Quantitative X-ray Fluorescence Research Articles

Heat-resistant concretes based on cement binders and waste from the metallurgical industry

The main direction of the development of heat-resistant concrete production is the use of new materials, ensuring mechanization and industrialization of construction, increasing the performance characteristics of refractory compositions, reducing material consumption, introducing waste-free technologies in the production of concrete with increased physical and mechanical characteristics under prolonged exposure to high temperatures on cement binders and waste from the metallurgical industry and reducing environmental pollution. A significant environmental impact on the environment is exerted by large-tonnage technogenic waste produced by JSC «Aluminum of Kazakhstan» – bauxite sludge obtained by processing bauxite into alumina containing 42.7% Fe2O3. The prospects of its application as a filler in heat-resistant concretes are considered, which makes it possible to increase the physico-mechanical and thermal characteristics. The composition and properties of this waste and the change in the properties of heat-resistant concrete during the introduction of filler have been studied. Reactive alumina has been studied, which is 99.9% submicron alumina with a very low content of Na2O oxide. It is shown that the properties of concrete change after the introduction of iron-containing waste in the amount of 5% and reactive alumina – 37.5% and 38.8%. Their volumetric weight, control strength, and other properties are increased. The improvement of physical, mechanical, and thermal characteristics depends on the structure and neoplasms in the obtained samples. Samples of heat-resistant concrete were analyzed using electron probe X-ray spectral qualitative and quantitative microanalysis and X-ray fluorescence spectrometry and it was shown that the iron-alumina waste contributes to the compaction of the structure due to its resistance to delamination and has increased fluidity at low humidity in the cementing mass. For further investigation of the physical-thermal characteristics, depending on the structure and neoplasms in the obtained samples, a petrographic method using a polarization microscope in transmitted and reflected light is required.

Quantitative X-ray fluorescence micro-analysis of wood samples and visualization of tree rings

The following paper describes the quantitative analysis of wood samples of black pine (Pinus nigra) using a benchtop Micro X-ray Fluorescence (μXRF) device for elemental analysis and surface scanning. Calibration of the device for quantitative elemental analysis and local density measurements of wood was performed by utilizing characteristic X-ray line intensities and backscattered radiation intensities. The influence of a variable wood density and matrix composition on X-ray spectra were studied with Monte Carlo calculations. The Monte Carlo model was validated with a set of reference materials possessing known compositions and densities. It has been demonstrated that Monte Carlo simulations with the MCNP code, along with, only one reference material are required for the quantitative XRF analysis. The backscattered radiation in the XRF spectra can be used for simple recognition of individual tree rings and their corresponding shapes.

Comparison of Different Methods for Evaluating Quantitative X-ray Fluorescence Data in Copper-Based Artefacts

Handheld X-ray Fluorescence devices (HH-XRF) have given archaeologists and conservators the opportunity to study a wide range of materials encountered in their work with great accessibility and flexibility. The investigation of copper-based artefacts is a frequent application of these instruments in the field of cultural heritage as it gives direct and rapid quantitative results that can provide very important information about them, such as their fabrication technology. This paper discusses the comparison of quantitative results, obtained by a commercial handheld XRF device “Bruker Tracer 5g” on certified standards, compositionally significant in copper-based alloys of interest in the field of cultural heritage. The measured elemental concentrations were derived using three different calibrations, which were examined for their accuracy. Two of them were based on the empirical coefficients approach, performed by the built-in calibration/software (copper alloy calibrations provided by Bruker manufacturer and the Bruker EasyCal software), while the third one was performed off-line by processing the spectra with an independent fundamental parameters (FP) software (PyMca version 5.9.2., a X-ray fluorescence analysis software developed at the European Synchrotron Radiation Facility). The results highlight that although HH-XRF devices simplify data collection, for optimal quantitative results, the correct choice of analysis conditions and calibration method still requires a detailed understanding of the principles of X-ray spectrometry.

