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Marguà Grabulosa, Eva
Queralt i Mitjans, Ignasi |
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Universitat de Girona. Facultat de Ciències | |
Castillo Muriel, Marina | |
2023 July | |
The objective of this final degree project is to develop a new methodology for the analysis of the
elemental composition of noble metal alloys, according to the recently approved ISO DIS 23345
regulation. This new methodology is intended to be put into practice in common forensic
analyses to intervene in expert trials of crimes of counterfeiting or theft of jewellery or gold
objects. The motivation to develop this new method has been the multiple advantages that it allegedly
presented over cupellation, the current official method of gold analysis according to the laws
established by Spanish legislation. The official method presents significant drawbacks: high
analysis time, destruction of the sample, generation of waste, high energy cost and
consumption of reagents, among others. Since the X-ray spectroscopy technique could overcome these drawbacks, it was proposed to develop the new methodology. The analysis is carried out thanks to the energy dispersive X-ray microfluorescence technique (ED-XRF). Likewise, first of all, a general calibration was developed, which included the elements commonly found in jewellery. For this, appropriate reference materials were used, a total of 33 standards of different composition. Subsequently, a specific calibration for the Au-Ag-Cu alloy was carried out and all
of this was subjected to a study to confirm that the methodology complied with the ISO DIS
23345 regulation. The results of these calibrations were satisfactory, so the study continued
Forward. Thus, the next step was the quantitative analysis of different privately owned jewels to
determine if they were legal gold, plated or counterfeit, also being able to determine their
composition precisely, fulfilling the proposed objective.
It was possible to determine that, of the seven jewels analysed, only four were legal gold, so the
remaining three did not present the minimum amount of gold required by the BOE, 18K 9 |
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application/pdf | |
http://hdl.handle.net/10256/24347 | |
cat | |
Attribution-NonCommercial-NoDerivatives 4.0 International | |
http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
Espectroscòpia de fluorescència
Espectroscòpia de raigs X Metalls preciosos -- Anà lisi Laboratoris d’analÃtica forense QuÃmica legal Photoelectron spectroscopy X-ray spectroscopy Precious metals -- Analysis Crime laboratories Chemistry, Forensic ISO DIS 23345 |
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La Micro-fluorescència de raigs X en estudis forènsics : anà lisi d’aliatges de metalls nobles d’acord amb la norma ISO/DIS 23345/(2020) | |
info:eu-repo/semantics/bachelorThesis | |
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