Nondestructive analysis of Portuguese “dinheiros” using XRF: overcoming patina constraints

Determination of gold leaf thickness using X-ray fluorescence spectrometry: Accuracy comparison using analytical methodology and Monte Carlo simulations

“…Quantification of XRF spectra, obtained with a benchtop commercial setup M4Tornado, using Fundamental parameter method for bulk samples (Pessanha et al, 2015), determined 99.9% Cu with traces of Fe and Pb.…”

2016 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and its applications

“…The mysterious presence of mercury enrichment on the surface of silver coins of the Persian Emperor Khusro II (591-628) was examined using m-XRF spectrometry by Uhlir et al 290 Following more detailed measurements using other microanalysis techniques, the authors postulated that the source of mercury might be historic medical treatments. Pessanha and colleagues 291 were also interested in overcoming patina constraints in the XRF analysis of Portuguese dinheiros coins (the rst Portuguese coins to be minted with a billon alloy comprising Cu alloyed with Ag). Silver K/L intensity ratios from these coins (with a corrosion layer of unknown thickness) were measured in order to choose 'clean' spots for quantitative analysis.…”

Detection limits evaluation of a portable energy dispersive X‐ray fluorescence setup using different filter combinations

“…The Bruker M4 Tornado enables four combinations of filters. Pessanha et al used a composite filter to reduce background (100 µm Al/50 µm Ti/25 µm Cu) in the study of Portuguese dinheiros, while Manso et al used only the 100 µm Al to favor the light element determination in a papier machê sculpture. Kocsonya et al used a filter with different layers (25 µm Ag + 25 µm Cu + 100 µm Al) to ‘imitate’ the characteristics of 109 Cd radioisotope source owing to its favorable analytic properties.…”

“…The use of an aluminum filter is very common in EDXRF . It can act as a simple absorption filter owing to the absorption edge at 1.56 keV and also absorbs L lines from the X‐ray tube (normally Ag, Rh or Mo) as a consequence of the high‐mass absorption coefficient for these energies.…”

“…The thickness of the filter is variable along the common setups (from 100 to 300 µm), and this will determine the attenuation of the low‐energy side of the spectrum. Copper is also commonly used as an absorption filter . With an absorption edge at 8.98 keV, this filter will attenuate the bremsstrahlung ‘hump’ of the X‐ray tube, providing high peak‐to‐background ratios for the elements with lines from the 5 up to 8 keV range.…”