Multielement analysis in beer cans using X-ray fluorescence

In this study the elemental concentrations of twenty-three beer cans of different brands and nationalities were determined using X-ray fluorescence technique. Beer cans from Brazil (20 beer cans), Germany, the United Kingdom and Colombia were analyzed, totalizing 15 different breweries. It was possible to calculate the concentration of 15 elements in the beer cans samples: Mg, Al, Si, S, Cl, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Zr and Pb. The results showed that aluminum concentrations ranged from 94 % to 96 %. Other's elements can be considered trace elements, being the highest concentrations of them for Mg (approximately 2%) and Mn (approximately 1%). Some elements showed differences between cans from different nationalities, with Zn being much higher in samples from Brazil. The Zr element showed similarities between German and UK beer cans. In addition, the beer can sample from Colombian had lower concentrations of Cl and Ga. This study shows that the values found are comparable to those found in the literature and that the concentrations of some trace elements in beer cans may represent signs of impurities brought during the recycling process

Non-invasive characterization of the painting Saint John the Evangelist by means spectroscopic methods

In this work, the pigments and ground layers of the Saint John the Evangelist painting were analyzed using the techniques of computed radiography, X-ray fluorescence (XRF), and micro-Raman spectroscopy. The painting was purchased by a collector at auction as a 19th-century work of art of unknown authorship. XRF analyzes were performed with a voltage of 40 kV, current of 50 µA, and acquisition time of 60 s. Micro-Raman spectroscopy measurements of a black fragment sample were performed with the Thermo Scientific – DXR2 Raman microscope equipment. The sample was excited by the adjusted 785 nm laser source with a power of 4 mW, focused on the sample using a 100x objective. It was possible to characterize the pigments used in the painting of São João Evangelista as Lead White, Vermilion, Carbon Black, and Ocher. No areas of repainting and modern pigments were identified that could suggest any type of intervention