The Effect of Soft Tissue on Temperature Estimation from Burnt Bone Using Fourier Transform Infrared Spectroscopy

Area of Science:

• Forensic Science
• Biomaterials Analysis
• Spectroscopy

Background:

• Accurate determination of bone burning temperatures is crucial in forensic investigations.
• Fourier Transform Infrared Spectroscopy (FTIR) is a potential tool for analyzing heat-induced changes in bone.
• The influence of soft tissue and exposure duration on FTIR analysis of burnt bone requires further investigation.

Purpose of the Study:

• To investigate the impact of soft tissue and varying exposure times on predicting bone burning temperatures using FTIR.
• To establish the accuracy of FTIR in estimating burn temperatures from bone samples.
• To understand how soft tissue affects bone matrix alterations during combustion at different temperatures.

Main Methods:

• Ovis aries rib bones were subjected to controlled burning at various temperatures and durations.
• Fourier Transform Infrared Spectroscopy (FTIR) was employed to analyze the spectral changes in the bone samples.
• Linear regression analysis was used to correlate spectral data with known burning temperatures.

Main Results:

• Burn temperatures of defleshed bone could be predicted with a standard error of ±70 °C using FTIR.
• Exposure time did not significantly affect the accuracy of temperature prediction.
• Soft tissue presence significantly altered bone matrix combustion: it slowed combustion at low temperatures (<300 °C) and accelerated it at high temperatures (>800 °C).

Conclusions:

• FTIR analysis of bone provides a reliable method for estimating burning temperatures, particularly from defleshed samples.
• The presence of soft tissue is a critical factor influencing bone combustion dynamics, with differential effects at low and high temperatures.
• These findings offer forensic investigators enhanced insights for interpreting crystallinity data from burnt bone, improving post-fire analyses.