Identifying the transition from ante-mortem to post-mortem odor in cadavers in an outdoor environment.

Establishing the volatile profile of pig carcasses as analogues for human decomposition during the early postmortem period

Characterization of the volatile organic compounds present in the headspace of decomposing animal remains, and compared with human remains

Cadaver‐detection dogs (CDDs) are an essential tool for the search and detection of human remains. In order to enhance their search capability, CDDs are regularly trained on natural and synthetic training aids. The odor profile of these training aids comprises a range of volatile organic compounds (VOCs) which is intended to resemble those produced by a decomposing body. It is currently unknown if detector dogs respond to the same stimuli and whether it is a specific VOC or a suite of decomposition‐related VOCs as their target odor. This review summarizes the VOCs that have been detected in various CDD training aids such as blood, human remains, decomposition fluid, soil, buried remains, textile, and synthetic formulations. Additionally, it discusses the reported capability of CDDs to respond to each of these training aids. The purpose of this review is to understand the variability of VOCs in CDD training aids and the response of CDDs to this wide range of compounds. Additionally, this review attempts to determine if there is a specific training aid to which CDDs respond preferentially. Such a review will assist to establish better practices for CDD training since no standardized practices exist globally.This article is categorized under: Crime Scene Investigation > Special Situations and Investigations Forensic Anthropology > Taphonomic Changes and the Environment Forensic Medicine > Death Scene Investigation

Complex processes of decomposition produce a variety of chemicals as soft tissues, and their component parts are broken down. Among others, these decomposition byproducts include volatile organic compounds (VOCs) responsible for the odor of decomposition. Human remains detection (HRD) canines utilize this odor signature to locate human remains during police investigations and recovery missions in the event of a mass disaster. Currently, it is unknown what compounds or combinations of compounds are recognized by the HRD canines. Furthermore, a comprehensive decomposition VOC profile remains elusive. This is likely due to difficulties associated with the nontarget analysis of complex samples. In this study, cadaveric VOCs were collected from the decomposition headspace of pig carcasses and were further analyzed using thermal desorption coupled to comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (TD-GC × GC-TOFMS). Along with an advanced data handling methodology, this approach allowed for enhanced characterization of these complex samples. The additional peak capacity of GC × GC, the spectral deconvolution algorithms applied to unskewed mass spectral data, and the use of a robust data mining strategy generated a characteristic profile of decomposition VOCs across the various stages of soft-tissue decomposition. The profile was comprised of numerous chemical families, particularly alcohols, carboxylic acids, aromatics, and sulfides. Characteristic compounds identified in this study, e.g., 1-butanol, 1-octen-3-ol, 2-and 3-methyl butanoic acid, hexanoic acid, octanal, indole, phenol, benzaldehyde, dimethyl disulfide, and trisulfide, are potential target compounds of decomposition odor. This approach will facilitate the comparison of complex odor profiles and produce a comprehensive VOC profile for decomposition.

Human remains detection (HRD) dogs are vital tools in forensic science and disaster response, but their training is limited by the restricted availability of human material. Synthetic odorants such as Sigma Pseudo™ formulations provide safer, standardized alternatives, yet current products reproduce only a fraction of the volatile organic compound (VOC) profile of decomposition. In particular, sulfur-containing volatiles, which are highly odor-active and consistently present in human remains, are often missing, reducing biological fidelity. Here, we integrate analytical chemistry with canine olfactory genetics and molecular biology to explain these limitations. Dogs possess one of the largest olfactory receptor (OR) repertoires among mammals, with high allelic diversity and specialized trace amine-associated receptors (TAARs) tuned to cadaveric amines. Together with olfactory binding proteins (OBPs) and ciliary signal transduction cascades, these molecular mechanisms highlight why incomplete VOC mixtures may fail to activate the full receptor network required for reliable odor imprinting. We propose the “sulfur gap hypothesis” and suggest hybrid training strategies combining improved synthetics with ethically sourced biological samples to enhance HRD dog performance.