Liposome biodistribution mapping with in vivo X-ray fluorescence imaging.

Lipid-based nanoparticles are organic nanostructures constituted of phospholipids and cholesterol, displaying high in vivo biocompatibility. They have been demonstrated as effective nanocarriers for drug delivery and targeting. Mapping liposome distribution is crucial as it enables a precise understanding of delivery kinetics, tissue targeting efficiency, and potential off-target effects. Recently, ruthenium-encapsulated liposomes have shown potential for targeted drug delivery, photodynamic therapy, and optical fluorescence imaging. In the present work, we design Ru(bpy)3-encapsulated liposomes (Ru-Lipo) empowering optical and X-ray fluorescence (XRF) properties for dual mode imaging and demonstrate the passivation role of liposomes over the free Ru(bpy)3 compound. We employ whole-body XRF imaging to map the in vivo biodistribution of Ru-Lipo in mice, enabling tumor detection and longitudinal studies with elemental specificity and resolution down to the sub-millimeter scale. Quantitative XRF computed tomography on extracted organs permits targeting efficiency evaluations. These findings highlight the promising role of XRF imaging in pharmacokinetic studies and theranostic applications for the rapid optimization of drug delivery and assessment of targeting efficiency.

Analysis of insecticides in long-lasting insecticidal nets using X-ray fluorescence spectroscopy and correlation with bioefficacy

BackgroundLong-lasting insecticidal nets (LLINs) are a key vector control tool used for the prevention of malaria. Active ingredient (AI) measurements in LLINs are essential for evaluating their quality and efficacy. The main aim of the present study was to determine the utility of X-ray fluorescence (XRF) spectroscopy as a suitable field-deployable tool for total AI quantification in LLINs.MethodsNew and unused LLIN samples containing deltamethrin (PermaNet® 2.0, n = 35) and alpha-cypermethrin (SafeNet®, n = 43) were obtained from batches delivered to Papua New Guinea (PNG) for mass distribution. Insecticides were extracted from the LLINs using a simple extraction technique and quantified using liquid chromatography mass spectrometry (LC-MS). The LC-MS results were correlated with XRF spectroscopy measurements on the same nets. Operators were blinded regarding the type of net. Bioefficacy of the LLIN samples was tested using WHO cone bioassays and test results were correlated with total AI content.ResultsThe results indicate correlation between quantitative XRF and LC-MS. Interestingly, the total AI content was negatively correlated with bioefficacy in PermaNet® 2.0 (especially in recently manufactured nets). In contrast, AI content was positively correlated with bioefficacy in SafeNet®. These results indicate that the chemical content analysis in predelivery inspections does not always predict bioefficacy.ConclusionXRF is a promising field-deployable tool for quantification of both deltamethrin- and alpha-cypermethrin-coated LLINs. Because total AI content is not always a predictor of the efficacy of LLINs to kill mosquitoes, bioefficacy measurements should be included in predelivery inspections.

Synchrotron-based X-ray fluorescence microscopy mapping the ionome of a toxic freshwater cyanobacterium

Harmful algal blooms (HABs) pose a major environmental concern across the globe. In abundance, cyanobacteria, or so-called green-blue algae can produce extremely dangerous cyanotoxins that harm humans and animals. This study focused on the mapping and distribution of intracellular macro-and micronutrients of the wide-spread freshwater cyanobacteria Microcystis aeruginosa (M. aeruginosa). Towards a better understanding of trace metal uptake and homeostasis throughout the cell cycle, we quantitatively mapped the spatial distribution of the elements P, K, Fe, Ca, Zn, Mn, and Cu across the ultrastructure of frozen-hydrated single cells using state-of-the-art X-ray nanofluorescence imaging at the Advanced Photon Source (APS) at Argonne National Laboratory. Bulk cellular nutrient and trace metal content correlated well with the total intracellular elemental content in individual cells obtained by quantitative synchrotron X-ray fluorescence measurements. Multi-dimensional mappings showed P and K atoms colocalized as discrete semicircular hotspots that were analyzed with respect to their stoichiometry. Elevated Cu and Ca concentrations were detected along division plane of cells. P and K were found to have similar spatial elemental distribution with about 65% and 69% of the total cellular P and K, respectively, located at the hotspots. The P and K colocalization were refined further using nanotomography, showing a K envelope surrounding the P core. Inorganic P and organic P compounds were specified using solution-state 31P nuclear magnetic resonance (NMR) spectroscopy from M. aeruginosa. Of the total extracted P determined by 31P NMR spectroscopy, 47% were found to be nucleotides while only 11% were polyphosphates. Multimodal X-ray imaging provides a better understanding of intracellular biochemical processes in cyanobacteria, helping us monitor and combat an emerging environmental threat.

