Investigation on human cadaveric VOC by TD-GCxGC-TOFMS

The study of the ‘smell of death’ is a challenging task. Analytical chemists who try to understand human decomposition are facing very complex mixtures of analytes present at various levels. For the last few decades, investigations have been conducted to better learn the process of body decomposition by mean of the measurement of the Volatile Organic Compounds (VOCs) released during decay1. However, the chemical profile of the decomposition odor is still far from being elucidated. Indeed, the complexity of the VOC mixtures makes this profiling difficult to be carried out by a classical gas chromatography mass spectrometry (GC-MS) approach.
In previous studies, we developed direct-sampling based approaches for cadaveric VOC analysis from grave soils and decaying bodies by mean of thermal desorption (TD) coupled to comprehensive two-dimensional GC coupled to time-of-flight MS (GC×GC-TOFMS)2,3,4. They were based on the use of human analogs (Sus domesticus L. carcasses).
For the present study, we investigated the VOC profile of early stage decomposition of human bodies. We analyzed samples collected during different trials organized during different seasons in a body farm located in Texas. Samples included environmental controls, pig carcasses, and human bodies (protected or not from scavenger insects). The data processing was performed in the light of identifying possible seasonal and species variations. Both peak capacity enhancement and spectral deconvolution helped to characterize VOC mixtures and improve comparisons of profiles.
Acknowledgements: Human samples were collected during the project “Development and validation of standard operating procedures for measuring microbial populations for estimating a post-mortem interval” Grant Award No. 2010-DN-BX-K243. The authors of that grant are acknowledged for giving us the opportunity to access cadavers for sampling.

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2. Brasseur C. et al. Comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry for the forensic study of cadaveric volatile organic compounds released in soil by buried decaying pig carcasses. J Chromatogr A (2012) 1255, 163–170.
3. Dekeirsschieter, J. et al. Enhanced characterization of the smell of death by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOFMS). PLoS ONE (2012) 7, e39005.
4. Stadler, S. Characterization of volatile organic compounds from human analogue decomposition using thermal desorption coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. Anal Chem (2013) 85, 998–1005.