Airborne volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) are commonly quantitated by collecting the analytes on solid sorbent tubes or passive air samplers, followed by solvent extraction and instrumental analysis, or by grab bag/canister measurements. We report herein a user-friendly sampling method by breathing through polyurethane foam (PUF) face masks to collect airborne VOCs and SVOCs for chemical analysis. Specifically, dibasic esters, phthalate esters, polycyclic aromatic hydrocarbons, linalool, and nicotine trapped on PUF masks were quantitated by gas chromatography-mass spectrometry analysis as model VOCs and SVOCs. Results showed that the amount of these model VOCs and SVOCs trapped on PUF masks is proportional to the exposure duration. After cross-validation by parallel sampling using XAD-2 packed sorbent tubes, the method was used to quantitate VOCs and SVOCs in a variety of indoor and outdoor environments with varying air concentrations of analytes, temperature, humidity, and wind speed. Because air pollution is considered a major cause of many human diseases and premature deaths and the developed PUF mask sampling method showed high trapping efficiencies for both VOCs and SVOCs, it is believed that the developed sampling method will find wide application in assessing air pollution-associated disease risks with possible extension to more classes of VOCs and SVOCs when coupled with suitable instrumental detection methods.

Cadaver detection dogs (CDDs) are trained to locate human remains and/or objects associated with human remains. This is possible due to their extraordinary olfactory capabilities compared to those of humans. To reinforce this capability, CDDs must be trained and regularly exposed to the target odor in the form of training aids which include—chemical formulations, animal remains, and/or human remains. Currently, the Ontario Provincial Police (OPP) use amputated limbs/feet from consented surgeries performed on diabetic patients as cadaver detection dog training aids. There is limited knowledge about the volatile organic compound (VOC) composition of these training aids and their appropriateness as an alternative to human remains for CDD training purposes, which formed the aim of the current study. VOCs were collected from amputated lower limbs/feet repeatedly using thermal desorption (TD) tubes and analyzed with comprehensive two-dimensional gas chromatography—time-of-flight mass spectrometry (GC×GC-TOFMS). The response of cadaver detection dogs to these training aids was also recorded to understand their alert in the context of the detected VOCs. VOC classes including acids, alcohols, aldehydes, ketones, ester and analogues, ethers, aliphatic, cyclics, sulfur-containing, nitrogen-containing, and halogen-containing VOCs were identified. Of these classes, cyclic VOCs were most abundant followed by nitrogen-containing VOCs while ethers were the least abundant. The most prominent VOCs identified in amputated limbs/feet were decomposition related however, one VOC—sevoflurane, originated from anaesthesia during the surgeries. It was determined that the VOC profile of aged and relatively recent training aids were variable. The aged training aids sampled over time had less variability (compared to more recent training aids). Additionally, the VOC profiles of samples was not found variable owing to the storage conditions—room temperature, refrigerator or freezer. Overall, a 98.4% detection rate was observed for amputated limbs/feet used as CDD training aids and the presence of non-decomposition related VOCs such as sevoflurane did not appear to impact the CDDs’ detection capability. This study highlights that the presence of decomposition VOCs in amputated limbs/feet and their high detection rate by CDDs validates their use as alternative CDD training aids.

Profiling the decomposition odour at the grave surface before and after probing

Cadaver-detection dogs are trained to locate victim remains; however, their training is challenging owing to limited access to human remains. Animal analogues, such as pigs, are typically used as alternative training aids. This project aimed to compare the visual decomposition and volatile organic compound (VOC) profile of human and pig remains in an Australian environment, to determine the suitability of pig remains as human odour analogues for cadaver-detection dog training. Four human cadavers and four pig carcasses were placed in an outdoor environment at the Australian Facility for Taphonomic Experimental Research (AFTER) across two seasons. Decomposition was monitored progressively in summer and winter. VOCs were collected onto sorbent tubes and analysed using comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry. Visual observations highlighted the differences in decomposition rates, with pig remains progressing through all stages of decomposition, and human remains undergoing differential decomposition and mummification. Chemical and statistical analysis highlighted variations in the composition and abundance of VOCs over time between the odour profiles. This study concluded that the visual decomposition and VOC profile of pig and human remains was dissimilar. However, in cooler conditions the results from each species became more comparable, especially during the early stages of decomposition.