Evaluation of quantitative synchrotron radiation micro-X-ray fluorescence in rice grain.

Concentrations of nutrients and contaminants in rice grain affect human health, specifically through the localization and chemical form of elements. Methods to spatially quantify the concentration and speciation of elements are needed to protect human health and characterize elemental homeostasis in plants. Here, an evaluation was carried out using quantitative synchrotron radiation microprobe X-ray fluorescence (SR-µXRF) imaging by comparing average rice grain concentrations of As, Cu, K, Mn, P, S and Zn measured with rice grain concentrations from acid digestion and ICP-MS analysis for 50 grain samples. Better agreement was found between the two methods for high-Z elements. Regression fits between the two methods allowed quantitative concentration maps of the measured elements. These maps revealed that most elements were concentrated in the bran, although S and Zn permeated into the endosperm. Arsenic was highest in the ovular vascular trace (OVT), with concentrations approaching 100 mg kg-1 in the OVT of a grain from a rice plant grown in As-contaminated soil. Quantitative SR-µXRF is a useful approach for comparison across multiple studies but requires careful consideration of sample preparation and beamline characteristics.

The applicability of Fourier transform infrared microspectroscopy for correction against matrix effects in X-ray fluorescence microimaging of tissues

X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) microscopy techniques are now considered popular for rapid and label-free complementary spectrochemical analysis of chemical elements and molecular systems in biological specimens. The morphological heterogeneity but also the inhomogeneities associated with the thickness/density of biological samples demonstrate challenges for the quantitative XRF microimaging. Therefore, in the present work, we proposed for the first time the application of the total absorbance under the FTIR spectra as a mass surface correction procedure for two-dimensional (2D) XRF microimaging of tissues. We also evaluated the equivalence of the developed correction method based on total absorbance of FTIR spectra with the proposed approaches based on incoherent scattering of primary X-rays as well as on the membrane Si–Kα transmission signal, on the example of selected rat organ tissues. Thin cryo-sections taken from various organs of Wistar rats were deposited on silicon nitride membranes (Si3N4). The FTIR microscopy studies were performed to collect infrared absorption spectra, used then for the determination of total absorbance values in the selected areas of tissue samples. In turn, hard X-ray imaging based on synchrotron radiation allowed the determination of characteristic radiation intensities of the elements detectable from the tissue, as well as the characteristic radiation of the membrane Si and incoherently scattered X-ray photons (Compton scattering). The latter served as correction factors for the surface mass of the sample alongside the FTIR total absorbance. The qualitative and quantitative analyses showed a high agreement between the results of elemental surface mass correction using total absorbance under FTIR spectra of tissues with those obtained using surface mass correction factors determined directly from XRF spectra. Therefore, the proposed procedure is a good alternative in cases where the surface mass effect of the sample cannot be eliminated based on the information provided directly by the XRF spectrum, as in the case of using polymer films as sample support. We have also proposed a procedure for synchronizing SRXRF and FTIR images, not limited to visual inspection of imaging/mapping data, but also enabling quantitative analysis. We found that the total absorbance determined from FTIR spectra can be successfully used as a correction factor for eliminating the surface mass effect in XRF microimaging of thin freeze-fried tissues and therefore to obtain the surface mass-independent elemental quantities. The proposed approach for 2D-FTIR-XRF analysis can also be a powerful and versatile tool for fostering a correlation and co-localization analysis to search for common distribution patterns between molecular arrangements and chemical elements.

