Accelerator Mass Spectrometry: An Analytical Tool with Applications for a Sustainable Society

Accelerator Mass Spectrometry (AMS) adds the techniques of charged particle acceleration to the basic principles of Isotope Ratio Mass Spectrometry (IRMS) to provide extremely low detection capability (below 1 femtogram) of rare isotopes in in samples of natural materials as small as 1 mg. Depending on the element selected and the configuration of the equipment, sensitivities can reach one part in 1015. The advantages of this small sample size and high sensitivity include the economic benefit of collecting, shipping and preparing much smaller samples, and also the ability to analyse specific chemical compounds within the sample, so that the pathway taken by that compound through complex systems can be more precisely traced or, in the case of radioactive isotopes, more precise chronological information can be provided. There are currently approximately 160 AMS systems in operation throughout the world, ranging in acceleration voltage from 200 kV to 15 MV, a number which has doubled in the past 10 years. While many which operate at the lowest of these voltages are specifically designed for one element (typically carbon isotopes), there are a number of multi-element machines coming online which operate at 300 kV. Many of these systems can be equipped with integrated sample preparation equipment, such as elemental analyzers, carbonate analysis systems or even IRMS systems for abundant stable isotope analyses of the same sample.