The objective of this study is to characterize indoor and outdoor levels of volatile organic compounds (VOCs) and formaldehyde (HCHO) and identify indoor emission sources in thirty elderly care centers (ECCs) located in the Seoul metropolitan city and Gyeonggi province in Korea. Air monitoring samples from indoor and outdoor environments were collected from January to December in 2007. Statistical analyses of indoor and outdoor VOCs and HCHO levels in three rooms (a bedroom, living, and dining rooms) of each ECC were performed, and these were compared to identify environmental factors associated with an increase of indoor pollution levels. Total volatile organic compounds (TVOC) levels were significantly (p<0.05) different between indoor (230.7±1.7 μg/m3) and outdoor (137.8±1.9 μg/m3) environments, with an I/O ratio of 1.67. The indoor HCHO level (20.1±1.6 μg/m3) was significantly (p<0.05) higher than the outdoor level (8.1±1.9 μg/m3), with an I/O ratio of 2.48. Indoor VOCs and HCHO levels in the bedrooms were significantly (p<0.05) higher than those in the living and dining rooms. Furthermore, indoor levels of VOCs and HCHO at ECCs were significantly (p<0.05) different depending on environmental factors such as the use of carpet, paint, and wooden furniture. In multiple regression analysis, indoor VOCs and HCHO levels at ECCs were significantly (p<0.05) correlated with two micro-environmental factors: the use of carpet and paint. This study confirmed that indoor VOCs and HCHO levels were significantly higher than those in outdoor environments. These air pollutants were mainly emitted from indoor sources, such as carpet, paint, and construction materials at the ECCs in Korea.

The study of chemical bioactivity in the rhizosphere has recently broadened to include microbial metabolites, and their roles in niche construction and competition via growth promotion, growth inhibition, and toxicity. Several prior studies have identified bacteria that produce volatile organic compounds (VOCs) with antifungal activities, indicating their potential use as biocontrol organisms to suppress phytopathogenic fungi and reduce agricultural losses. We sought to expand the roster of soil bacteria with known antifungal VOCs by testing bacterial isolates from wild and cultivated cranberry bog soils for VOCs that inhibit the growth of four common fungal and oomycete plant pathogens, and Trichoderma sp. Twenty one of the screened isolates inhibited the growth of at least one fungus by the production of VOCs, and isolates of Chromobacterium vaccinii had broad antifungal VOC activity, with growth inhibition over 90% for some fungi. Fungi exposed to C. vaccinii VOCs had extensive morphological abnormalities such as swollen hyphal cells, vacuolar depositions, and cell wall alterations. Quorum-insensitive cviR− mutants of C. vaccinii were significantly less fungistatic, indicating a role for quorum regulation in the production of antifungal VOCs. We collected and characterized VOCs from co-cultivation assays of Phoma sp. exposed to wild-type C. vaccinii MWU328, and its cviR− mutant using stir bar sorptive extraction and comprehensive two-dimensional gas chromatography—time-of-flight mass spectrometry (SBSE-GC × GC-TOFMS). We detected 53 VOCs that differ significantly in abundance between microbial cultures and media controls, including four candidate quorum-regulated fungistatic VOCs produced by C. vaccinii. Importantly, the metabolomes of the bacterial-fungal co-cultures were not the sum of the monoculture VOCs, an emergent property of their VOC-mediated interactions. These data suggest semiochemical feedback loops between microbes that have co-evolved for sensing and responding to exogenous VOCs.