Abstract TP92: Early Hyperacute Ion Dysregulation Following A Temporary Large Vessel Occlusion Stroke

Introduction: Ion dysregulation is a hallmark of energy failure after onset of ischemic stroke. To better understand the nature of the ion concentration changes in the early hyperacute phase after stroke onset we have quantitatively imaged the trace element distribution in the stroke lesion territory after a 30-minute temporary large vessel occlusion stroke. Methods: A temporary large vessel occlusion stroke was generated with the middle cerebral artery occlusion (MCAO) mouse model (insertion of an occluding filament via the ECA) with reperfusion after 30 minutes (occluding filament withdrawn). C57BL/6 mice (5 per time point) were euthanized at 5-, 30-, 60-, 90-, and 120-minutes post reperfusion. Shams included all surgical procedures, however the occluding filament was withdrawn immediately after insertion. Heads were immediately frozen post mortem and sectioned for trace element mapping. Quantitative X-ray fluorescence microscopy was performed at the Stanford Synchrotron Radiation Lightsource. Results: Loss of potassium is observed throughout the affected tissue at all post-reperfusion time points, with most of the initial loss occurring in the 30-minutes prior to reperfusion. Loss of essential zinc began to be observed 1-hour post reperfusion. No significant elevations in chlorine or calcium were observed during the early hyperacute phase. At subsequent post reperfusion time points the lesion (as defined by diminished potassium) grew steadily for 90-minutes. After 90-minutes post reperfusion some lesions demonstrated a distinct pattern consistent with a central infarct core surrounded by an ischemic penumbra. Conclusions: At all early hyperacute time points the stroke lesion demonstrated on-going potassium dysregulation, despite reperfusion. The loss of potassium was a bulk phenomenon in the tissue. Potassium is essential for maintenance of neuronal membrane potential and therefore function. Restoration of normal blood flow is insufficient to protect the brain from the enduring reduction in vital potassium levels or expansion of the region of ion dysregulation. The lack of available potassium within the affected tissue may hinder recovering neuronal cells from restoring action potentials, even after tissue perfusion is restored.

Uncertainty of Quantitative X-ray Fluorescence Micro-Analysis of Metallic Artifacts Caused by Their Curved Shapes.

This paper summarizes the effects of irregular shape on the results of a quantitative X-ray fluorescence (XRF) micro-analysis. These effects become relevant when an XRF analysis is performed directly on an investigated material. A typical example is XRF analyses of valuable and historical objects whose measurements should be performed non-destructively and non-invasively, without taking samples. Several measurements and computer simulations were performed for selected metallic materials and shapes to evaluate the accuracy and precision of XRF. The described experiments and the corresponding Monte Carlo simulations were related to the XRF device designed and utilized at the Czech Technical University. It was found that the relative uncertainty was typically about 5-10% or even higher in quantitative analyses of minor elements due to irregular shapes of surfaces. This must be considered in cases of the interpretation of XRF results, especially in the cultural heritage sciences. The conclusions also contain several recommendations on how to measure objects under hard-to-define geometric conditions with respect to reduction in the surface effect in quantitative or semi-quantitative XRF analyses.

Quantitative x-ray fluorescence imaging system for non-destructive 3D tumor histology.

An in-house dual-modality x-ray fluorescence tomography (XFT) and x-ray computed tomography (XCT) system was developed to quantify iodine contrast distribution through the whole tumor volume ex vivo. The quantitative XFT was calibrated with water phantoms containing iodine solutions of various concentrations (0.0175-1.4 wt.%). The vasculature distribution was reflected by the iodine perfusion, which was validated with histology. This technique may open a new, to the best of our knowledge, route to the non-destructive three-dimensional-imaging-based histological analysis of tumor samples.

