Portable X-ray Fluorescence Research Articles

Development of a portable battery-powered total reflection X-ray fluorescence spectrometer.

The detection of nuclear materials is crucial in cases of potential leaks or accidents; however, transporting samples out of such locations may be challenging, necessitating on-site analysis. While total reflection X-ray fluorescence (TXRF) analysis is a highly useful method for determining nuclides with long half-lives, such as uranium isotopes, no commercially available portable TXRF spectrometers can currently operate without an external power source, which may not always be accessible on-site. In this study, we modified the design of a commercially available portable TXRF spectrometer to develop a battery-powered device, enabling TXRF analysis outdoors and in locations without an external power supply. To test the applicability of the device, we analyzed the uranium content in a sample solution, using yttrium as an internal standard. The relative sensitivity coefficient was the same as that of the commercial spectrometer but the limit of detection was deteriorated. Addressing the equipment issues identified in this study is expected to enable efficient and rapid on-site TXRF analysis.

PXRF Skeletal Measurements as an Assessment Tool for Environmental Exposure to Lajes Field-Derived Contaminants (Terceira Island, Azores, Portugal).

Lajes Field is an Atlantic Portuguese military air base that has been used by the USA since the Cold War, primarily for intercontinental refueling. For this purpose, large fuel tanks and an extensive pipeline network were constructed within the municipality of Praia da Vitória, on Terceira Island, Azores. Over the past two decades, fuel leaks were detected and confirmed to have contaminated soils and the aquifers that supply water for public use. For the latter, identified contaminants include TPH, PAH, BTEX, VOCs, and metals. Although risk assessment reports have identified unacceptable risks to human health, and journalistic investigations suggest unusually high cancer rates, no assessment on possible human exposure has been conducted to date. To address this gap, metals, serving as a proxy for overall contamination exposure, were measured using portable X-ray fluorescence (pXRF) in the First Identified Skeletal Collection of the Azores (CEI/Açores). A total of 64 skeletons with known places of last residence were selected (44 from Angra do Heroísmo, where no exposure risk is present, and 20 from Praia da Vitória, where risk is present). No significant differences in mean ages at death were observed between the groups, and sex distribution was similar. Additionally, soil samples from 46 graves were analyzed to assess potential diagenesis. Greater concentrations of Sb, As, Cd, Cr, Au, Mo, Sr, Sn, U, and Zr were found in individuals from Praia da Vitória (p < 0.05). Soil measurements, Pearson's correlation test, and a principal component analysis suggest that the differences in Zr and As levels can be partially attributed to diagenesis. For the remaining metals, the observed differences likely result from other factors, including potential contamination exposure, particularly for Cd, Cr, and Mo. Although this pioneering study contributes to the ongoing discussion on the subject, further research should be conducted both in the CEI/Açores and the living population to further discuss this issue.

Diagnostic characterisation of masonry and decorative materials of the apsidal area of the Cathedral of Cefalù (Sicily, Italy)

The Cathedral of Cefalù (Sicily, Italy), a UNESCO World Heritage Site since 2015, was built during the Norman rule and is famous for its magnificent mosaic. The mosaic apparatus, located in the apsidal area of the Cathedral, recently underwent extensive conservation work. Besides the mosaic tesserae, this area of the Cathedral was subjected to interventions aimed at preserving the integrity of masonry plasters, mortars, stuccoes and coloured plasters. However, basic information such as the chemical and mineralogical composition and microstructural arrangement of original materials was still lacking. In this perspective, in situ and ex situ analyses were carried out for the first time on the masonry and decorative materials of Cefalù’s Cathedral apse. Chemical analyses were carried out on original mosaic tesserae by means of portable X-ray fluorescence, highlighting that their manufacture involved the recycling of glass, excluding the use of natural glass and identifying the chromophores responsible for the wide colour variety; X-ray diffractometry was performed on masonry plasters and mortars allowing to recognise the use of predominantly carbonatic binders and the presence of degradation products such as calcium oxalates and sodium chloride; finally, petrographic observations carried out on stuccoes enabled the identification of various types of aggregates (carbonatic, gypsum-based, and quartz-feldspathic) embedded in a carbonatic binder, while petrographic analysis of the coloured plasters allowed the identification of three pigmentation techniques. Overall, these analyses provided very useful information on the nature of building and decorative materials as well as their mineralogical composition and degradation products, laying the foundations for future conservation work that takes into account the characteristics of each material.Graphic abstract

Portable X-ray fluorescence (pXRF) application for plant nutrition analysis and environmental hazard evaluation in tropical environment

