Portable Energy Dispersive X-ray Fluorescence Research Articles

Comparison of Quantitative and Qualitative EDXRF Analysis for Provenance Study of Archaeological Ceramics

The most common scientific analysis of archaeological ceramics aims to determine the raw material source and/or production technology. Scientists and archaeologists widely use XRF-based techniques as a tool in a provenance study. After conducting XRF analysis, the results are often analyzed using multivariate analysis in addition to interpretation and conclusions. Various multivariate techniques have already been applied in archaeological ceramics provenance studies to reveal different raw material sources, identify imported pieces, or determine different production recipes. This study aims to evaluate the results of multivariate analysis in the provenance study of ceramics that belong to three cultures that settled in the same area during various prehistoric periods. Portable energy-dispersive X-ray fluorescence spectrometry (pEDXRF) was used to determine the elemental composition of the ceramic material. The ceramic material was prepared in two different ways. The ceramic body material was ground into powder, homogenized, and then pressed into tablets. After that, the same fragments are polished in suitable places. Quantitative and qualitative analyses were performed on the tablets and polished pieces. The results were subjected to both unsupervised and supervised multivariate analysis. Based on the results, it was concluded that qualitative analysis of the well-prepared shards’ surface using EDXRF spectrometry could be utilized in provenance studies, even when the ceramic assemblages were made of similar raw materials.

Application of handheld/portable spectroscopic tools to the identification, inner stratigraphy and mapping of archaeological metal artefacts

Field handheld/portable instrumentations, such as in-situ geochemical analyzers, have the potential to assist efficiently targeted geochemical archaeometry campaigns in detecting and quantifying specific elements. Non-destructive portable energy dispersive x-ray fluorescence and micro-destructive handheld laser-induced breakdown spectroscopy (LIBS) instrumentation were utilized to investigate the elemental composition, internal stratigraphy by depth profiling and microscale compositional mapping of five copper and two iron alloy artefacts collected from various ancient graves in the Minervino Murge area, Apulia, Italy. The primary elements identified by both techniques included Cu, Sn and Pb in copper alloys, and Fe with minor amounts of Cu and Pb in iron alloys. Furthermore, the elements Al, Ca, Si, Mg, Na and K, mostly originated from soil contamination, and the trace elements Sb, Ni and Zn were detected. The satisfactory performance of both techniques was assessed by their capacity to provide reproducible elemental composition data. Finally, the depth profile and mapping achieved by LIBS contributed to understanding the metal processing and history of the objects studied, so confirming both techniques to be robust analytical tools in outdoor archaeology and archaeometry campaigns.

Integrated Investigations of Painting Materials in the Sasanian City of Ardaxšīr Khwarrah, near Firuzabad (Southern Iran)

Ancient Ardaxšīr Khwarrah, today known as Shahr-e Gur, situated near the modern town of Firuzabad in Fars, Iran, holds historical significance as the inaugural capital city of the Sasanian Empire. During archaeological excavations conducted in 2005 by an Iranian–German team directed by Mas‘oud Azarnoush and Dietrich Huff, a mud-brick complex was uncovered, revealing a remarkably well-preserved stretch of wall painting and a polychrome painted floor. The discovery prompted the hypothesis of a potential funerary context dating back to the Sasanian period. Both the wall painting and painted floor have suffered extensive deterioration attributed to the environmental conditions of the archaeological site, which was inscribed on the UNESCO World Heritage List in 2020. To address the urgent need for preservation and further understanding of the site’s artistic and structural elements, an emergency diagnostic project was initiated. Non-invasive investigations were carried out on the wall and floor by optical digital microscopy and portable energy-dispersive X-ray fluorescence. Additionally, representative minute samples underwent analysis through various techniques, including micro-X-ray fluorescence, polarised light microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, micro-Raman spectroscopy, micro-Fourier Transform Infrared Spectroscopy, gas chromatography-mass spectrometry and pyrolysis coupled with gas chromatography-mass spectrometry. The palette of the floor and mural paintings were identified to contain red and yellow ochres, lead-based pigments, carbon black and bone white. The unexpected presence of Egyptian blue mixed with green earth was recognised in the green hues of the wall painting. The detection of protein material in both the wall painting and polychrome floor indicates the use of “a secco” technique, thereby shedding light on the artistic practices employed in Ardaxšīr Khwarrah.

