The potential of accelerator-based techniques as an analytical tool for forensics: The case of coffee.

We discuss how different accelerator-based techniques can be employed synergistically as a powerful analytical tool for forensic studies of foodstuff. Brazilian and Jamaican coffees were chosen as a showcase due to its popularity and potential risk of adulteration and/or falsification. Comprehensive characterization of major and trace elements, age since production and compound contents were achieved using different techniques, including PIXE (Particle-Induced X-ray Emission), FTIR (Fourier Transform Infrared), and AMS-14C (Accelerator Mass Spectrometry - Radiocarbon Analysis). While PIXE provides information on the elements present in the samples, FTIR probes the types of compounds through their vibrational spectra. Finally, AMS-14C is capable of dating organic samples regarding their harvesting time. Five different laboratories from research institutions around the world took part in the experiments. The integration of the results obtained with different techniques provided multifaceted perspectives on the coffee under study, thus allowing a direct assessment of the material for forensic purposes such as authentication, determination of provenance, and combat counterfeiting.

Coster-kronig decay of the ar2s hole observed by auger-threshold photoelectron coincidence spectroscopy

The Coster-Kronig lines associated with Ar2s decay have been resolved within the natural linewidth of the 2s hole for the first time. This was possible by a new spectroscopic technique, relying on resonance enhanced double photoionization, Auger-threshold photoelectron coincidence spectroscopy. Contrary to standard Auger spectroscopy, this technique can filter out weak components in Auger spectra corresponding to a well-defined inner-shell state and, furthermore, can achieve a resolution no longer limited by the lifetime of the inner-shell hole.