DIRECT ANALYSIS OF RADIOISOTOPES IN COMPLEX SAMPLES BY ACCELERATOR MASS SPECTROMETRY

摘要

Accelerator Mass Spectrometry (AMS) is an ultra sensitive technique for measuring extremely low concentrations of long-lived radioisotopes, such as 14C or 3H. Although it is widely used in radiocarbon dating, two main issues have restricted its application to biomedical research: the size and cost of instruments and the sample preparation procedures. The AMS system at BEAMS Lab has been designed to address these two major restrictions. The design includes two novel interfaces in which liquid non-volatile samples are analyzed directly without the intermediacy of any sample preparation. In these interfaces, samples are converted to CO2 or H2 gas that feeds the accelerator ion source. We describe here the state-of-the-art of both our interfaces and briefly, the results of a pharmacokinetics study on rats that were administered [14C]-acetaminophen. This study lead us to satisfactorily prove the indirect coupling of the system to an HPLC chromatograph. We also show a preliminary report of the measurement of tritiated acetaminophen. Results presented here confirm the potential utility of on-line sample conversion as an alternative to solid sample production for AMS analysis of 14C and 3H.