Experimental estimation of postmortem interval using multivariate analysis of proton NMR metabolomic data

Area of Science:

• Biochemistry
• Forensic Science
• Analytical Chemistry

Background:

• Nuclear magnetic resonance (NMR) spectroscopy is increasingly used for metabolic studies.
• Multivariate analysis of NMR spectra enables metabolic profiling of tissues and whole bodies.

Purpose of the Study:

• To investigate postmortem metabolic alterations in rat femoral muscles.
• To assess the utility of proton NMR spectroscopy and pattern recognition for determining the cause and time of death.

Main Methods:

• Rat femoral muscles were analyzed using proton NMR spectroscopy after death by suffocation, cocaine overdose, or respiratory failure.
• Low molecular weight metabolites were extracted and measured.
• Multivariate analysis, including principal component analysis (PCA), was applied to spectral data.

Main Results:

• Metabolic profiles differed based on the mode of death, as shown by PCA score plots.
• Principal component (PC) scores varied hourly and correlated with the postmortem interval.
• NMR-based metabolic profiling provided distinct signatures related to death circumstances.

Conclusions:

• Proton NMR spectroscopy combined with multivariate analysis is effective for metabolic profiling of postmortem tissues.
• This approach holds potential for estimating postmortem intervals and determining causes of death in forensic investigations.