X-ray fluorescent method for the analysis of trace elements in bio-materials with correction of the matrix effect.

A method for correcting the matrix effect by measuring the intensity of fluorescent radiation and its absorption by the sample material in the same x-ray optical scheme is proposed. The use of a complex secondary Ag-Ge emitter as a primary radiation source provides a low detection limit for a wide range of chemical elements from Ca (Z = 20) to Mo (Z = 42) in the K-series and from Cd (Z = 48) to Bi (Z = 83) in the L-series. To measure the absorption, the radiation of an additional secondary emitter is used, of which the wavelengthcan be varied in the range from 0.633 to 3.38 Å, depending on the measured impurity. An example of determining the mass fraction of an impurity in a sample of unknown composition prepared from a mixture of state standard samples of aqueous solutions is given. The x-ray optical scheme was assembled on the basis of a portable Energy Dispersive X-ray Fluorescence(EDXRF) spectrometer. The method is designed to study materials with a base consisting of chemical elements with a low atomic number.

Optimization of pXRF instrumentation conditions and multivariate modeling in soil fertility attributes determination

The increasing global demand for agricultural products, food, and energy requires a sustainable and secure approach to agricultural production. Soil nutrition is vital for enhancing agricultural productivity, and understanding the spatial variability of fertility attributes is crucial in soil fertility prevention. Traditional soil analysis methods are time-consuming, costly, and generate waste. Spectral-analytical techniques, such as energy dispersive X-ray fluorescence (EDXRF) combined with multivariate analysis, offer a faster, cost-effective, and environmentally friendly alternative. This study aimed to optimize measurement conditions for predicting soil fertility attributes using a commercial routine from a portable EDXRF (pXRF) equipment and compare its performance with benchtop EDXRF using Partial Least Squares Regression (PLS) modeling. The data fusion from different measurement conditions using low- and mid-level fusion approaches was explored to evaluate the models' synergy. 364 soil samples at three different depths were used. The study area covers 12 ha of Red Latosol and Red Nitosol. Ten fertility attributes were evaluated: exchangeable macronutrients (Ca2+, Mg2+, and K+), available phosphorus (PM), pH, potential acidity (H + Al), soil organic carbon (SOC), cation exchange capacity (CEC), sum of exchange bases (SB) and base saturation percentage (BSP). The results indicated that the measurement of the three experimental conditions tested is unnecessary, and the data fusion does not significantly improve the model's performance. The use of 15 kV and 12.15 μA without filters provided the best performance results for all attributes simultaneously. By the established RPD ranges, the SOC, CEC, SB, and Ca2+ models were considered very good for quantitative prediction (RPD >2.0), while the K+ and Mg2+ models were considered good for quantitative predictions (1.8 < RPD < 2.0). The PM, pH, BSP, and H + Al models provided fair predictions, which may be used for evaluation and correlation (RPD <1.8). Furthermore, the pXRF optimized condition provided results equivalent to those modeled with benchtop EDXRF data. These results highlight the potential of pXRF as an economical, rapid, and efficient alternative approach to the conventional method, and may provide valuable insight for decision-making related to the use of fertilizers and other soil correction products.

Portable EDXRF spectrometer: determination of linearity, LOD, LOQ, and working range for the analysis of base and precious metals in liquid matrices

Utilizing a portable energy dispersive X-ray fluorescence (EDXRF) spectrometer and certified reference materials, this study aimed to determine the linearity, limit of detection (LOD), limit of quantification (LOQ), and working range of the method for quantitative analysis of base and precious metals in liquid matrices. As the EDXRF method lacks standardization and is highly susceptible to matrix effects, these calculations play a crucial role in the analytical validation process. The obtained R2 values in this study exceeded 0.99, and the residuals exhibited a random distribution pattern. The LOD and LOQ values were determined to be exceptionally low, approaching the resolution limit of the spectrometer. Consequently, our calculations confirmed the analytical validation of the portable EDXRF method for analyzing elements in liquid matrices. The utilization of portable EDXRF equipment in quantitative measurements of elements in liquid matrices represents an innovative approach, unveiling new areas of application for this type of instrument.

