Postmortem metabolomics: Correlating time-dependent concentration changes of xenobiotic and endogenous compounds

Area of Science:

• Forensic Toxicology
• Analytical Chemistry
• Postmortem Biochemistry

Background:

• Postmortem redistribution (PMR) causes artificial xenobiotic concentration changes, complicating forensic toxicology.
• Estimating PMR occurrence after death is currently not possible.
• Postmortem biochemical shifts in blood may correlate with drug redistribution.

Purpose of the Study:

• To investigate correlations between time-dependent xenobiotic and endogenous compound concentration changes postmortem.
• To explore the potential of endogenous compounds as surrogates for studying PMR.
• To lay groundwork for a statistical model to estimate PMR occurrence.

Main Methods:

• Analysis of morphine and methadone concentrations in peripheral blood from 19 and 11 cases, respectively.
• Utilized postmortem metabolomics with targeted (56 analytes) and untargeted (1174 features) approaches.
• Employed liquid and gas chromatography-mass spectrometry for compound analysis.

Main Results:

• Statistically significant correlations were identified between morphine/methadone and specific endogenous compounds/features.
• The study successfully confirmed the general applicability of using endogenous compounds to study PMR.
• Individual correlations provide a basis for further investigation into PMR mechanisms.

Conclusions:

• The concept of correlating endogenous compounds with xenobiotic PMR is validated.
• Future research requires larger datasets to establish robust markers for PMR.
• Developing a statistical model for a posteriori PMR estimation is a critical next step for forensic practice.