A minimally-invasive method for profiling volatile organic compounds within postmortem internal gas reservoirs

Area of Science:

• Forensic Science
• Analytical Chemistry
• Toxicology

Background:

• Non-invasive postmortem examination methods are crucial in forensic casework.
• Whole body postmortem computed tomography (PMCT) visualizes internal characteristics and gas reservoirs.
• Volatile organic compounds (VOCs) in gas reservoirs may indicate postmortem interval.

Purpose of the Study:

• To develop and optimize solid-phase microextraction (SPME) and GC×GC-HRTOF-MS procedures for analyzing VOCs from postmortem gas reservoirs.
• To assess sample stability and identify optimal analytical parameters.
• To identify potential VOC markers for postmortem interval determination.

Main Methods:

• Optimization of SPME fiber extraction parameters.
• Implementation of a mixed deuterated internal standard approach.
• Analysis of gas reservoirs using comprehensive two-dimensional gas chromatography-high-resolution time-of-flight mass spectrometry (GC×GC-HRTOF-MS).

Main Results:

• Optimized SPME parameters improved VOC profile selectivity and sensitivity.
• Internal standards enhanced data quality.
• Samples remained stable up to 6 weeks, with analysis recommended within 4 weeks.
• 29 VOC markers were identified, with heart/abdominal cavities suggested for standardized sampling.

Conclusions:

• Refined SPME and GC×GC-HRTOF-MS methods provide enhanced VOC analysis for postmortem samples.
• Established sample stability and identified key VOC markers.
• Findings support the development of a routine, accredited method for minimally-invasive VOC analysis in forensic investigations.