Exploring the volatile organic compounds of decomposition to solve crimes, locate disaster victims, and combat wildlife trafficking
In a world where climate change and global conflicts are increasing the frequency of mass disasters, the ability to locate victims quickly and accurately has never been more critical. While most people avoid the subject of death, one scientist has dedicated her career to studying what happens after we die—and how that knowledge can help solve crimes and bring closure to grieving families.
Dr. Maiken Ueland, a forensic chemist at the University of Technology Sydney, examines the volatile organic compounds released during human decomposition to develop cutting-edge tools for detecting human remains.
Her work bridges the gap between macroscopic forensic investigation and microscopic chemical analysis, creating new possibilities for law enforcement and disaster response teams around the world 1 .
Combining chemistry, biology, and forensic science to solve complex problems
Developing technologies to locate missing persons where traditional methods fail
When human bodies decompose, they release a complex cocktail of chemicals known as volatile organic compounds (VOCs). These carbon-based chemicals easily evaporate at room temperature, creating the distinctive scent of decomposition that trained cadaver dogs can detect. Ueland's research focuses on identifying the specific VOCs that serve as reliable biomarkers for human remains, distinguishing them from animal decomposition or other organic decay processes 1 .
The composition of these VOCs changes over time, creating a chemical timeline that can help investigators determine how long someone has been deceased. This process is influenced by numerous factors including temperature, humidity, insect activity, soil composition, and even the individual's unique biology.
"Factors such as people's fat content, internal microbes, or what they ate when they were alive influence the decomposition process," Ueland explains, highlighting the complexity of forensic chemistry 1 .
Ueland's work has significant practical applications in multiple areas:
Locating buried or hidden human remains more efficiently
Accelerating victim recovery in mass casualty incidents
Providing scientific methods for establishing postmortem interval
Improving the accuracy of cadaver dog training protocols
"On television it looks super easy: they just go, 'Oh, this person's been dead for 4 weeks and 3 days, and they died at 5:22 a.m.' But actually, it's a very challenging question to answer," she notes 1 .
Ueland serves as deputy director of the Australian Facility for Taphonomic Experimental Research (AFTER), the only human taphonomy facility in the Southern Hemisphere. Established in 2016, AFTER uses donated human cadavers to study decomposition processes in Australia's unique climate and ecosystem. This research is vital because decomposition rates and patterns vary significantly across different environments 1 .
Before AFTER opened, forensic investigators in Australia had to rely on data from facilities in the United States, where climate conditions and insect populations differ substantially.
"We couldn't just take data from the US facilities and apply it to casework here," Ueland explains 1 .
The Australian climate often leads to mummified tissue that persists much longer than in cooler, less arid environments.
"A body that appears like it's been there for 4 months, according to US data, might actually have been there a year," she notes 1 .
The work conducted at AFTER follows strict ethical guidelines regarding the use of donated remains. All research is conducted with respect for the donors who have generously contributed their bodies to advance forensic science. This ethical framework ensures that the data collected can be used confidently by law enforcement and judicial systems without concerns about its origins 1 .
One of Ueland's most significant research initiatives involved identifying the key volatile organic compounds that distinguish human decomposition from other types of organic decay. This experiment required meticulous planning and advanced analytical techniques to ensure reliable, reproducible results 1 .
The study employed a comparative experimental design using donated human remains alongside animal models (primarily pigs, which have traditionally been used as human analogs in decomposition research). The researchers placed remains in various environments and monitored VOC release over time to document the complete decomposition process 1 .
The team used static headspace sampling with comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). This advanced analytical approach allowed them to separate and identify thousands of chemical compounds in the complex decomposition odor profile. Samples were collected at regular intervals over several months to capture the changing VOC profile throughout decomposition 1 3 .
Researchers placed remains in designated research areas at the AFTER facility, using specialized adsorption traps to collect VOCs at regular intervals. These traps captured chemicals released into the air surrounding the remains, providing a complete profile of the decomposition volatiles 1 .
The massive datasets generated by GC×GC-TOFMS were processed using multivariate statistical analysis to identify patterns and key biomarkers. Machine learning algorithms helped distinguish human-specific VOCs from those common to all decomposition processes 1 .
The experiment successfully identified key chemical biomarkers that differentiate human decomposition from animal decomposition. Among the most significant findings was the importance of dimethyl trisulfide (Ueland's favorite molecule) as a key indicator of human remains. The research also revealed that the ratio of specific compounds rather than single chemicals provides the most reliable identification 1 .