Quantitative laser-based x-ray fluorescence and particle-induced x-ray emission

In this work, we demonstrate the feasibility of quantitative laser-based x-ray fluorescence (XRF) combined with particle-induced x-ray emission (PIXE) (called XPIF for x-ray and particle-induced fluorescence) spectroscopy analysis for elemental composition in solid samples. A multi-hundred TW laser system accelerated protons and produced x-rays that were impinging on solid samples, inducing characteristic line emissions of the elements contained in the material. The x-ray yield obtained from the characteristic emissions for each element can be related to its mass concentration using both the thick PIXE and thick XRF formalism. This is performed by using of an iterative numerical procedure. We tested the validity of our method on three homogeneous metallic materials, stainless steel, bronze and brass. The mass proportions of these samples retrieved by our analysis (XPIF) is within the errors bars compared with a commercial energy dispersive x-ray spectrometer.

Introducing the BRICC (Bricks and rocks for Instruments’ ceramic calibration) sets: Open-source calibration materials for quantitative X-ray fluorescence analysis

Here we introduce a set of well-characterized historical brick and geological specimens intended to aid the calibration of portable XRF (pXRF) instruments for archaeological ceramics. Known as the BRICC (Bricks and Rocks for Instruments’ Ceramic Calibration) sets, each of the ten matched sets consists of 20 specimens mounted in epoxy discs: 12 bricks and 8 geological specimens to use for calibration. Additionally, a certified reference material – a shale standard measured by 85 labs – is included with each set to assess the resulting accuracy, and a high-purity silica blank is included to check for spectral interferences or other calibration issues. The BRICC sets provide an open-source alternative to pXRF calibration approaches that are proprietary, were devised for oil shales instead of ceramics, and/or rely on expensive and often unavailable certified standards. A set can be tested at Yale or borrowed following loan policies of the Yale Peabody Museum. Publishing all information for the historical bricks and geological specimens – from their origins to the data used to derive the recommended values – fulfills the requirements of scientific transparency. Ultimately, these sets are intended and designed as a means (1) to meet (and exceed) experts’ practices regarding accuracy, reproducibility, and scientific transparency when analyzing ceramics using pXRF and (2) to reduce siloed production of knowledge within established laboratories and, hence, facilitate integration of more diverse perspectives into elemental studies of archaeological ceramics.

Сарнилын пикийг ашигласан тулгуур параметрын арга

Instead of using the complete set of fundamental parameters for solving matrix effects in quantitative energy dispersive x-ray fluorescence analysis, some of them, such as excitation and detection efficiency and dependence of Compton and Reylaeigh scattered intensities on sample composition, were determined from a set of standards such as chemical compounds and pure elements. In this way all fundamental parameters except mass absorbtion coefficients were removed from the calculation procedure, which results in a much simpler formalism. the computer program based on this principle and described in this paper is relatively simple and, can run even on small computers, while the overall error can be kept in the range of few percent.

A Nanostructured Cu(II) Coordination Polymer Based on Alanine as a Trifunctional Mimic Enzyme and Efficient Composite in the Detection of Sphingobacteria.

