Human remains detection (HRD) canines are a crucial tool for victim recovery efforts around the globe. These biological sensors are trained to locate human remains in the form of whole bodies, body parts, blood, bone, tissue, or decomposition fluids. During the complex process of decomposition, different microorganisms, including bacteria and fungi, play a role in tissue breakdown within the body. This breakdown releases various liquids, gases, and chemical compounds, yielding the release of volatile organic compounds (VOCs). There has been a renaissance of research studies to identify types and amounts of distinctive compounds under different environmental conditions and decomposition stages from both human and animal models. However, a current gap in the literature is understanding how this decomposition odor profile affects canine training when it relates to routine training aid use. Hence, it was the intent of this study to collect samples at different stages of decomposition and monitor the stability of the instrumental odor profile across a period of six weeks under refrigerated conditions. Three animal models (<i>Sus scrofa</i>) were laid out on a field and allowed to reach a targeted stage of decomposition (fresh, advanced decay, dry/skeletal). Once the targeted stage had been reached, tissue samples were collected, stored, and analyzed via Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS). The headspace odor concentration of each simulated-training aid was monitored over a 6-week period to evaluate compound frequency and occurrence. Replicate samples were opened/closed each week to simulate routine training aid handling. Additionally, a set of triplicate samples for each week were collected and analyzed once throughout the 6-week period. The results depicted a difference in chemical compound abundance within the different stages of decomposition, as well as the different environmental seasons. Fluctuation was observed throughout the 6-week period, however the tissue samples that were not opened/closed on a weekly basis depicted slightly higher compound abundance. Instrumental analysis can aid to understand decomposition odor fate under extended refrigerated storage conditions. This study can provide foundational guidelines as to proper storage and shelf life of decomposition materials routinely utilized as target odor sources for cadaver dog teams.

Using chromatographic methods to evaluate the stability of decomposition odor profiles under freezing storage conditions

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