In this work, a study of detection systems in portable X-ray fluorescence (PXRF) spectrometry was performed. An assessment of various detectors and their influence on the measurement of trace elements in different bulk materials, from light to heavy matrices, was done. Four reference materials were analyzed: Orchard Leaves (NBS-1571); Bone Meal (NIST-1486); River Sediment (NBS-1645) and Free-Cutting Brass (NBS-1105). Detection limits were calculated for the elements present in the reference materials, quantitative calculations were performed for three known samples and a comparison was made for each detector. Three case studies were also performed in order to appraise the behavior of the detection systems: A paper document from 1909, a potassium alum/calcite mixture and a Portuguese coin.

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Synchrotron radiation X-ray fluorescence spectroscopy, in conjunction with atomic absorption and Raman spectroscopy, was used to analyze a set of top brand tattoo inks to investigate the presence of toxic elements and hazardous substances. The Cr, Cu, and Pb contents were found to be above the maximum allowed levels established by the Council of Europe through the resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent makeup. Raman analysis has revealed the presence of a set of prohibited substances mentioned in ResAP(2008)1, among which are the pigments Blue 15, Green 7, and Violet 23. Other pigments that were identified in white, black, red, and yellow inks are the Pigment White 6, Carbon Black, Pigment Red 8, and a diazo yellow, respectively. The present results show the importance of regulating tattoo ink composition.

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In this work, the thickness of the gold leaf applied in the Manueline foral charter of Murça (illuminated in 1512) will be determined using X-ray fluorescence. In the frontispiece of the Manueline foral charter of Murça, the capital D was gilded using a gold leaf over a priming made of lead white. The characteristic lines of Pb (namely Lα and Lβ), although attenuated in the Au layer, are still visible in the X-ray fluorescence spectra. By determining the intensity ratio Lα/Lβ and comparing it with the ratio for an infinitely thick sample, the thickness of the attenuating material can be determined. Using this methodology, the thickness of the gold leaf applied in the charter of Murça was estimated as 1.6 μm.