Study question Can the viscosity of mineral oils used in embryo culture systems influence their protective effect against the embryotoxic impact of volatile organic compounds (VOCs)? Summary answer Embryonic developmental outcomes in sub-optimal environmental conditions with high VOC concentrations are protected more efficiently by high-viscosity mineral oils compared to low-viscosity oils. What is known already VOCs are gaseous emissions of organic compounds (including aldehydes [HCHO], alcohols, and hydrocarbons) commonly found in indoor and outdoor environments. Two of the most widely used VOCs are isopropyl-alcohol (solvent frequently used in cleaning products) and paraformaldehyde (a commonly used fixing agent). Whilst their embryotoxic effect is known, their presence in embryo culture systems is common and well documented. Mineral oil acts as a protective layer between the VOCs in the environment and the embryos in culture, but the extent to which the viscosity of the used mineral oils plays a role in its protective effect against VOCs remains unclear. Study design, size, duration Two isopropyl-alcohol wipes or 250µL of 4% paraformaldehyde were used as VOC sources. For each positive test, three dishes with 5mL of oil (high, medium or low viscosity) and culture medium droplets were placed under a glass bell jar with the VOC source nearby for 16h. For each oil, a negative control (without VOC exposure) was prepared in parallel. After incubation, dishes were equilibrated for 24h at 6%CO2 and 7%O2 before starting the mouse-embryo-assays. Participants/materials, setting, methods Oils with 102.1cP, 43.1cP and 22.3cP at 30oC were selected as high (HVO), medium (MVO) and low viscosity (LVO), respectively. Experiments were performed in triplicate with 21 freshly collected mouse zygotes each (n = 846). Cleavage rate was assessed after 24h, and expanded blastocyst formation rate (EBFR) was determined at 96 and 120hours. Resulting blastocysts were fixed and stained for cell counting, and lab VOC/HCHO levels were monitored throughout. Statistical analysis was performed using Fisher’s or Kruskal-Wallis. Main results and the role of chance In the experiments with isopropyl-alcohol (&amp;gt;5 ppm), no differences in cleavage rate were observed across the experimental groups (p &amp;gt; 0.05). The EBFR was heavily reduced by VOCs in the MVO and LVO groups (46.0% and 36.5%, respectively) compared to their non-exposed controls (95.2% and 98.4%; p &amp;lt; 0.0001); by contrast, the HVO was able to avoid this reduction (98.4% EBFR in the VOC-exposed group and 100% in the non-exposed control; p = 1). Mean cell counts indicated a decrease in blastocyst quality in the VOCs-exposed groups compared to their corresponding controls with all three oils: 167.90 (±37.47 SD) vs. 187.95 (±39.51 SD) with HVO (p = 0.0361); 126.59 (±33.99 SD) vs. 188.47 (±36.35 SD) with MVO (p &amp;lt; 0.0001); 101.57 (±38.73 SD) vs. 179.45 (±35.16 SD) with LVO (p &amp;lt; 0.0001). Exposure to paraformaldehyde (&amp;gt;5 ppm) resulted much more embryo-toxic, already producing significant differences in cleavage rate on day 2 in all oil groups (23.8% HVO, 0% MVO, 0% LVO) compared to their corresponding non-exposed controls (100%, 100% and 96.83%, respectively; p &amp;lt; 0.0001). The EBFR was 0% in all paraformaldehyde-exposed groups, while in all negative controls more than 90% of the embryos reached this stage (p &amp;lt; 0.0001). Limitations, reasons for caution Further studies are needed to assess the effects of different VOC types and concentrations on embryo development, as their impact may vary. Additional replicates are necessary to enhance the robustness of the findings. Moreover, the results in mice may not fully translate to human embryos. Wider implications of the findings This study suggests that high-viscosity mineral oils confer higher protection to embryos against VOC exposure, optimizing embryo culture conditions. It also offers insights towards the development of sensitive mouse-embryo-assays to assess VOC effects in culture systems, highlighting the importance of mineral oil viscosity to improve success rates in fertility treatments. Trial registration number No

