Profiling of human burned bones: oxidising versus reducing conditions

Area of Science:

• Biomolecular Spectroscopy
• Forensic Anthropology
• Materials Science

Background:

• Human skeletal remains are crucial in forensic and archaeological investigations.
• Understanding thermal alteration effects on bone composition is vital for accurate interpretation.
• Previous studies have not fully explored anaerobic heating effects on bone using inelastic neutron scattering.

Purpose of the Study:

• To investigate the effects of aerobic versus anaerobic thermal conditions on human bone composition.
• To characterize thermally altered bone using complementary vibrational spectroscopy techniques.
• To establish a spectroscopic basis for differentiating bone samples based on oxygen availability during heating.

Main Methods:

• Human femur and humerus samples were subjected to controlled aerobic and anaerobic burning at temperatures ranging from 400 to 1000 °C.
• Infrared (IR) spectroscopy, Raman spectroscopy, and inelastic neutron scattering (INS) were employed for analysis.
• Comparative analysis focused on vibrational bands associated with bone mineral and organic components.

Main Results:

• Distinct spectroscopic signatures were observed between aerobically and anaerobically heated bone samples.
• Anaerobically heated bone showed the absence of hydroxyapatite's OH vibrational bands.
• Cyanamide (NCNH2) and portlandite (Ca(OH)2) were identified in anaerobically heated bone, indicating specific chemical transformations under reductive conditions.

Conclusions:

• The study successfully differentiated bone samples based on oxygen availability during thermal alteration using vibrational spectroscopy.
• The findings provide a foundation for improved characterization of burned human skeletal remains in diverse forensic and archaeological scenarios.
• This research highlights the significance of environmental conditions, particularly oxygen availability, in post-mortem thermal degradation of bone.