Morphological and structural analysis of iron-rich porcelains excavated from the Jian kiln site of Song dynasty.

Iron-rich porcelains generally embrace relatively high iron concentration in the glaze and body, which have an important position in the history of ancient Chinese high-temperature ceramics. The colour and lustre of glaze patterns are closely related to the orientation and order of crystallisation. In this work, three representative types of iron-rich porcelains (persimmon red-glazed sample, oil spot-glazed sample and mirror black-glazed sample) were analysed by portable energy-dispersive X-ray fluorescence (PXRF), optical coherence tomography (OCT), optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RS) to determine the morphology, chemical composition and microstructure. Results showed that layered structure was observed in both persimmon red and oil spot glazes, however with respective thickness. Besides, iron-enriched crystals mostly precipitated on glaze surface. For the persimmon red sample, multilayer microstructure consisting of three sublayers beneath glaze surface was identified. Crystals and dark red substrates were all made of ε-Fe2 O3 , implying that it was fired at a strong reducing atmosphere. But for the oil spot sample, large-scale leaf-shaped crystals were well characteristic of ε-Fe2 O3 , while small snowflake-shaped crystals were assigned to α-Fe2 O3 , indicating that the firing environment was partially reduced. In addition, there was no crystalline layer existing on surface of mirror black-glazed porcelain, and plain black glaze layer was featured by a glassy matrix. The Jian kiln is a famous ancient folk kiln in the southern China that is currently located in Jianyang county of Fujian province. Its production of black-glazed porcelain began in the Tang dynasty (618-907 AD), became prosperous in the Southern Song dynasty (1127-1279 AD), and declined and ended in the Yuan dynasty (1271-1368 AD). Black-glazed Jian tea bowls were perfect for highlighting the rich white tea decoction. The thick and lustrous black glaze of Jian bowls sometimes were featured by streaked or mottled patterns, usually recognised by 'hare's fur (HF)', 'oil spot (OS)', 'partridge spot (PS)' and so on, which were the crystalline markings of iron oxide precipitated during firing in the dragon kiln. Iron oxide acted as a colorant for black-glazed porcelain and, thus, was called as iron-rich porcelain. The unique patterns originated from local iron-enrichment raw materials and firing process, and the locally iron-enriched areas generated due to the supersaturated crystallisation of different iron oxide in the cooling period. It was generally believed that research studies on the crystallographic nature and growth mechanism of surface crystals would provide help for the manufacturing of ancient Chinese glazes. With this aim, three types of iron-rich porcelain excavated from the Jian kiln were selected to further study the forming cause and growth process of glaze patterns using a series of characterisation methods, like portable energy-dispersive X-ray fluorescence (PXRF), optical coherence tomography (OCT), optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RS).

Sumaki Höyük (Batman, Türkiye) Neolitik Yerleşiminde Bulunan Bazalt Parçalarının Çok Perspektifli Jeokimyasal ve Mineralojik Analizi

This study aims to determine the provenance of grinding stone tools unearthed from the Neolithic phases of Sumaki Höyük settlement using a portable Energy Dispersive X-ray Fluorescence Spectrometer (P-EDXRF) and X-ray Diffraction spectrometer (XRD). Sumaki Höyük is located in the Lower Garzan Basin of Batman province, Turkey. The settlement is dated to 9084 - 8123 cal BP. Grinding stone tools in this settlement are usually made of basalt. Albeit at low amounts, limestone was also used in the production of grinding stones. The Lower Garzan Basin, located to the east of Diyarbakır Basin, is surrounded by Mount Kıradağı and Mount Raman to the west and the Garzan and Kentalan Anticlinal to the east with Kıradağı extending in a northwest-southeast direction. The basalt flow occurred in the Quaternary period. Samples collected from different parts of the Neolithic phase of Sumaki Höyük and the Kıradağı basalt flows were analyzed using P-EDXRF to determine their chemical composition. The same samples were also analyzed using XRD to determine their mineral composition. P-EDXRF and XRD analyses reveal that the samples from Sumaki Höyük and Kıradağı are in good accordance with each other. It is therefore understood that the basalt stone tools used in the settlement were taken from the Kıradağı basalts. Data gathered on the characteristics of potential source locations provide an insight into the settlement strategy and mobility of Neolithic communities.

