Development and validation of a new TD-GC/MS method and its applicability in the search for human and animal decomposition products

Abstract

Differentiation between human and animal remains by means of analysis of volatile compounds released during decomposition is impossible since no volatile marker(s) specific for human decomposition has been established today. Hence, the identification of such a marker for human decomposition would represent great progression for the discovery of buried cadavers by analytical techniques. Cadaver dogs can be trained more efficiently, the understanding of forensic entomology can be enhanced, and the development of a portable detection device may be within reach. This study describes the development and validation of a new analytical method that can be applied in the search of such (a) specific marker(s). Sampling of the volatile compounds released by decomposing animal and human remains was performed both in a laboratory environment and outdoors by adsorption on sorbent tubes. Different coatings and several sampling parameters were investigated. Next, the volatile compounds were analyzed and identified by a thermal desorber combined with gas chromatography coupled to mass spectrometry (TD-GC/MS). Different GC columns were tested. Finally, the analytical method was validated using a standard mixture of nine representative compounds.

A Comparison of One-Dimensional and Comprehensive Two-Dimensional Gas Chromatography for Decomposition Odour Profiling Using Inter-Year Replicate Field Trials

“…A similar range of chemical classes was also identified in the VOC profile of human remains recovered from the Mediterranean Sea, with over 80 VOCs detected using TD-GC-qMS [8]. Following these pioneering studies, other investigations of the VOC profile of human cadavers [9], human remains [5,[10][11][12], select human tissues [13,14] and animal remains [12,15,16], have reported varying numbers of decomposition compounds, ranging from 30 to 135 VOCs. All of these studies were carried out using GCqMS; however, sample collection techniques varied and included sorbent tubes [6-9, 11, 12, 16], diffusive samplers [10], and solid phase microextraction (SPME) [5,[13][14][15], which may account for some of the variation in the number of VOCs reported.…”

Reducing variation in decomposition odour profiling using comprehensive two-dimensional gas chromatography

“…Numerous publications have resulted from the investigation of the decomposition VOC profile . Initial studies examined the chemical classes and trends that existed over the various stages of decomposition.…”

“…Variation introduced by matrix and VOC collection techniques has recently been investigated . Sorbent tubes are now widely used to collect decomposition VOCs due to analytical advantages such as sample pre‐concentration, lack of chromatographic artefacts, stability and ease of use in the field . While there is a move towards collection‐method standardisation, variation in instrumentation usage has yet to be addressed.…”

“…Due to the widespread use and advantages associated with the collection of VOCs using sorbent tubes, sample introduction onto chromatographic instrumentation is well established using thermal desorption (TD) . Early studies used conventional GC–MS , while recent investigations have moved towards the use of comprehensive two‐dimensional gas chromatography with time of flight mass spectrometry (GC×GC–TOFMS) .…”

Development of gas chromatography-flame ionization detection system with a single column and liquid nitrogen-free for measuring atmospheric C2–C12 hydrocarbons

“…In addition, the extremely expensive PTR-MS technique also limits its widely application for atmospheric NMHCs measurements. Gas chromatography equipped with flame ionization detection (GC-FID) or mass detection (GC-MS) has been widely used for measuring atmospheric NMHCs, and the isomeric compounds of NMHCs can also be quantified with the help of an efficient separation column [12][13][14][15]. To meet the detection limits of GC-FID/MS, the air samples are needed to be pre-enriched before analyzing [13,16].…”