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Synchrotron-induced X-ray fluorescence (Sy-XRF) analysis was used to study the chemical composition of precious Renaissance silverpoint drawings. Drawings by famous artists such as Albrecht Dürer (14711528) and Jan van Eyck (approximately 13951441) must be investigated non-destructively. Moreover, extremely sensitive synchrotron- or accelerator-based techniques are needed since only small quantities of silver are deposited on the paper. New criteria for attributing these works to a particular artist could be established based on the analysis of the chemical composition of the metal points used. We illustrate how analysis can give new art historical information by means of two case studies. Two particular drawings, one of Albrecht Dürer, showing a profile portrait of his closest friend, Willibald Pirckheimer (1503), and a second one attributed to Jan van Eyck, showing a Portrait of an elderly man, often named Niccolò Albergati, are the object of intense art historical controversy. Both drawings show inscriptions next to the figures. Analyses by Sy-XRF could reveal the same kind of silverpoint for the Pirckheimer portrait and its mysterious Greek inscription, contrary to the drawing by Van Eyck where at least three different metal points were applied. Two different types of silver marks were found in this portrait. Silver containing gold marks were detected in the inscriptions and over-subscriptions. This is the first evidence of the use of gold points for metal point drawings in the Middle Ages.
Spatially resolved X-ray fluorescence analysis using synchrotron radiation (SR-XRF) at the wavelength shifter beamline, BAMline, at BESSY was used to investigate Renaissance silverpoint drawings as it is extremely sensitive, non-destructive and can be carried out in air using an excitation spot in the hundred micrometer range.
This paper deals with first results of the study of silverpoint drawings of Albrecht Dürer (14711528) belonging to the sketchbook that Albrecht Dürer used during a travel to the Netherlands in 1520/21. These results are compared to a PIXE study performed on drawings from the same sketchbook.
The minor element composition of the silverpoint used for the drawings in the sketchbook was (10.6 ± 3.5) wt.% of Cu and traces of Zn. Mercury was found in the marks but does not belong to the initial composition of the silverpoint as it is attributed to an alteration phenomenon. One drawing of the sketchbook represents an exception. It consists of silver marks containing an additional minor element, Zn, in the marks and was, therefore, created with another silverpoint, probably at a different time than the other drawings.
A core component of energy storage systems like vanadium redox flow batteries (VRFB) is the polymer electrolyte membrane (PEM). In this work, the frequently used perfluorosulfonic-acid (PFSA) membrane Nafion™ 117 and a novel poly (vinylidene difluoride) (PVDF)-based Membrane are investigated. A well-known problem in VRFBs is the vanadium permeation through the membrane. The consequence of this so-called vanadium crossover is a severe loss of capacity. For a
better understanding of vanadium transport in membranes, the uptake of vanadium ions from electrolytes containing Vdimer(IV–V) and for comparison also V(II), V(III), V(IV), and V(V) by both membranes was studied. UV/VIS spectroscopy, X-ray absorption near edge structure spectroscopy (XANES), total reflection X-ray fluorescence spectroscopy (TXRF), inductively coupled plasma optical emission spectrometry (ICP-OES), and micro X-ray fluorescence spectroscopy (microXRF) were used to determine the vanadium concentrations and the species inside the membrane. The results strongly support that Vdimer(IV–V), a dimer formed from V(IV) and V(V), enters the nanoscopic water-body of Nafion™ 117 as such. This is interesting, because as of now, only the individual ions V(IV) and V(V) were considered to be transported through the membrane. Additionally, it was found that the Vdimer(IV–V) dimer partly dissociates to the individual ions in the novel PVDF-based membrane.
The Vdimer(IV–V) dimer concentration in Nafion™ was determined and compared to those of the other species. After three days of equilibration time, the concentration of the dimer is the lowest compared to the monomeric vanadium species. The concentration of vanadium in terms of the relative uptake λ = n(V)/n(SO3
) are as follows: V(II) [λ = 0.155] > V(III) [λ = 0.137] > V(IV) [λ = 0.124] > V(V) [λ = 0.053] > Vdimer(IV–V) [λ = 0.039]. The results show that the Vdimer(IV–V) dimer Needs to be considered in addition to the other monomeric species to properly describe the transport of vanadium through Nafion™ in VRFBs.
