Perrault Katelynn A, Stefanuto Pierre-Hugues, Dubois Lena M, Varlet Vincent, Grabherr Silke, Focant Jean-François
Forensic Sciences Unit, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI, 96815, USA.
Organic and Biological Analytical Chemistry Group, University of Liège, Allée du 6 Août, 11, B6c, Quartier Agora (Sart-Tilman), 4000, Liège, Belgium.
Int J Legal Med. 2017 Sep;131(5):1271-1281. doi: 10.1007/s00414-017-1621-7. Epub 2017 Jun 15.
In forensic casework, non-invasive and minimally-invasive methods for postmortem examinations are extremely valuable. Whole body postmortem computed tomography (PMCT) is often used to provide visualization of the internal characteristics of a body prior to more invasive procedures and has also been used to locate gas reservoirs inside the body to assist in determining cause of death. Preliminary studies have demonstrated that exploiting the volatile organic compounds (VOCs) located in these gas reservoirs by comprehensive two-dimensional gas chromatography-high-resolution time-of-flight mass spectrometry (GC×GC-HRTOF-MS) may assist in providing information regarding the postmortem interval. The aim of the current study was to further develop the procedures related to solid-phase microextraction (SPME) and GC×GC-HRTOF-MS analysis of gas reservoirs collected from deceased individuals. SPME fiber extraction parameters, internal standard approach, and sample stability were investigated. Altering the SPME parameters increased the selectivity and sensitivity for the VOC profile, and the use of a mixed deuterated internal standard contributed to data quality. Samples were found to be stable up to 6 weeks but were recommended to be analyzed within 4 weeks due to higher variation observed beyond this point. In addition, 29 VOC markers of interest were identified, and heart and/or abdominal cavity samples were suggested as a possible standardized sampling location for future studies. The data presented in this study will contribute to the long-term goal of producing a routine, accredited method for minimally-invasive VOC analysis in postmortem examinations.
在法医案件工作中，非侵入性和微创性的尸体检验方法极具价值。全身尸体计算机断层扫描（PMCT）常用于在进行更具侵入性的程序之前提供尸体内部特征的可视化，并且也被用于定位体内的气体储存库以协助确定死因。初步研究表明，通过全二维气相色谱 - 高分辨率飞行时间质谱（GC×GC - HRTOF - MS）利用这些气体储存库中的挥发性有机化合物（VOCs）可能有助于提供有关死后间隔的信息。本研究的目的是进一步开发与从死者身上收集的气体储存库的固相微萃取（SPME）和GC×GC - HRTOF - MS分析相关的程序。研究了SPME纤维萃取参数、内标方法和样品稳定性。改变SPME参数提高了VOC谱图的选择性和灵敏度，使用混合氘代内标有助于提高数据质量。发现样品在长达6周内是稳定的，但由于在此之后观察到更高的变异性，建议在4周内进行分析。此外，确定了29种感兴趣的VOC标志物，并建议将心脏和/或腹腔样本作为未来研究可能的标准化采样位置。本研究中呈现的数据将有助于实现长期目标，即开发一种用于尸体检验中微创VOC分析的常规、认可方法。