Geochemical fingerprinting of fossils with uncertain stratigraphic provenance: A case study from the Lower Jurassic Nishinakayama Formation (Yamaguchi, Japan)

A fossil without provenance data is problematic because it cannot be placed into meaningful paleoecological and paleobiogeographic contexts. This problem is particularly acute when the fossil is suspected or known to have originated from a formation within which a major interval of biotic and/or paleoenvironmental change has been recognized that could change the paleobiological implications of the taxon in question. Two reptile fossil specimens (a testudinate and a crocodylomorph) preserved within ex situ mudstone cobbles of the Lower Jurassic (Pliensbachian-Toarcian) Nishinakayama Formation in Yamaguchi, Japan exemplify this problem. Both specimens are preserved alongside associated ammonoid fossils that biostratigraphically constrain them to the Toarcian interval of the Nishinakayama Formation, but it is unclear whether their stratigraphic provenance is below, within, or above the interval of the formation that preserves the chemostratigraphic markers of the Toarcian Ocean Anoxic Event (T-OAE, ∼182.5 ​Ma), which were first established at the nearby locality Sakuraguchidani. Herein, we used isotope ratio mass spectrometry and portable energy-dispersive X-ray fluorescence to investigate the geochemistry of sedimentary matrix sampled from each fossil and a new measured stratigraphic section of the Nishinakayama Formation close to where the fossil specimens were found. We interpret a ∼2‰ positive shift in δ13Corg at the base of the section as the recovery of the negative carbon isotope excursion associated with the T-OAE, providing additional evidence of the event from a new locality within the Nishinakayama Formation. Linear discriminant analysis (LDA) of the total geochemical dataset was then used to explore the multivariate separateness of binned intervals of the composite section and predict the provenance of each fossil. The results suggest with 93.33% confidence that both fossils were derived from strata above the T-OAE interval. This predictive method can be applied to any fossil collected ex situ with preserved rock matrix and for which the general provenance is known or suspected.

In-Field Obsidian XRF Analysis of Sites in the Lion Mountain Area and Gallinas Mountains of West-Central New Mexico

ABSTRACT The Gallinas Mountains of west-central New Mexico were home to agriculturalists between ca. a.d. 850 and 1450. Ongoing research of the Lion Mountain Archaeology Project (LMAP) has allowed for in-field analysis of surface obsidian artifacts via portable handheld energy dispersive X-ray fluorescence spectrometry (ED-XRF). Influenced by principles of preservation archaeology and the archaeological repository curation crisis, the LMAP has sought to design and conduct field research to gather the most data with the least amount of impact to sites. Non-destructive in-field analysis via portable handheld ED-XRF subscribes to these goals while also providing answers to significant questions about human behavior. Results show that variable patterns of obsidian source utilization and procurement strategies existed both through time and between contemporaneous populations. These results are indicative of a shifting system of exchange and social interaction between residents of the region and surrounding areas during the Ancestral Pueblo occupation of the area.