Perhaps most significantly, the research demonstrated that pigs—long used as proxies for human decomposition in forensic research—produce substantially different VOC profiles. This finding has crucial implications for past research that relied on porcine models and highlights the necessity of human-based research in this field 1 .
| Compound Class | Specific Compounds | Decomposition Stage | Significance |
|---|---|---|---|
| Sulfides | Dimethyl trisulfide, dimethyl disulfide | Early to middle | Most reliable human biomarkers |
| Nitrogen-containing compounds | Putrescine, cadaverine | Middle | Common across species but ratios differ |
| Alcohols | Pentanol, hexanol | Early | More prevalent in human decomposition |
| Acids | Butanoic acid, pentanoic acid | Middle to late | Persist in soil environment |
Table 1: Key VOC Biomarkers in Human Decomposition
Forensic chemistry requires sophisticated equipment and specialized materials to obtain reliable results. The following tables highlight key components of Ueland's research toolkit 1 3 .
| Equipment | Function | Application in Forensic Chemistry |
|---|---|---|
| Comprehensive Two-Dimensional Gas Chromatography (GC×GC) | Separates complex chemical mixtures | Analyzes VOC profiles from decomposition |
| Time-of-Flight Mass Spectrometry (TOFMS) | Identifies chemicals based on mass-to-charge ratio | Provides precise compound identification |
| Electronic Nose (E-nose) | Portable field detection device | Detects decomposition VOCs in disaster scenarios |
| Sorption Tubes | Collects volatile compounds from air | Field sampling of decomposition odors |
Table 2: Analytical Equipment Used in VOC Research
| Reagent/Material | Function | Importance |
|---|---|---|
| Tenax TA adsorption tubes | VOC collection | Captures broad range of volatile compounds |
| Internal standards (deuterated compounds) | Quantitative calibration | Allows precise measurement of VOC concentrations |
| Calibration gas standards | Instrument calibration | Ensures analytical accuracy |
| Reference compounds | Compound identification | Verifies presence of specific biomarkers |
Table 3: Key Chemical Reagents and Materials
Ueland's research has particularly important applications in mass disaster response.
"Mass disasters are increasing worldwide due to climate change and an increased threat of terrorism," she notes. "You want to make sure that you are ready before the disaster strikes and not just scrambling afterwards" 1 .
Her work on portable electronic "noses" that can detect decomposition VOCs could revolutionize how first responders locate victims in rubble after earthquakes, hurricanes, or terrorist attacks. These devices could complement or even eventually replace cadaver dogs, working in environments too dangerous for human-dog teams and operating for extended periods without fatigue 1 .
In an unexpected cross-application, Ueland has adapted her human detection methods to combat illegal wildlife trafficking.
"I'm applying the same principles we rely on for human detection to develop methods that can detect illegal wildlife trafficking, which is a massive biosecurity risk because of the potential for infectious diseases to transfer from these animals to native plants and animals, including people," she explains 1 .
This innovative approach demonstrates how forensic chemistry techniques can be adapted to address multiple global challenges beyond their original applications. By detecting the odor signatures of protected species or their products (such as ivory or tortoiseshell), authorities can more effectively intercept illegal shipments and prosecute traffickers 3 .
Despite significant advances, the field of decomposition VOC analysis faces several challenges:
Ueland is also working to develop more objective measurement techniques to reduce the subjectivity that plagues current forensic methods.
"A lot of methods are very subjective, relying on visual cues that people might interpret slightly differently, so we're looking for more objective ways of measuring that decomposition trajectory," she notes 1 .
The future of forensic chemistry looks promising, with several exciting developments on the horizon:
Creating smaller, more sensitive detection devices for field use
Enhancing machine learning approaches for faster, more accurate VOC identification
Developing consistent methodologies for forensic investigations worldwide
Establishing global networks of taphonomy facilities to study decomposition across diverse environments
"We've had some good success, with it being able to pick up human remains hidden underneath debris and rubble in a simulated disaster," she reports 1 .
Maiken Ueland's work challenges us to reconsider our relationship with death and decomposition. Rather than something to be avoided or feared, she sees decomposition as a natural process that can provide crucial information for the living. Her research combines scientific curiosity with practical compassion, developing tools that can bring closure to families and justice to victims of crimes and disasters 1 .
From her childhood fascination with crime novels to her pioneering work at the AFTER facility, Ueland's career demonstrates how interdisciplinary approaches can solve complex problems. By blending chemistry, biology, engineering, and forensic science, she and her colleagues are creating a new future for forensic investigation—one where technology enhances our ability to address some of humanity's most challenging situations 1 .
As climate change and global conflicts continue to threaten mass disasters, Ueland's research becomes increasingly vital. The electronic noses and detection methods she's developing may soon become standard equipment for first responders worldwide, saving precious time in recovery efforts and potentially saving lives in the process. In the delicate interface between life and death, Ueland's work proves that even in decomposition, there is valuable information waiting to be discovered by those with the knowledge and tools to find it 1 .