Measurement of β-nuclides in various solutions using plastic scintillation microspheres

Area of Science:

• Radiochemistry
• Materials Science

Background:

• Conventional scintillation cocktails are unsuitable for samples with extreme acidity or alkalinity in beta-nuclide liquid scintillation analysis.
• Plastic scintillation microspheres (PSm) present a novel material for direct sample measurement, overcoming limitations in challenging chemical environments.

Purpose of the Study:

• To evaluate the performance and stability of plastic scintillation microspheres (PSm) in diverse and extreme chemical conditions.
• To assess the suitability of PSm for beta-nuclide analysis in complex matrices.

Main Methods:

• PSm were tested in various acidic (nitric, hydrochloric, sulfuric, phosphoric), alkaline (NaOH), high-salinity, and methanol solutions.
• Chemical stability, chemiluminescence, and potential quenching effects were observed.
• Efficiency calibration was performed using ultrapure water for 14C activity measurements.

Main Results:

• PSm formed stable mixtures with most tested solutions, showing excellent stability in high-concentration NaOH with minimal chemiluminescence.
• Concentrated nitric and sulfuric acids induced chemical reactions, causing discoloration and potential quenching.
• Accurate 14C activity measurements were achieved across solutions with simple efficiency corrections.

Conclusions:

• Plastic scintillation microspheres (PSm) are advantageous for beta-nuclide measurement in complex chemical environments, including highly acidic, alkaline, and saline conditions.
• PSm offer a reliable and efficient alternative to traditional scintillation cocktails for applications like radioactive waste monitoring and pharmacokinetic research.