Morphology and Structure Characteristics of the Rare Black-Glazed Porcelains Excavated from the Jian Kiln Site of Song Dynasty

Jian tea bowls are greatly appreciated not only due to their thick and lustrous black glazes, but also their exquisite streaked and mottled patterns. Researches on the firing process and colouring mechanism of typical hare’s fur and oil spot Jian glazes have continuously been carried out in the past decades; however, there are few reports about other scarce types of black-glazed porcelains excavated from the Jian kiln site. In this work, we report on a multi-technique analysis of the surface and cross-sectional structure, phase, morphology and chemical composition of three rare types of Jian tea bowls (tea-dust-glazed ware, grey-glazed ware and pearl-glazed ware) combining optical and spectroscopic methods such as optical coherence tomography (OCT), optical microscopy (OM), Portable energy dispersive X-ray fluorescence spectrometry (XRF), laser-Raman spectroscopy (LRS) and scanning electron microscopy coupled with an X-ray energy dispersive spectrometer (SEM-EDS). Results revealed that the tea dust glaze was one high-temperature iron-based crystalline glaze, and its glaze was characterized by a transparent glass matrix; irregular pits completely or partially filled by TiO2; and that ε-Fe2O3 and residual quartz were randomly distributed all over the surface, which produced the appearance of tea-dust. The grey-glazed porcelain was fired at a lower temperature in the dragon kiln than that of the traditional hare’s fur and oil spot samples, its glaze contained some residual quartz, and anorthite crystals showed a serried distribution along the thickness. The pearl-glazed porcelain was fired through a secondary glazing process via artificial stippling quartz powder. This work provides guidance for the firing process of three rare types of Jian wares and has not only scientific but also cultural profound significance, which reveals the features of their historical heritage.

A study by portable X-ray fluorescence (pXRF) of the painting “Still Life with Vase, Plate and Flowers” (1886–1888)

Portable energy-dispersive X-ray fluorescence spectroscopy (pXRF) was employed in the characterization of the pigments present in the painting “Still Life with Vase, Plate and Flowers”, of unknown authorship, but previously attributed to Vincent van Gogh, belonging to the collection of the São Paulo Museum of Art (MASP). In situ pXRF measurements were carried out by means of a portable system in order to provide the museum with a scientific documentation about the materials in the painting. Spectra were taken at different color regions and different hues in the pictorial layer. Some of the materials identified in the painting were chalk and/or gypsum, lithopone, lead white, zinc white, bone black, barium yellow, chrome yellow, yellow ochre, chrome green, Prussian blue, cobalt blue, vermilion and red earth. Besides that, it was possible to suggest the use of a lake pigment. The pigments whose use is suggested by this work are in total agreement with those available to European artists in the end of the 19th century.

In Situ Investigation of the Medieval Copper Alloy Door in Troia (Southern Italy)

This work describes experimental results concerning the chemical composition of the alloy patina and inlays from the medieval copper alloy door of the cathedral of Troia (southern Italy), dating back to 1127 CE. The analyses were conducted in situ with no sampling or sample preparation required, using a portable energy-dispersive X-ray fluorescence (ED-XRF) instrument. The compositional results show that the two door leaves were made using a binary alloy of copper and lead, while the nails, lion protomes, and handles have a different chemical composition. Moreover, the analyses revealed uniform concentrations of chlorine, probably due to cleaning treatments during the restoration. It is important to emphasise that the obtained results are the only ones related to this valuable masterpiece analysed.

Portable x-ray fluorescence calibrations: Workflow and guidelines for optimizing the analysis of geological samples

The use of portable Energy Dispersive X-Ray Fluorescence (pXRF) spectrometers has exploded within the last decade for e.g., environmental, geological, and archaeological field research. Producing reliable geochemical data using a pXRF is a challenging process that requires the development of dedicated and matrix-matched empirical calibrations. Although a large field of applications, several research papers are still published using unquantified pXRF data, using manufacturers' built-in calibrations unsuitable for targeted rocks, or interpreting chemical concentrations without checking the limit of quantification of the pXRF spectrometer and its calibration model. In this paper, we present a general workflow for building an empirical calibration model for a pXRF spectrometer, from choosing reference materials to validating calibration's efficiency and quantifying its limit of quantification. We also compare the geochemical results on a sedimentary and an igneous rocks suite obtained from thirty-two calibration models that were built using different software available, including a simple homemade spreadsheet, the EasyCal calibration software, a free and open-source calibration app named CloudCal, and the built-in GeoMining and GeoExplorer calibrations provided by Bruker manufacturer on the Tracer 5 pXRF. This decoupled approach allows (i) to explore the pros and cons of each calibration model and determine which empirical calibration model brings the most accurate chemical concentration for a sedimentary and an igneous rock suite, (ii) to weigh the impact of each calibration parameter (type of regression line, spectral interferences, normalization, influence coefficients, multiple conditions of excitation and acquisition) on the accuracy of geochemical concentrations on rock samples and (iii) to bring innovative tools to assess the limits of quantification of a newly built calibration model.