Understanding nutrient availability and pollution risk in plants is essential for effective environmental and agricultural management. This study evaluates the performance of portable X-ray fluorescence (pXRF) for nutrient analysis in tropical plant samples, comparing it to inductively coupled plasma optical emission spectroscopy (ICP-OES). We analyzed 24 composite samples of cocoa, oil palm, cocoyam, and maize leaves and barks from western Ghana, focusing on K, Ca, Mn, Fe, Cu, Zn, Sr, Cd, Mg, Al, P, S, Ti, Ni, and Co. Our findings revealed K as the most abundant nutrient, with ICP-OES emphasizing the importance of Ca, Mg, and various micronutrients. Trace elements like Sr and Cd were present at minimal, non-threatening levels. A paired t-test showed no significant differences between pXRF and ICP-OES for key elements such as Ca (−1.71654), Mn (1.12), Fe (1.32), Al (1.71), and Ni (0.735), with all t-values below the critical threshold (t_tab = 1.714), confirming pXRF’s effectiveness. Regression analysis indicated strong correlations for Al (r² = 0.8185) and P (r² = 0.7172), while weaker correlations were observed for Cd (r² = 0.0001).Principal component analysis revealed less variability in pXRF data compared to ICP-OES, reinforcing its reliability. ANOVA results showed that organ type significantly influenced elemental concentrations (F = 5.541, p = 0.0203), with K and Ca being the most abundant. Overall, pXRF is a cost-effective tool for nutrient monitoring, though further improvements in sensitivity for certain elements are recommended for broader applications.

Composition of late seventeenth century window glass from Scotland

SUMMARY Samples of glass from four sites in Scotland were analysed using portable X-ray fluorescence. Three of the sites were archaeological excavations in Ullapool, Stirling and Hume Castle, where glass shards were recovered; the fourth site was a historic building, Traquair House, with original window glass in situ. Each of the sites yielded a chemically distinct type of glass that is remarkably consistent across all four locations. Chemically, the glass recovered shares some characteristics with high lime low alkali (HLLA) glass, used throughout the seventeenth century, and some with kelp fluxed glass, used from the late seventeenth century to the 1840s. The glass appears to be a hybrid of both, representing a late seventeenth century transitional phase from one form of alkali flux to another. Possible sources of this glass type are discussed.

Rapid Detection of Available Cr(VI) in Soil Based on pXRF Combined with Ion-Exchange Resin

The detection of available Cr(VI) in soil is critical due to its high uptake by plants, which enables it to enter the food chain and pose significant health risks to humans. Traditional detection methods are often time-consuming and labor-intensive, limiting their suitability for rapid, on-site measurements. This study introduces a novel approach for the rapid detection of available Cr(VI) in soil, utilizing portable X-ray fluorescence spectrometry (pXRF) in combination with ion-exchange resin. The method was validated using soil samples from three distinct regions, representing three different soil types. Compared to conventional laboratory methods, the detection rates for Cr(VI) ranged from 80.73% to 124.14%, with relative standard deviations for repeated analyses ranging from 3.05% to 5.73%, both of which comply with national standards. Regression analysis confirms a strong linear relationship between spectral values and Cr(VI) concentration in standard solutions (R2 = 0.9986). Through resin enrichment, the detection limit (LoD) for Cr(VI) in soil solution reaches 0.070 mg/kg, facilitating trace-level detection of available Cr(VI) in soil. In contrast to traditional methods, the pXRF-ion-exchange resin approach minimizes secondary environmental contamination, is cost-effective and time-efficient, and does not require complex soil pretreatment. Consequently, it is highly suitable for rapid, on-site soil analysis. This study presents an innovative method for the detection of available Cr(VI) in soils. This approach effectively reduced analysis time and simplified sample pretreatment, and thus holds substantial potential for practical application.

Prospecting the first Chilean Martian simulants from the Atacama Desert for ISRU and potential applications

Prospecting the first Chilean Martian simulants from the Atacama Desert for ISRU and potential applications

Simultaneous quantification of light elements in food based on portable energy dispersive X-ray fluorescence (p-XRF) combined with second-order calibration algorithm

Simultaneous quantification of light elements in food based on portable energy dispersive X-ray fluorescence (p-XRF) combined with second-order calibration algorithm

Geometallurgical Characterization of the Arthur River Magnesite Deposit, Northwestern Tasmania for Pathways to Production

