and 2,6-dinitrotoluene. Simulated C-4 products emitted cyclohexanone, 2-et hyl-1-hexanol, and dimethyldinitrobutane. We also conducted tests to determine whether canines trained on pseudo-explosives are capable of alerting to genuine explosives and vice versa. The results show that canines trained on pseudo-explosives performed poorly at detecting all but the pseudo-explosives they are trained on. Similarly, canines trained on actual explosives performed poorly at detecting all but the actual explosives on which they were trained.
Analytical and Bioanalytical Chemistry, 2003
This paper describes the use of headspace solidphase microextraction (SPME) combined with gas chromatography to identify the signature odors that law enforcementcertified detector dogs alert to when searching for drugs, explosives, and humans. Background information is provided on the many types of detector dog available and specific samples highlighted in this paper are the drugs cocaine and 3,4methylenedioxy-N-methylamphetamine (MDMA or Ecstasy), the explosives TNT and C4, and human remains. Studies include the analysis and identification of the headspace "fingerprint" of a variety of samples, followed by completion of double-blind dog trials of the individual components in an attempt to isolate and understand the target compounds that dogs alert to. SPME-GC/MS has been demonstrated to have a unique capability for the extraction of volatiles from the headspace of forensic specimens including drugs and explosives and shows great potential to aid in the investigation and understanding of the complicated process of canine odor detection. Major variables evaluated for the headspace SPME included fiber chemistry and a variety of sampling times ranging from several hours to several seconds and the resultant effect on ratios of isolated volatile components. For the drug odor studies, the CW/DVB and PDMS SPME fibers proved to be the optimal fiber types. For explosives, the results demonstrated that the best fibers in field and laboratory applications were PDMS and CW/DVB, respectively. Gas chromatography with electron capture detector (GC/ECD) and mass spectrometry (GC/MS) was better for analysis of nitromethane and TNT odors, and C-4 odors, respectively. Field studies with detector dogs have demonstrated possible candidates for new pseudo scents as well as the potential use of controlled permeation devices as non-hazardous training aids providing consistent permeation of target odors.