As far as scent is concerned, little technology has been developed In the field of search and rescue (SAR) operations. In this paper, the use of electronic noses (e-noses) in SAR, more specifically search operation, is discussed. The e-nose consists of an array of TGS tin-oxide gas sensors, whose signals are digitized, and then fed into an artificial neural network (ANN) for odor classification. Odor samples are collected from odiferous items such as egg, prawn, fish, cigarette, urine, feces, sweat, saliva, garlic, and onion. The gas sensing system developed is able to detect and identify volatile organic compounds (VOCs) from known single sources. However, VOCs from known multiple sources were not conclusively identified.

Objectives: Volatile organic compounds (VOCs) are a type of pollutant that causes health risks and can be present in both indoor and outdoor environments. VOCs originate mainly from solvents and chemicals used at home or in offices and also from vehicle emissions. The current research work was aimed at the detection and quantification of VOCs indoor and outdoor at Sri Ramachandra Faculty of Pharmacy, Sri Ramachandra Institute of Higher Education and Research (DU), Porur, Chennai, Tamil Nadu, India. Material and Methods: Air was drawn through an adsorbent tube with a pump at a steady flow rate (100 mL min-1) for an hour to gather samples using the active sampling approach. Thermal desorption in combination with a gas chromatography (GC) analyzer was used to estimate the levels of hazardous VOCs, namely benzene, toluene, ethylbenzene, m-xylene, p-xylene, and o-xylene (BTEX) compounds. Results: VOCs were analyzed using the GC-mass spectroscopy technique. The finding shows the levels of BTEX as benzene (0.05–0.11 μg/m3), toluene (0.44–1.27 μg/m3), ethylbenzene (0.012–0.03 μg/m3), m-xylene (0.009–0.027 μg/m3), p-xylene (0.007–0.025 μg/m3), and o-xylene (0.003–0.019 μg/m3) compounds. Conclusion: The BTEX levels were observed to be well below the maximum acceptable limit. VOC emissions can be reduced by making process changes or by installing air pollution control equipment.

Volatile organic compounds (VOCs) emitted by seeds serve as promising biomarkers for assessing seed vigor, viability, and deterioration during storage. This review synthesizes current knowledge on the types and chemical classes of VOCs released by seeds, factors affecting their emission, and methods for their collection and analysis. VOCs indicate seed aging, with increased emissions of alcohols, aldehydes, and ketones associated with deterioration processes like lipid peroxidation. Volatile organic compounds (VOCs) associated with seed deterioration include alcohols like ethanol, which can indicate fermentation, aldehydes such as hexanal, which is linked to lipid oxidation, and ketones like 2-heptanone, which can result from microbial activity and contribute to off-flavors and rancidity. The quantity and composition of VOCs correlate with the extent of seed deterioration, potentially offering a rapid, non-destructive alternative to traditional germination tests for evaluating seed quality. VOCs also mediate interactions between seeds and microorganisms, influencing germination and stress responses. Different research findings regarding volatile organic compounds (VOCs) in seeds indicate their potential as indicators of seed quality, which could lead to improved seed management strategies. By utilizing VOC profiling, farmers can make informed decisions on seed selection and treatment, ultimately enhancing crop yield and resilience in agricultural practices. While VOC analysis shows promise for integration into seed quality testing, challenges remain in standardizing protocols and identifying robust markers across different seed types, species and storage conditions. Advances in VOC research may ultimately lead to novel solutions for improving seed and crop productivity. Future research directions in VOC analysis for seed quality testing should focus on standardizing VOC profiles across diverse seed species, integrating VOC analysis with precision agriculture technologies, exploring environmental influences on VOC emissions, developing non-invasive testing methods, conducting longitudinal studies on seed storage, applying VOCs in breeding programs, and establishing links between VOC emissions and disease resistance.