Differentiation between decomposed remains of human origin and bigger mammals

This study is a follow-up study in the search for a human specific marker in the decomposition where the VOC-profile of decomposing human, pig, lamb and roe remains were analyzed using a thermal desorber combined with a gas chromatograph coupled to a mass spectrometer in a laboratory environment during 6 months. The combination of 8 previously identified human and pig specific compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, 3-methylthio-1-propanol, methyl(methylthio)ethyl disulfide, diethyl disulfide and pyridine) was also seen in these analyzed mammals. However, combined with 5 additional compounds (hexane, heptane, octane, N-(3-methylbutyl)- and N-(2-methylpropyl)acetamide) human remains could be separated from pig, lamb and roe remains. Based on a higher number of remains analyzed, as compared with the pilot study, it was no longer possible to rely on the 5 previously proposed esters to separate pig from human remains. From this follow-up study reported, it was found that pyridine is an interesting compound specific to human remains. Such a human specific marker can help in the training of cadaver dogs or in the development of devices to search for human remains. However, further investigations have to verify these results.</p

Comparison of liquid chromatography and capillary electrophoresis methods for quantification of sodium residuals

Liquid chromatography (LC) and capillary electrophoresis (CE) methods were developed to perform the determination of residual sodium in mother liquors and successive washes of an active pharmaceutical ingredient (API). The addition of sodium chloride to the product solution results in rapid and complete crystallization of the API. The LC method was coupled to evaporative light scattering detection (ELSD) while the CE approach was based on indirect UV detection. Both methods were fully validated. Selectivity, response function, trueness, precision, accuracy, linearity and limits of detection (LOD) and quantification (LOQ) were the criteria investigated. The LC-ELSD method was found to be more sensitive than the CE/indirect UV approach. The methods were found to be valid over concentration ranges of 62-500 and 235-1500 ppm for the LC and the CE methods, respectively. Both methods were compared and used for the determination of actual samples coming from different batches of the same API chemical synthesis. (c) 2006 Elsevier B.V. All rights reserved

Time-dependent VOC-profile of decomposed human and animal remains in laboratory environment

A validated method using a thermal desorber combined with a gas chromatograph coupled to a mass spectrometer was used to identify the volatile organic compounds released in decomposed human and animal remains after 9 and 12 months in glass jars in a laboratory environment. This is a follow-up study on a previous report where the first 6 months of decomposition of 6 human and 26 animal remains was investigated. In the first report, out of 452 identified compounds, a combination of 8 compounds was proposed as human and pig specific. The goal of the current study was to investigate if these 8 compounds were still released after 9 and 12 months. The next results were noticed: 287 compounds were identified; only 9 new compounds were detected and 173 were no longer seen. Sulfur-containing compounds were less prevalent as compared to the first month of decomposition. The appearance of nitrogen-containing compounds and alcohols was increasingly evident during the first 6 months, and the same trend was seen in the following 6 months. Esters became less important after 6 months. From the proposed human and pig specific compounds, diethyl disulfide was only detected during the first months of decomposition. Interestingly, the 4 proposed human and pig specific esters, as well as pyridine, 3-methylthio-1-propanol and methyl(methylthio)ethyl disulfide were still present after 9 and 12 months of decomposition. This means that these 7 human and pig specific markers can be used in the development of training aids for cadaver dogs during the whole decomposition process. Diethyl disulfide can be used in training aids for the first month of decomposition. </p

The Search for a Volatile Human Specific Marker in the Decomposition Process

In this study, a validated method using a thermal desorber combined with a gas chromatograph coupled to mass spectrometry was used to identify the volatile organic compounds released during decomposition of 6 human and 26 animal remains in a laboratory environment during a period of 6 months. 452 compounds were identified. Among them a human specific marker was sought using principle component analysis. We found a combination of 8 compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, pyridine, diethyl disulfide, methyl(methylthio)ethyl disulfide and 3-methylthio-1-propanol) that led to the distinction of human and pig remains from other animal remains. Furthermore, it was possible to separate the pig remains from human remains based on 5 esters (3-methylbutyl pentanoate, 3-methylbutyl 3-methylbutyrate, 3-methylbutyl 2-methylbutyrate, butyl pentanoate and propyl hexanoate). Further research in the field with full bodies has to corroborate these results and search for one or more human specific markers. These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed.status: publishe

Suggested human specific compounds found in literature and if they were detected in our study (X) [2, 3, 19].

<p>Suggested human specific compounds found in literature and if they were detected in our study (X) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137341#pone.0137341.ref002" target="_blank">2</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137341#pone.0137341.ref003" target="_blank">3</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137341#pone.0137341.ref019" target="_blank">19</a>].</p

Overview of species used in previous decomposition studies.

<p>Overview of species used in previous decomposition studies.</p