This research raises the potential use of coordination polymers as new useful materials in two essential research fields, allowing the obtaining of a new multiartificial enzyme with the capacity to inhibit the growth of bacteria resistance. The fine selection of the ligands allows the design of a new 2D coordination polymer (CP), with the formula [Cu2(IBA)2(OH2)4]n·6nH2O, by the combination of Cu (II) as the metal center with a pseudoamino acid (H2IBA = isophthaloyl bis β-alanine). Quantitative total X-ray fluorescence (TXRF) analyses show that the obtained CP can gradually release Cu (II) ions. Additionally, this CP can be nanoprocessed and transformed into a metal-organic gel (MOG) by using different Cu (II) salt concentrations and the application of ultrasounds. Considering its nanometric dimensions, the slow Cu (II) release and its simple processability, its performance as an artificial enzyme, and its antibacterial ability were explored. The results obtained show the first nanocoordination polymer acting as an artificial multienzyme (peroxidase, catalase, and superoxodismutase) exhibiting antibacterial activity in the presence of hydrogen peroxide, with selective behavior for three bacterium strains (S. spiritovirum, A. faecales, and B. cereus). Indeed, this CP shows a more robust inhibition capacity for Sphingobacterium. Going beyond that, as there are no comfortable and practically clinical tests capable of detecting the presence of Sphingobacteria, the compound can be easily embedded to form moldable gelatin that will facilitate the handling and low-cost commercial kits.

Influence of soil sample grain size on energy dispersive X-ray fluorescence analysis: a comparative study case with three spectrometers

This study aims at evaluating the particle size influence on the quantitative Energy Dispersive X-ray Fluorescence data of tropical soils, as well as evaluating the results trueness and precision using different statistical approaches. These objectives were conducted in three spectrometers, a benchtop one, and two portable ones. Certified reference materials were employed in calibration and trueness evaluation. Soil samples were collected, grounded and sieved in particle sizes: macerated (>2 mm), <2, <0.7, <0.3, <0.125, and <0.06 mm. The three spectrometers had different performances and lack of trueness for Potassium and Zinc in the Lab-made spectrometer. Regarding the grain size parameters, the spectrometers responded in different ways. It was identified that the best soil grain size condition for one of the portable spectrometers was <0.06 mm, while for the benchtop and for the other portable spectrometer the best soil grain size was <0.125 mm. In summary, the soil grain size affected the quantitative results in Energy Dispersive X-ray Fluorescence measurements, but it depends on the sensitivity of each spectrometer and the element of interest.

PolyCO in XRF analysis: Fundamental Parameter Method applied for Japanese Buddhist scroll studies

The quantitative evaluation of chemical elements from X-ray Fluorescence (XRF) analysis still remains a strong hurdle in X-ray Spectrometry, mainly due to significant matrix effects involved in the processes. The Fundamental Parameter Method (FPM) is a valid tool for the calculation of analyte concentration unless the primary source comes from a Synchrotron Radiation facility or the experimental design is based on a confocal layout. The approximation of an infinitely thin sample represents a feasible way to apply the FPM approach along with dedicated X-ray optics implemented in the XRF apparatus to improve the performance of the primary beam (and also of the fluorescence signal reaching the detector). This is routinely available at the XLab Frascati of INFN-LNF thanks to the ”Rainbow X-ray” (RXR) facility, the μXRF station opened to users and optimized for most of X-ray analytical research fields. The basic principle of the station is in the use of various geometrical combinations of polycapillary optics for X-ray beam shaping (focusing/collimation) applied to specially designed laboratory units. The flexible RXR layout allows investigating specimens of the dimensions ranging from several millimeters up to half meter and weighting up to several tens of kilograms with the main advantage of having a detection system able to work separately both at high and low X-ray energies. The aim of the present work is to show the results obtained in quantitative XRF analysis by applying the FPM approach to the RXR experimental layout in a study of the pigments covering two different Japanese scrolls, n.142 838 (also known as Engi Jizo Emakimono) and n. 142 846, coming from the private Ragusa Collection presently stored at Pigorini Museum in Italy.

More than the Eye Can See: Shedding New Light on SARS-CoV-2 Lateral Flow Device-Based Immunoassays.

