Raman Handheld Versus Microscopic Spectroscopy for Estimating the Post-Mortem Interval of Human Bones: A Comparative...

Area of Science:

• Forensic science
• Biophysics
• Materials science

Background:

• Accurate post-mortem interval (PMI) estimation is crucial in forensic investigations.
• Conventional methods for PMI estimation can be time-consuming and require specialized expertise.
• Raman spectroscopy offers a potential non-destructive analytical technique for bone analysis.

Purpose of the Study:

• To evaluate the efficacy of Raman spectroscopy for post-mortem interval estimation in human skeletal remains.
• To compare the performance of a handheld Raman device versus a Raman microscope for PMI determination.
• To assess the feasibility of using Raman spectroscopy in non-specialized forensic laboratories.

Main Methods:

• Analysis of 99 autopsy bone samples and 5 archeological bone samples.
• Categorization of samples into five PMI classes using conventional forensic methods.
• Measurement and analysis of key Raman spectral parameters, including ν1PO43- intensity and crystallinity.
• Application of principal component analysis (PCA) for classification of PMI classes.

Main Results:

• Principal component analysis demonstrated high classification accuracy for both handheld and microscopic Raman spectroscopy devices in distinguishing PMI classes.
• Raman spectroscopy effectively identified key spectral markers related to bone degradation over time.
• Fluorescence interference was identified as a challenge, particularly impacting the age determination of archeological samples.

Conclusions:

• Raman spectroscopy, utilizing both handheld and microscopic devices, is a reliable method for enhancing the accuracy of post-mortem interval estimation.
• The technique shows significant potential for application in non-specialized forensic settings, democratizing advanced analytical capabilities.
• Further optimization of Raman devices is recommended to overcome challenges like fluorescence interference and improve applicability to diverse sample types, including archeological remains.