The Arthur River magnesite deposit is in the northwestern part of Tasmania, Australia, within the Arthur Metamorphic Complex. Physical, mineralogical, and chemical characteristics of the deposit were studied using geological drill core logging and analytical techniques (scanning electron microscopy, portable x-ray fluorescence, and laser ablation–inductively coupled plasma–mass spectrometry). The results document variations within the ore body, and three ore types have been identified for the potential production of an economic magnesite concentrate separated from associated gangue minerals (dolomite, quartz, and talc and iron bearing minerals such as pyrite and pyrrhotite). The ore types were identified based on a combination of physical, chemical, and mineralogical differences. Type 1 has a relatively high magnesium content and appears in drill core as hard white crystalline magnesite. Type 2 has relatively lower magnesium and higher iron contents than type 1 and occurs visibly as creamy-yellowish soft magnesite. Type 3 ore has the lowest magnesium and the highest iron content of the three ore types and is reddish brown in color. From the characterization studies, potential beneficiation routes for each ore type are suggested along with potential processing challenges. Examples of processing challenges include magnesium present in both magnesite and in dolomite, and the association of magnesite with quartz and talc results in a relatively high silica content.

A study on the possible construction order of the temples in Mahendraparvata on the summit of Kulen Mountain, Cambodia, based on brick and sandstone materials

The Angkor monument is a group of temples built between the 9th and 15th centuries. Mahendraparvata, the first capital of the Angkor Empire, was built by King Jayavarman II on the summit of Kulen Mountain, ~35 km northeast of Siem Reap, Cambodia. In this study, we investigated the building materials of the 18 temples that make up Mahendraparvata and found that mainly bricks were used in the construction of temples in Mahendraparvata. Gray sandstone, derived from the Phu Kradung Formation (the Red Terrain Formation) of the late Jurassic to early Cretaceous age (distributed in the southeastern foothills of Kulen Mountain and widely used throughout the Angkor monument), was used in small quantities at the door frames, stairs, and lintels of the temples. Chemical composition measured with a portable X-ray fluorescence analyzer and magnetic susceptibility measured with a portable magnetic susceptibility meter were conducted on the brick and sandstone materials, and the thickness of the bricks was also measured. On the basis of the magnetic susceptibility and Rb content of the bricks, the 18 investigated temples were categorized into three groups: Groups A, B, and C. The Rb content of the gray sandstone revealed that Group A differs from Groups B and C. Temples in Group A, namely Prasat O Phaong, Prasat Khmum, and Prasat Kraham (I & II), are aligned in a straight line, and Prasat O Phaong, Prasat Rong Chen, and Prasat O Top are also aligned in a straight line. The intersection of these two lines is at Prasat O Phaong. This suggests a possible relationship among the temples in Group A. Temples in Group A tend to be in better condition than those in other groups. The thickness of the bricks used in the temples of Mahendraparvata is between the thickness of bricks used in the Sambor Prei Kuk monument from the pre-Angkorian period and those of the temples of Hariharalaya, the next capital after Mahendraparvata. During these periods, there was an overall trend of decreasing brick thickness over time, suggesting a technical connection among these monuments.

Scientific investigation of the 20th century bronze bell in Asyut, Egypt: insight into materials, chemical composition and preservation status

This research presents an historical background and an analytical and study of a bell dating back to the 20th century, currently located at Al Salam Modern School, an ancient school, formerly known as the American College in Asyut, Egypt, which was established during the period between 1901 and 1909. The bell consists of metal parts (Bowl, Yoke, Standards, Clapper, Clevis Bolt, Toller, and Bearing) and wooden parts (Base or Frame and Wheel). These components were studied and analyzed using microscopic examination, Portable X-ray fluorescence (p-XRF) Scanning electron microscopy (SEM), coupled with an energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Visual and microscopic examination revealed the presence of corrosion products on the surface of the bell and its metal parts, bird droppings, embrittlement of the wood structure, fiber breakage, and accumulation of dust. The bell’s wooden parts were identified as oak using a light microscope. The body of the bell itself was analyzed using p-XRF and EDX, which revealed that the alloy used for its making is mainly composed of copper and tin, known as tin-bronze alloy. XRD analysis was used to identify the corrosion products on the surface of the bronze bell as well as the corrosion products of the parts made of iron. The results revealed that the corrosion products formed on the bell surface are Nantokite, Paratacamite, Atacamite, Brochantite, Antlerite, Cassiterite and Gypsum, while the rust products on the iron parts are Magnetite, Hematite, Goethite, Akaganeite, Lepidocrocite and Gypsum. FTIR analysis of the wooden parts of the bell showed the embrittlement and the decomposition of hemicellulose and lignin. This analysis also showed that the paints used in painting the wooden parts is a local paint known as ARTEX (Pachin).