Containing the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been an unprecedented challenge due to high horizontal transmissivity and asymptomatic carriage rates. Lateral flow device (LFD) immunoassays were introduced in late 2020 to detect SARS-CoV-2 infection in asymptomatic or presymptomatic individuals rapidly. While LFD technologies have been used for over 60 years, their widespread use as a public health tool during a pandemic is unprecedented. By the end of 2020, data from studies into the efficacy of the LFDs emerged and showed these point-of-care devices to have very high specificity (ability to identify true negatives) but inadequate sensitivity with high false-negative rates. The low sensitivity (<50%) shown in several studies is a critical public health concern, as asymptomatic or presymptomatic carriers may wrongly be assumed to be noninfectious, posing a significant risk of further spread in the community. Here, we show that the direct visual readout of SARS-CoV-2 LFDs is an inadequate approach to discriminate a potentially infective viral concentration in a biosample. We quantified significant immobilized antigen–antibody-labeled conjugate complexes within the LFDs visually scored as negative using high-sensitivity synchrotron X-ray fluorescence imaging. Correlating quantitative X-ray fluorescence measurements and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) determined numbers of viral copies, we identified that negatively scored samples could contain up to 100 PFU (equivalent here to ∼10 000 RNA copies/test). The study demonstrates where the shortcomings arise in many of the current direct-readout SARS-CoV-2 LFDs, namely, being a deficiency in the readout as opposed to the potential level of detection of the test, which is orders of magnitude higher. The present findings are of importance both to public health monitoring during the Coronavirus Disease 2019 (COVID-19) pandemic and to the rapid refinement of these tools for immediate and future applications.

To be or not to be local: a provenance study of archaeological ceramics from Shahr-i Sokhta, eastern Iran

Findings from the archaeological site of Shahr-i Sokhta in eastern Iran include a wide range of undecorated, monochrome, and polychrome ceramics with gray, red, and buff-colored bodies that date back to a period spanning from 3200 to 1800 B.C.E. Given the large number and variety of ceramics unearthed from Shahr-i Sokhta, the provenance of these wares has remained a subject of controversy. Based on compositional data obtained from quantitative wavelength dispersive X-ray fluorescence (WDXRF) spectroscopy studies and petrographic observations, findings from this study provide information that can be used to determine whether the ceramics from Shahr-i Sokhta were manufactured locally or were imported from elsewhere. We show here that the chemical components of a large group of ceramics with gray, red, and buff-colored bodies are similar to those found in local clay sources and kiln wasters, suggesting local production of these wares. However, one group of red and gray-colored wares demonstrated entirely different chemistry, suggesting a different origin. In support of the quantitative WDXRF data, petrofabric analysis of the first group of buff, gray, and red wares revealed poorly sorted basaltic clasts similar to those found randomly distributed in the matrix of local clays. By contrast, the non-local gray and red wares exhibited fine-grained clay bodies with sorted distribution of fine-grained quartz within the clay matrix.

On, under and beneath the patina: Evaluation of micro energy dispersive X-ray fluorescence quantitative data on the classification of archaeological copper alloys

A series of quantitative micro X-ray fluorescence (μ-XRF) analyses was performed on a) corroded surface, b) stripped-patina area and c) polished cross section of twenty-five archaeological copper alloys from Iran in order to check the viability of quantitative XRF data for the classification of ancient copper alloys. The limits of detection and quantification and, also, the precision and accuracy of the analytical data were measured using twelve certified reference materials (CRM). The compositional data obtained through these three approaches were statistically evaluated comparing with the compositional data on the same samples obtained by the inductively coupled plasma – optical emission spectroscopy (ICP-OES). We demonstrated that the corroded surfaces are depleted in Ni and Zn and enriched in Pb, Sn and As. Also, we suggest that although μ-XRF quantitative compositional data collected from the corroded surfaces may result in misleading information, the areas with the lowest Sn concentration may represent the closest compositional data to the absolute quantity of Cu, Zn, As and Pb in ancient copper alloys. Moreover, it is shown that the quantitative μ-XRF data obtained from the stripped-patina surface and those from the polished cross sections are comparable with the ICP-OES compositional data and can be confidently used for determining the diversity and technology of ancient copper alloys.