Estimation of the post-mortem interval in human bones by infrared spectroscopy

In forensic anthropology, there is an inherent difficulty in estimating the post-mortem interval (PMI). This study aimed to assess whether there is a correlation between changes in the bone mineral component and the PMI estimation. Samples of femur and humerus from 80 identified individuals with known post-mortem interval were analyzed. Infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) was applied for this analysis, several indices having been obtained from the infrared bands most representative of the bone's relative contents in carbonate and phosphate. Specific relationships between sex/age and PMI were attained: for larger PMIs, there was an increase in the amount of B-type carbonate (BPI), A-type carbonates (API), and in the carbonate/phosphate (C/P) ratio, and a decrease of the crystallinity index (CI) and in the carbonate ratio (C/C). Two particular infrared indices (CI and C/C) were identified as the most suitable for post-mortem interval estimation, especially in females, controlling the effects of sex and age (in the statistical analysis).

Automated summary

The study found that changes in bone mineral components can aid in estimating the post-mortem interval, with specific infrared indices identified as the most suitable for estimation, especially in females, controlling for the effects of sex and age in the statistical analysis.