New protocol for compound-specific radiocarbon analysis of archaeological bones

Area of Science:

• Archaeometry
• Analytical Chemistry

Background:

• Accurate radiocarbon dating requires samples free from contaminating carbon.
• Conventional methods struggle with heavily contaminated bones.
• High-performance liquid chromatography (HPLC) offers an alternative pre-treatment approach.

Purpose of the Study:

• To report significant improvements to an existing HPLC method for bone collagen pre-treatment.
• To enhance the routine application of accelerator mass spectrometry (AMS) dating for contaminated bone samples.

Main Methods:

• Utilized semi-preparative chromatography with non-carbon-based eluents to separate underivatised amino acids from hydrolyzed bone collagen.
• Focused on isolating hydroxyproline, a key carbon contributor in mammalian collagen, for single-compound AMS dating.
• Implemented modifications to hardware and methodology for faster sample preparation.

Main Results:

• Achieved significantly faster semi-preparative separation of hydroxyproline from bone collagen.
• The improved method is more suitable for routine radiocarbon dating of contaminated and poorly preserved bone samples by AMS.
• Detailed description of the entire procedure from collagen extraction to AMS data correction is provided.

Conclusions:

• Modifications to the HPLC method and hardware have substantially reduced sample preparation time.
• The optimized approach is readily implementable by other radiocarbon facilities for routine preparation of contaminated bone samples.