Determining Gold Thickness in Multilayer Samples by Measuring the Intensity Ratio of the Au-Lα/Fe-Kα X-Ray

Multilayer samples are used in a wide range of sectors for their functionality. In the field of cultural heritage, multilayer samples are also common, as in the case of gilded or silvered alloys in the pigment layers in paintings. The X-ray ratios Lα/Lβ, Kα/Kβ, or K/L for an element or for different elements in a multilayer sample depend on the chemical composition and thickness of the superimposed layers and on the chemical composition and thickness of the layer in which the element is situated. Gold decorations of paintings on wood represent examples of multilayered structures and, for this reason, it is important to be able to determine the thickness of the gold layer. In the present paper, gold coatings of several paintings on gilded wood, by Italian artist Taddeo Gaddi (1300–1366 AD), were examined using portable energy-dispersive X-ray fluorescence (ED-XRF) in order to calculate the thickness of the gold layer on ochre by measuring the intensity ratio of the Au-Lα/Fe-Kα X-ray. The experimental results obtained showed that the gold leaves used by the artist have a thickness of approximately 0.3 to 0.4 µm; this also demonstrates the artist’s remarkable ability in creating the gilding.

Fast, in situ, and eco-friendly determination of Mn in plant leaves using portable X-ray fluorescence spectrometry for agricultural and environmental applications.

The portable X-ray fluorescence (pXRF) spectrometry has been very useful for the characterization of different earth materials, and its application for foliar analysis is really promising. The performance of pXRF for foliar analysis depends on several factors such as concentration of the elements, fluorescence yield which is influenced by atomic number, spectral interference, and water content. Mn is one of the elements that present a prominent fluorescence peak. In this sense, it was hypothesized that pXRF can directly determine the Mn concentration on foliar samples, even when used on intact leaves (fresh or dry) being a useful tool for agronomic and environmental purposes. Thus, the objective was to assess the performance of a pXRF to determine Mn concentration in two different foliar datasets from Brazil/South America and Mali/Africa. In the Brazilian dataset, leaves from eight crops (common bean, castor plant, coffee, eucalyptus, guava tree, maize, mango, and soybean) were scanned via pXRF at the following conditions: intact and fresh leaves, intact and dry leaves, and powdered samples). In the Malian dataset, powdered samples from cotton and maize were analyzed via pXRF. For comparison, Mn concentration was also determined after nitro-perchloric digestion followed by quantification via inductively coupled plasma optical emission spectroscopy (ICP-OES). After descriptive statistics, linear regressions were performed for all sample preparation conditions in both datasets, using Mn concentrations obtained through pXRF and the acid digestion method. The data quality level of all linear regressions was considered quantitative with high R (0.93 to 0.98) and R2 (0.87 to 0.96) values. The direct analysis of Mn via pXRF on intact and fresh leaves yielded R of 0.93, R2 of 0.87, and a low relative standard deviation (< 10%). The manufactured pXRF calibration used in this work allowed an accurate direct Mn determination in plant leaves. Considering the importance of Mn as a plant micronutrient and its potential toxicity depending on soil redox conditions, the fast, in situ, non-destructive, and eco-friendly determination via pXRF has a tremendous agronomic and environmental application worldwide.

Accessible Non-Invasive Techniques for Museums: Extending Sustainability to Resource-Limited Institutions

This work provides a synthesis of an initial experience in the development of accessible imaging techniques and their implementation on a real case: the analysis of colonial Hispano-American paintings at the Complejo Museográfico Provincial “Enrique Udaondo” (Luján, Buenos Aires). It discusses different aspects related to the possibilities of obtaining, using, and reusing equipment and materials locally, as well as details of the ways of acquiring images for photography on site. It also provides information about the composition and conservation state of selected artworks, complementing image analysis with portable X-ray fluorescence (XRF) data, and reflects on articulated/collaborative work in situ as a methodology for transferring knowledge and skills. The project aims to contribute to strengthening Latin American sustainability by creating accessible non-invasive tools for heritage conservation institutions, highlighting the value of regional capacities to approach heritage studies from collaborative and ethical proposals that promote sovereignty and reduce dependence on external inputs.

Direct, rapid, non-destructive and 'white' multielemental toxicological analysis of hazardous elements with health risk assessment in candies and wrappers from Polish flea markets using portable XRF spectroscopy.

Direct, rapid, non-destructive and 'white' multielemental toxicological analysis of hazardous elements with health risk assessment in candies and wrappers from Polish flea markets using portable XRF spectroscopy.

