An Interface for the Direct Coupling of Small Liquid Samples to AMS

Area of Science:

• Analytical Chemistry
• Biochemistry
• Nuclear Science

Background:

• Accelerator Mass Spectrometry (AMS) is a powerful technique for isotope ratio measurements.
• Analysis of nonvolatile liquid samples, especially in biomedical research, presents unique challenges for AMS.

Purpose of the Study:

• To introduce and characterize a novel moving wire interface for AMS analysis of nonvolatile liquid samples.
• To enable the analysis of discrete liquid drops and direct output from chromatographic separations.
• To expand the capabilities of AMS for biomedical applications requiring the measurement of trace biochemicals.

Main Methods:

• Development and implementation of a moving wire interface coupled to a 1-MV AMS system.
• Analysis of discrete liquid samples and samples from high-performance liquid chromatography (HPLC).
• Quantification of carbon (C) and radiocarbon (¹⁴C) content with focus on precision and dynamic range.

Main Results:

• The system can measure discrete samples with as little as 50 zeptomoles (zmol) of ¹⁴C.
• Achieved precision of 3-5% for ¹⁴C measurements in minutes.
• Demonstrated a dynamic range of approximately three orders of magnitude.
• Minimized sample-to-sample memory effects through optimized procedures.

Conclusions:

• The moving wire interface is a viable technology for the AMS analysis of nonvolatile liquid samples.
• This advancement significantly enhances the capacity for low-level biochemical analysis in extremely small samples.
• The technology is expected to broaden the scope of biomedical AMS research, particularly for trace analyte detection.