Laser-based radiocarbon detection in the laboratory: How soon?

Area of Science:

• Analytical Chemistry
• Biomedical Science
• Radiochemistry

Background:

• Accelerator Mass Spectrometry (AMS) has been the gold standard for single-atom counting of Carbon-14 (¹⁴C) for 25 years.
• AMS offers superior sensitivity over scintillation monitoring for applications like pharmacokinetics, metabolism studies, microdosing, and DNA adduct quantification.
• Traditional methods often require high radioactivity levels and complex infrastructure.

Purpose of the Study:

• To explore laser-based single-atom counting as a viable alternative to AMS and scintillation monitoring.
• To assess the potential for simplified, laboratory-based systems with high sensitivity and convenience.
• To address challenges in routine application, including signal separation, precision, accuracy, measurement time, and ease of use.

Main Methods:

• Utilized optical storage cavities to enhance laser interaction with low densities of radiocarbon.
• Investigated two laser technologies: cavity ring-down spectroscopy (CRDS) and intracavity opto-galvanic spectroscopy (ICOGS).
• Focused on achieving high sensitivity comparable to or exceeding AMS.

Main Results:

• Demonstrated the feasibility of laser-based single-atom counting for ¹⁴C.
• Achieved impressive results with CRDS using samples of approximately 1 mg and ICOGS using samples of 10 μg.
• Showcased potential for systems that equal or excel AMS sensitivity with scintillation system convenience and reduced radioactivity.

Conclusions:

• Laser-based spectroscopy (CRDS and ICOGS) presents a promising avenue for sensitive ¹⁴C quantification in drug development.
• These methods offer a pathway to simplified, safer, and more convenient laboratory-based radiocarbon analysis.
• Commercial development is the logical next step to bring these advanced analytical capabilities to routine use.