The goal of this project is to develop an exceptionally compact, high throughput tritium accelerator mass spectrometer (AMS) to enable ultra-sensitive tracer studies relevant to the molecular analysis of cancer. The proposed tritium AMS will operate at much lower energy than existing multi-isotope AMS instruments, and will incorporate a sample inlet that can be coupled to a wide variety of liquid micro-flow sample preparation systems. AMS is a powerful tool for detection of rare isotopes such as tritium that are commonly used to radiolabel organic biomolecules, with detection limits in the attomole (10exp-18 mole) and lower range. In contrast to existing instrumentation, an AMS designed exclusively for detection of tritium may be as compact and inexpensive as conventional mass spectrometers. As currently practiced, analysis of biological samples by AMS is limited by the requirement for highly specialized sample preparation procedures that are not compatible with on-line and rapid detection applications. The instrument proposed here addresses this shortcoming by integrating a specialized sample interface into the overall design. The goals of Phase I are to develop and optimize the interface, to experimentally determine the feasibility of tritium AMS at very low energy, and to develop a design to be implemented in Phase II.
