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

Pessanha, Sofia; Queralt, I.; Carvalho, Luísa; Sampaio, J. M.

doi:10.1016/j.apradiso.2019.06.014

Cited by 23 publications

(9 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As reported in Brocchieri et al, [ 7 ] the use of excitation directed from the source, without filtering, produces lower intensity ratios which deviate somewhat from the theoretical curve. As expected, the determined thicknesses are less accurate when using unfiltered radiation, as also shown in Pessanha et al [ 26 ]…”

Section: Resultssupporting

confidence: 72%

“…This is not the case in most circumstances, where only some kind of filtering is used to partially reduce the background or even no filtering and the direct bremsstrahlung from the tube is applied for analysis. [ 26 ] When an infinitely thick sheet of metal is covered by a sheet of another metal, the ratio K α /K β or L α /L β is further altered because of the attenuation of the sheet coating. The theoretical fit (Equation ) in Brocchieri et al [ 7 ] ) was performed to verify the experimental data.…”

Section: Resultsmentioning

confidence: 99%

“…These are attenuated by the gilded layer according to the linear attenuation coefficient. [ 7,10,26 ]…”

Section: Theoretical Backgroundmentioning

confidence: 99%

See 2 more Smart Citations

Gold‐coating thickness determination on Ag, Cu, Fe, and Pb using a handheld X‐ray instrument

2021

View full text Add to dashboard Cite

Here, the X‐ray fluorescence technique is used to determine the thickness of a coating layer as well as to analyze the surface of objects. Four metals (Ag, Cu, Fe, Pb) were covered with increasing thicknesses of gold. The measurements were performed with a commercial handheld instrument, X‐SORT (Spectro). In double layers, the thickness of the covering layer was assessed by (a) the ratio between the most intense fluorescence lines of the covered element, (b) a cross‐ratio between two lines of the elements in the two layers, and (c) the ordinary partial least squares (PLS) regression method. In all cases, the curves obtained could be used for the quantitative determination of the thickness. The experimental data followed the theoretical trend even though the values of the attenuation parameters were not always in agreement with the theoretical ones. Comparisons and discussion of the results of the different approaches and also with models in the literature are made. The methods studied were applied to determine the nature of the coating layers of some gilded objects and proved to be suitable for estimating the thickness of gold by providing results that were in good agreement with each other.

show abstract

Section: Resultssupporting

confidence: 72%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Gold‐coating thickness determination on Ag, Cu, Fe, and Pb using a handheld X‐ray instrument

2021

View full text Add to dashboard Cite

show abstract

“…The practice of gilding dates back from antiquity and is still performed until today by means of different techniques, as electrochemical deposition instead of the toxic mercury firegilding (Anheuser, 1997). With the course of time, a wide array of gilding methods has been developed and those most widespread in antiquity were the application of a gold foil (or leaf) to a prepared substrate, mercury gilding, or depletion (Lechtman et al, 1982;Ingo et al, 2013;Pessanha et al, 2019b). The method chosen also depends on the type of substrate used, which varies from leather, plaster and wood to metals (Cesareo, 2003;Eveno et al, 2014;Tortora et al, 2014;Biocca et al, 2016;Shabunya-Klyachkovskaya et al, 2017;Iorio et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Differential X-Ray Attenuation in MA-XRF Analysis for a Non-invasive Determination of Gilding Thickness

et al. 2020

View full text Add to dashboard Cite

When investigating gilded artifacts or works of art, the determination of the gilding thickness plays a significant role in establishing restoration protocols or conservation strategies. Unfortunately, this is done by cross-sectioning the object, a destructive approach not always feasible. A non-destructive alternative, based on the differential attenuation of fluorescence radiation from the sample, has been developed in the past years, but due to the intrinsic random nature of X-rays, the study of single or few spots of an objects surface may yield biased information. Furthermore, considering the effects of both porosity and sample inhomogeneities is a practice commonly overlooked, which may introduce systematic errors. In order to overcome these matters, here we propose the extrapolation of the differential-attenuation method from single-spot X-ray fluorescence (XRF) measurements to macro-XRF (MA-XRF) scanning. In this work, an innovative algorithm was developed for evaluating the large amount of data coming from MA-XRF datasets and evaluate the thickness of a given overlapping layer over an area. This approach was adopted to study a gilded copper-based buckle from the sixteenth to seventeenth century found in Rome. The gilded object under investigation was also studied by other analytical techniques including scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). Previous results obtained from SEM-EDS were used to confront the data obtained with the proposed methodology and validate it. MA-XRF elemental distribution maps were fundamental in identifying and choosing sampling areas to calculate the thickness of the gilding layer, avoiding lead islands present in the sample that could negatively influence the results. Albeit the large relative standard deviation, the mean thickness values fell within those found in literature and those obtained from previous studies with SEM-EDS. Surface fissure has been found to deeply affect the results obtained, an aspect that is often disregarded.

show abstract

“…Portable Energy Dispersive X-ray Fluorescence (pXRF) is one of the most appropriate techniques in metallic archaeological piece characterization in laboratories or in situ at museums. It can be used for alloy composition determination, for gilded objects thickness evaluation, as well as in provenance studies [26,27,28,29,30] .…”

Section: Introductionmentioning

confidence: 99%

X‐ray fluorescence spectroscopy and Monte Carlo simulation for quantitative characterization of Bolivian pre‐Hispanic golden artefacts

et al. 2020

View full text Add to dashboard Cite

The quantification of archaeological artefacts with X-ray Fluorescence is quite complex because it demands some calibration procedure. It is also rather more challenging when the customization of the portable equipment for in situ measurements is required. The objective of this study was to introduce a quantitative method by performing a calibration curve for a ternary gold alloy (Au, Ag and Cu). Fast Monte Carlo simulation combined with in situ portable XRF (pXRF) measurements in order to circumvent the calibration requirement using standard reference materials was used. Measurements with a laboratorymade equipment were taken from a set of 16 pre-hispanic gold alloy artefacts of a collection from the Museo Nacional de Etnografia y Folklore, La Paz, Bolivia. The spectra simulation was conducted with the XMI-MSIM software. The results demonstrated that the combined use of pXRF measurements and spectra simulation via Monte Carlo is a feasible method for gold alloy quantification. In the examined samples, the Cu content was below 5% and for Au it ranged from 13 to 100%. Moreover, some peculiarities of the artefacts archaeological context were discussed.

show abstract

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

Cited by 23 publications

References 26 publications

Gold‐coating thickness determination on Ag, Cu, Fe, and Pb using a handheld X‐ray instrument

Gold‐coating thickness determination on Ag, Cu, Fe, and Pb using a handheld X‐ray instrument

Differential X-Ray Attenuation in MA-XRF Analysis for a Non-invasive Determination of Gilding Thickness

X‐ray fluorescence spectroscopy and Monte Carlo simulation for quantitative characterization of Bolivian pre‐Hispanic golden artefacts

Contact Info

Product

Resources

About