Comparison of decomposition techniques for solid samples with emphasis on actinide content determination.

Area of Science:

• Analytical Chemistry
• Radiochemistry

Background:

• Accurate determination of actinide content in solid samples is crucial for environmental monitoring and nuclear waste management.
• Conventional acid digestion methods can leave undissolved residues, complicating subsequent radiochemical separation and analysis.

Purpose of the Study:

• To compare the effectiveness of conventional acid digestion and thermal fusion for dissolving solid samples for actinide analysis.
• To evaluate the impact of sample amount and tracer addition timing on dissolution efficiency.
• To optimize sample preparation for radiochemical separation and subsequent actinide determination.

Main Methods:

• Solid samples were subjected to two dissolution methods: conventional acid digestion (using HNO3, HClO4, HF) and thermal fusion (using Li borate).
• Parameters investigated included sample mass and tracer addition timing (pre- and post-dissolution).
• Actinide content was determined using alpha-particle spectrometry and neutron activation analysis.

Main Results:

• Thermal fusion achieved complete dissolution without any residue, unlike acid digestion.
• The absence of residue in the fusion method eliminated the need for filtration before radiochemical separation.
• Both alpha-particle spectrometry and neutron activation analysis were successfully applied to determine actinides in original samples and dissolution residues.

Conclusions:

• Thermal fusion is a more effective sample dissolution technique than conventional acid digestion for solid samples requiring actinide analysis.
• Eliminating the filtration step simplifies the radiochemical separation process, improving accuracy and efficiency.
• The optimized fusion method facilitates reliable determination of actinides in complex solid matrices.