Measurement of hazardous elements as emerging contaminants from discarded Liquid Crystal Displays (LCDs) from mobile phones available in Poland using portable XRF as “white” analytical technique

Measurement of hazardous elements as emerging contaminants from discarded Liquid Crystal Displays (LCDs) from mobile phones available in Poland using portable XRF as “white” analytical technique

Metal exposures among Native Americans who inject methamphetamine.

Metal exposures among Native Americans who inject methamphetamine.

“Open Sourcing” Workflow and Machine Learning Approaches for Attributing Obsidian Artifacts to Their Volcanic Origins: A Feasibility Study from the South Caucasus

Traditionally, reliable obsidian sourcing requires expensive calibration standards and extensive geological reference collections as well as experience with statistical processing. In the South Caucasus — one of the most obsidian-rich regions on the planet — this combination of requirements has often restricted sourcing studies because few projects have geological reference collections that cover all known obsidian sources. To test an alternative approach, we conducted “open sourcing” using portable X-ray fluorescence (pXRF) analyses of geological specimens with three key changes to the conventional method: (1) commercially available calibration standards were replaced with a loanable Peabody-Yale Reference Obsidians (PYRO) set, (2) a comprehensive geological reference collection was replaced with a published dataset of consensus values (Frahm, 2023a, 2023b), and (3) processing in statistical packages was replaced with two semiautomated machine-learning workflows available online. For comparison, we used classification by-eye with JMP 17.2 statistical software. Furthermore, we propose a new method to evaluate calibrations, which streamlines comparisons and which we refer to as a symmetric difference ratio (SDR). The results of this feasibility study demonstrate that this “open sourcing” workflow is reliable, yet currently only in combination with classification by-eye. When the consensus values were combined with the machine-learning solutions, the classification results were unsatisfactory. The most encouraging aspect of our alternative “open sourcing” workflow is that it enables correct source identification without physically measuring reference collections, therefore surmounting an obstacle that, until now, has severely limited archaeological research. We anticipate that rapid developments in machine-learning will also soon improve the workflow.

Portable Analyses of Strategic Metal-Rich Minerals Using pXRF and pLIBS: Methodology and Database Development

Strategic metals are indispensable for meeting the needs of modern society. It is then necessary to reassess the potential of such metals in Europe. For the exploration of strategic metals, portable XRF (X-Ray Fluorescence) and LIBS (Laser Induced Breakdown Spectroscopy) are powerful techniques allowing their multi-elementary analysis. This paper presents a database providing more than 2000 pXRF data and more than 4000 pLIBS spectra acquired on minerals from the Mineralogy and Petrology Museum of National and Kapodistrian University of Athens (NKUA), selected based on their potential in bearing strategic metals. The combination of these two portable techniques, along with expanding dataset on strategic metal-rich minerals, provides valuable insights into strategic metal affinities and demonstrates the effectiveness of portable tools for exploring strategic raw materials. Indeed, such database allows to strengthen the knowledge on strategic metals by producing statistic and chemometric analyses (e.g., boxplot, PCA, PLS) on their distribution.

Ways to Measure Metals: From ICP-MS to XRF.

This review explores the use of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-ray Fluorescence (XRF) for quantifying metals and metalloids in biological matrices such as hair, nails, blood, bone, and tissue. It provides a comprehensive overview of these methodologies, detailing their technological limitations, application scopes, and practical considerations for selection in both laboratory and field settings. By examining traditional and novel aspects of each method, this review aims to guide researchers and clinical practitioners in choosing the most suitable analytical tool based on their specific needs for sensitivity, precision, speed, and sample preparation. Recent studies highlight enhanced capabilities of both ICP-MS and XRF technologies, making them more adaptable to various analytical needs. ICP-MS is renowned for its unmatched sensitivity and precision in detecting ultra-trace metals and metalloids in complex biological samples, such as lead in plasma or seawater. XRF advancements include lower detection limits and reduced sample preparation time, enabling rapid, non-destructive analyses, ideal for quick field assessments. Portable XRF analyzers have revolutionized on-the-spot testing, providing robust data without traditional wet-lab constraints. Moreover, hybrid techniques combining ICP-MS and XRF features are emerging, offering rapid and precise metal analysis for environmental monitoring, clinical diagnostics, and epidemiological studies. Matching analytical methods to specific research demands is critical. ICP-MS is the gold standard for detailed quantitative analysis in laboratories, while XRF excels in non-destructive, immediate field applications. Selection should consider sample complexity, sensitivity, speed, and cost-efficiency. Integrating ICP-MS and XRF offers a versatile approach to metals analysis, transforming practices in environmental science and healthcare diagnostics. As these technologies evolve, they are promising to expand capabilities in detecting and understanding the roles of metals and metalloids in health and the environment.