The goal of this research project was to expand the ability of forensic anthropologists and pathologists to approximate the time since death from the analysis of skeletal remains using quantitative lipidomics.
The study involved identifying lipid candidates in bone marrow that survived initial soft tissue decomposition processes and were retained for long-term postmortem intervals (PMI). This study is distinctive in its attempt to use quantitative methods to trace the molecular degradation of lipid compounds using high resolution mass spectrometry. The broad goal of this project was to expand lipid data on postmortem intervals of less than 1 year to approximately 30 years since death. Bone biopsy samples of fresh and skeletal donors with varying postmortem intervals (approximately 1-30 years) were subjected to high resolution mass spectrometry to identify preserved lipid biomolecules in bone. The degradation of the identified compounds was tracked for 24 months using relative quantitation methods. Bone biopsies were performed at the sites of medial caicaneus, proximal tibia, and vertebral body (fourth lumbar). The experimental sample and the cross-sectional sample are described, and the findings from the experimental and cross-sectional studies are reported. They indicate that the PMI between 0 and 3 months is the critical period for degradation of bone phosphatidyicholines and that these compounds are preserved in bone at low levels for decades. Although this study established the linear degradation of several phosphatidylcholines housed in trabecular bone, the next step will be to investigate the 0-3-month time interval in more detail. It is also suggested that this analytical approach establish and use an absolute rather than relative quantitation method. This facilitates the establishment of a database between various laboratories. 4 tables and 4 references