Use of a hybrid sputtering ion source for the determination of the bio-derived carbon fraction in particulate matter

The development of analytical methods capable of discriminating between bio-derived and fossil-derived carbon in Particulate Matter (PM) is a crucial aspect in the general efforts of identifying effective strategies for health-risks mitigations. The large difference in the isotopic signature between bio-derived and fossil derived materials in term of the concentration of 14C the radioactive carbon isotope can be effectively used for this purpose. Indeed, though the detection and measurement of 14C by AMS (Accelerator Mass Spectrometry) is a well established methodology, the reduced amount of carbon in PM samples (typically in the μg range) requires the use of proper ion sources with a high efficiency. We present here the set-up developed at CEDAD-University of Salento as based on a gas-accepting hybrid ion source and an in-house designed gas handling interface. The performances of the system are also shown by presenting the firsts tests carried out on PM sampled on quartz filters in Lecce, Italy.