Investigation of red substances applied to chank shell beads from prehistoric site of Qulong in Ngari Prefecture, Tibet, China

“Applying red” is a common phenomenon observed in Chinese archaeological sites, with the red pigments having been identified as red ochre or cinnabar if ever been scientifically analyzed. However, this is not the case for Tibet. Although a relatively large number of red-painted artifacts have been recovered in Tibet dating from the Neolithic Period to the Tubo Dynasty, little effort has been made on the pigment composition. Recently, nearly one hundred red substances covered shell beads made of the scared chank (Turbinella pyrum), a large conch from the Indian Ocean, were unearthed from the Qulong site (c. 800–500 BC) in the Ngari plateau, western Tibet. This shell beads assemblage represents the largest and most concentrated group of chank shell beads recovered in the Tibetan Plateau and its surrounding regions. It provides a crucial clue for exploring the local “applying red” tradition. In this study, eight shell beads excavated from the Qulong site were examined by the Portable Energy-dispersive X-ray Fluorescence Spectrometer (pXRF), X-ray diffraction (XRD), Fourier Transform infra-red spectroscopy (FTIR), and Laser Raman spectroscopy. The results are as follows: 1) the coloring agent of all red pigments on the shell bead is iron oxide, i.e., red ocher; 2) bone powder that has not been heated to high temperatures (above 600°C) and proteinaceous binders were added to the paint on the outer surface of sample QSM1-11a, but the thin layer on its interior surface was without bone powder; 3) bone powder was not added to the red residues on samples other than QSM1-11a, QSM1-13b, and QSM2-12. This research may reveal the complexity and diversity of the red substances applied to shell beads from Qulong, and shed light on our understanding of human practices and local customs in the Tibetan plateau and the surrounding areas in prehistoric times.

Evaluating possible prehistoric cave art in the central Mediterranean: Analyses of pigment traces and identification of taphonomic processes at Għar Ħasan, Malta

The archaeology of the Maltese Islands, particularly the megalithic ‘temple’ structures and underground mass burial sites (hypogea) of the ‘Temple Period’ (ca. 3800 – 2300 BCE), has been the subject of considerable interest. Less is known about the prehistoric use of caves. In particular reports of prehistoric cave art at Għar Ħasan (Hasan’s Cave) have remained controversial, and have been argued to reflect an otherwise unknown pre-Neolithic occupation on the islands.Here, we report a reinvestigation of Għar Ħasan. To distinguish graffiti that have accumulated over the last century and possible older rock art, a range of non-invasive methods were used to determine the chemical properties and colour spectrum of the pigment traces: portable energy-dispersive X-ray fluorescence spectrometry (p-ED-XRF) and visible (VIS) and near-infrared (NIR) spectroscopy. In addition, pigment traces were analyzed with digital microscopy and image enhancement techniques (DStretch).Most of the previously reported cave paintings were shown to have been produced in the last century. One key panel may be older, but vandalism and other destructive processes make a definitive assessment challenging. While we therefore consider the evidence for ‘Palaeolithic’ cave art at Għar Ħasan to be inconclusive, our study also identified complex taphonomic processes that pose severe limitations on the identification of pigment via p-ED-XRF and spectroscopy and can inform and guide future initiatives for rock art conservation.

Rapid screening of pharmaceutical products for elemental impurities by a high-resolution portable energy dispersive X-ray fluorescence spectrometer using an efficient fundamental parameter method.

