CONICET | Buscador de Institutos y Recursos Humanos

The authentication of philatelic pieces is a complicated task that usually requires several processes, including the inspection and evaluation of experts, the observation with optical microscopes, UV assessments and IR examinations; application of Raman spectroscopy, EPMA and DXR techniques have been reported. There are very few references of the application of XRF techniques to philately and, certainly, applications of this technique to philately in Argentina are not known. The utilization of XRF in philately can be very diverse but its basic application consists of qualitative (quantitative if possible) elemental determination of the components of the different inks used, either on stamps, postmarks or postage stamps. One of the most immediate analysis consists of studying the inks of the postmarks. In this work we present qualitative analysis by x ray fluorescence with spatial resolution of postmark inks of several postal pieces, some of them recognized by experts as authentic ones and others as fake ones. The measurements were carried out using a conventional spectrometer with sample-positioning stages; microbeams were attained by micro-collimators and also a mono-capillary. The results obtained in this work indicate that XRF with spatial resolution is a suitable technique for the authentication of postal pieces through the identification of the elements that constitute the used inks.