Surface characterization of medieval silver coins minted by the early Piasts: FT‐IR mapping and SEM/EDX studies

Abstract

An investigation of a numismatic collection of silver denarii from the early Piast dynasty was conducted using Fourier-transform infrared spectroscopy. The studied coins, minted between 995 and 1020 AD under the rules of Boleslaus the Brave and Mieszko II Lambert, belong to the collection of the National Museum in Kraków. Fourier-transform infrared spectroscopy imaging and mapping have been used for recording a visual image of the surface chemistry based on vibrational spectra and accurately representing the distribution of chemical compounds, respectively. Additionally, scanning electron microscopy coupled to energy-dispersive X-ray analysis was used to study the surface topography of the coins and characterize their elemental composition. Differences in the distribution of the identified chemical compounds were detected in heterogeneous areas of the denarii. Corrosion effects, associated to many factors including the alloy composition, the metallographic structure, the manufacturing processes, and the environment were also observed and identified. KEYWORDSBoleslaus the Brave, Fourier-transform infrared spectroscopy, FT-IR, numismatic studies, scanning electron microscopy coupled to energy-dispersive X-ray analysis, SEM/EDX, silver coins 1 | INTRODUCTION Nowadays, due to the need for high sensitivity, reliability and nondestructiveness, several analytical methods are continuously been developed to study cultural heritage objects, including numismatic collections. Vibrational spectroscopy methods (infrared absorption spectroscopy and Raman spectroscopy), X-ray fluorescence (XRF), and ion beam analysis techniques (particle-induced X-ray emission [PIXE], particle-induced γ-ray emission, and Rutherford backscattering spectrometry) are the most commonly used in this area and allow for high sensitivity and reliable identification. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] These kinds of studies are useful to enrich the discussion on many historical aspects, such as coinage production, provenance of raw materials, forgeries, and conservation treatments. [16][17][18][19][20] In the previously published paper, we have already described the voltammetry of immobilized particles study of a series of 20 denarii from Boleslaus the Brave and Mieszko II Lambert. 21 The analytical results can offer complementary information to archaeologists, art historians, and conservation professionals, interested in finding a correlation between the chemical composition of the coins and their historical, economical, and political aspects.Additionally, numismatic objects have a higher survival rate in comparison to other types of historic artifacts. Therefore, in the last few years there has been an increasing interest in the field of physicochemical analysis of historic coins. However, the analysis can be difficult because of chemical changes and corrosion processes caused by different human and natural factors, which noticeably alter the surface composition of the objects. 22,23 In a previous paper, 16 XRF analysis was performed...

Vibrational Fingerprint of Erlotinib: FTIR, RS, and DFT Studies

“…However, there are some differences for the C-O-C and O-C-C bond angles of erlotinib in comparison with those from the mentioned aromatic isomer [35]. e C 13 -O 20 -C 21 , C 14 In the case of the corresponding bonds [35,36], these angles are equal to 116.6°and 107.7°, respectively. Figure 2 presents experimental and theoretical RS and FTIR spectra for the erlotinib drug in the spectral range of 2250-400 cm − 1 .…”

“…Bond length (Å) Bonds Angle (°) Bonds Dihedral angle (°) C 1 -C 2 1.204 C 2 -C 3 -C 8 119.5 C 6 -C 7 -N 9 -C 10 − 179.3 C 2 -C 3 1.430 C 8 -C 7 -N 9 124.5 N 9 -C 10 -C 11 -C 12 1.071 C 3 -C 4 1.403 N 9 -C 10 -N 19 120.0 C 11 -C 12 -C 13 -O 20 174.9 C 4 -C 5 1.390 N 9 -C 10 -C 11 118.8 C 16 -C 15 -C 14 -O 25 − 179.1 C 5 -C 6 1.388 C 10 -C 11 12 1.414 C 15 -C 14 -O 25 125.0 C 12 -C 13 1.374 C 14 -O 25 -C 26 118.9 C 13 -C 14 1.433 O 25 -C 26 -C 27 108.4 C 14 -C 15 1.378 C 26 -C 27 -O 28 109.4 C 15 -C 16 1.414 C 27 -O 28 -C 29 112.8 C 16 -N 17 1.367 N 17 -C 18 1.310 C 18 -N 19 1.351 N 19 -C 10 1.323 C 11 -C 16 1.418 C 13 -O 20 1.364 O 20 -C 21 1.441 C 21 -C 22 1.519 C 22 -O 23 1.418 O 23 -C 24 1.412 C 14 -O 25 1.356 O 25 -C 26 1.428 C 26 -C 27 1.511 C 27 -O 28 1.412 O 28 -C 29 1.414…”

“…ese studies present vibrational spectroscopy characterization by means of Raman spectroscopy (RS) and Fourier-transform infrared absorption spectroscopy (FTIR) of the molecular structure of erlotinib in the solid state and solution in different pH conditions. ese two complementary methods are commonly used for qualitative and quantitative analysis of different types of samples in various conditions and physical states [10][11][12][13][14][15]. RS and FTIR are governed by different quantum mechanical selection rules [16].…”

Novel use of XRF in the adsorption processes for the direct analysis of cadmium and silver in absorbent Na-alginate beads

“…Overall, although undirected, approximate estimated and complicated method (peak detectionbased (SEM-EDX) has been used in the inaccurate estimation of elements generally and of Cd (23) and Ag (24) especially. The present study reported the first use of XRF in the direct analysis of an example of elements, Cd and Ag, which were absorbed within the Na-alginate beads in batch adsorption experiments.…”

Surface and elemental analysis of 20th century Romanian coins using SEM-EDX technique

“…Such techniques that respect these strict conditions are: energy dispersive X-ray fluorescence (ED-XRF) [1][2][3][4], scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) [3][4][5], vibrational spectroscopy methods [5,6], optical microscopy [7], particle induced X-ray emission (PIXE) [3,4,7].…”