In this study, a rapid screening method for elemental impurities in pharmaceutical products has been established by portable energy dispersive X-ray fluorescence (EDXRF) spectroscopy combined with the efficient fundamental parameter method. The proposed method has been used for the screening of 22 elemental impurities (i.e., Cd, Pb, As, Hg, Co, V, Ni, Tl, Au, Pd, Ir, Os, Rh, Ru, Se, Ag, Pt, Sb, Mo, Cu, Sn, and Cr) in the International Conference on Harmonization (ICH) Q3D guideline. The verification of results could meet the acceptance criteria for accuracy, precision and linearity in the United States Pharmacopoeia 〈233〉. On the other hand, the limit of quantitation of the proposed EDXRF method for the screening of 22 elemental impurities in pharmaceutical products could meet the concentration limits of each element at 10 g maximum daily intake based on the established permitted daily exposure to oral drugs in the ICH Q3D guideline. Our findings open up new possibilities in the rapid screening of pharmaceutical products for the detection of elemental impurities by EDXRF, which can be expected to provide a novel, nondestructive, high-throughput, portable, and sensitive platform for the process control of elemental impurities to ensure the quality and safety of drugs.

Non-destructive characterisation of dolerite archaeological artefacts

A methodological proposal for the characterisation of dolerite rock aiming to test a non-destructive and non-invasive analytical approach has been developed. Geological samples were collected from several natural outcrops and studied together with seven archaeological stone tools found in a Chalcolithic site of the southern Valencian Community (Spain). The samples were analysed employing portable energy dispersive X-ray fluorescence spectroscopy, Raman microspectroscopy and Fourier transform near infrared spectroscopy. The obtained data were statistically processed in order to evaluate affinities and differences among the geological outcrops and to evaluate the possible provenance of the stone tools. The results of the different techniques were compared and evaluated. The three techniques showed results that were in most of the cases consistent one with each other, suggesting that combining multielement analysis and Raman could be a good way to identify stone tools raw material procurement, being the prior step for the reconstruction of ancient exchange networks.

Determining the sensitivity curve of Energy Dispersive X-ray Fluorescence and PIXE systems

The study of thin and thick materials every time is a challenge in X-ray analysis. The calculation of the sensitivity curve of Energy Dispersive X-ray Fluorescence (ED-XRF) and Particle Induced X-ray Emission (PIXE) systems allows for better quantitative analysis and also allows the determination of the concentration of a chemical element in a given thin sample from its intensity. The sensitivity curve can be found through the analysis of elemental standards, samples with well-defined superficial densities (μg/cm 2) that allow the calculation of the sensitivity of the system to the elements present in the standards. From these standard values, it is possible to fit a curve and find the sensitivity equation as a function of the atomic number. After that, the sensitivity curve which will be used to determine the elemental composition can help to calculate the concentration of any of the chemical elements of the periodic table present in a sample. Also, PIXE and ED-XRF are known to have a different sensibility and limits of detection (LOD) to determine elemental concentrations. In this article, the sensitivities of a portable ED-XRF and a PIXE system were calculated and compared. Altogether, the results showed that, for the experimental setups used, ED-XRF has better sensitivity associated with the chemical elements of intermediate atomic numbers, while PIXE’s functions describe better the sensitivities to the lighter and heavier chemical elements of the periodic table.

Archaeometallurgical Analysis of Lead Weights and Sling Bullets from Seleucid Tell Iẓṭabba: More on Lead Origin in Seleucid Palestine

Lead isotope and portable energy-dispersive X-ray fluorescence spectrometry were applied to a small group of Hellenistic lead objects from Tell Iztabba (Beth Shean, Israel). The market weights and sling bullets from this short-lived Seleucid-founded site were analysed in order to understand their production process and the provenance of the raw materials. The sling bullets are of pure lead, and its lead isotopic signature suggests that the lead was produced from Lavrion ores. The weights are heterogeneous in composition and point to the use of mixed or reused scrap metal. Anatolian or Aegaean lead ores are the raw material sources for the weights. Whether the sling bullets belonged to the defenders of the site or to the attackers cannot be determined from the analysis, but their Greek provenance together with the fact that they were recovered at the site may suggest their use by its defenders.