Fourteen hollow and one cast anthropomorphic and zoomorphic figurines produced in Incan times for ritual offerings from the Ethnologisches Museum in Berlin were selected to investigate the technologies and alloys used for their fabrication with portable optical microscopy and non-destructive XRF elemental analysis. This group of gold and silver figurines includes typical specimens of the Inca production, such as the four silver figurines from the Island Coati in Lake Titicaca and the two gold figurines from Pachacamac, as well as specimens that are seldom present in collections, which makes them atypical. In addition to the tall figurines with atypical hair or standing pose, one bicolour figurine half silver, half gold) and another with coloured inlays were included in this study for comparison. The large majority of the silver specimens are made from very high quality alloys and the gold figurines are made from alloys containing low copper contents and silver ranging from 30wt% to 52wt%.
Die naturwissenschaftliche Analyse historischer Materialen ermöglicht die Beantwortung kulturhistorischer Fragestellungen, die mit kunsthistorischen oder archäologischen Ansätzen allein nicht zu leisten sind. In dieser Studie wurden sechs römische Münzen mit unterschiedlich stark ausgeprägten Korrosionsschichten an unbehandelten und polierten Stellen mit vier zerstörungsfreien analytischen Methoden untersucht: Hoch- und Niederenergie Protonen Induzierter Röntgenemission (HE-/PIXE), Synchrotronstrahlungsinduzierte-Röntgenfluoreszenzanalyse (SY-RFA) und Mikro-Röntgenfluoreszenzanalyse (Mikro-RFA) mit einem mobilen Gerät. Aufgrund von Unterschieden in den Messbedingungen und dem Einfluss der Patina-Schichten auf diese ergaben sich nur für wenige Elemente Übereinstimmungen in den quantitativen Daten. Zur Validierung zukünftiger Messkampagnen mit verschiedenen Methoden sind daher Vergleichstudien unerlässlich.
Increasing numbers of implant revisions are a current clinical issue. Interactions of the endoprosthesis biomaterial with the body affect implantation time by wear processes, i.e. corrosion and abrasion. Previously, cobalt-chrome implants were shown to cause high levels of cobalt ions being deposited in the bone matrix. To determine a poten- tial functional role of these ions on bone homeostasis, we have developed a non-destructive dual analysis of highly sensitive elemental analysis by synchrotron XRF directly in undecalcified histological bone thin sections (4 μm). In this study, samples from 28 bone samples from hip endoprosthesis carriers (Surface Replacement Arthroplasty, metal-on-metal bearing) with an implant lifetime of 17–1750 days were used. Results were compared to age- matched control specimens. The histological analysis identified areas of bone cell activity and assigned them for XRF measurements. Co-Cr wear particles were identified in the bone marrow. In addition, Co ions were highly enriched in the mineralized bone matrix. The cobalt deposits were not homogeneously distributed, and areas of high signal intensity were identified. Co was distinctly deposited in the newly formed osteoid layer, but also within deeper layers of the bone matrix, whereby the Co concentration increased with higher degrees of bone matrix mineralization. In the current study, we determined cobalt accumulations in the bone matrix and showed for the first time via synchrotron XRF with a high spatial resolution direct on histological slides, that cobalt deposits in the mineralized bone matrix in a mineral-specific way that is dependent upon the implant lifetime.
Chemical state of chromium, sulfur, and iron in sewage sludge ash based phosphorus fertilizers
(2015)
As an essential element of all life forms, phosphorus (P) is vital to the fertilizer industry. With decreasing quantity and quality of phosphate rock resources, recycling P-fertilizers from wastewater is of increasing interest. The P-fertilizer products of a recently developed thermochemical process for P recovery from sewage sludge ash (SSA) were investigated by chromium, sulfur, and iron K-edge X-ray near-edge structure (XANES) spectroscopy. This paper focuses the formation and prevention of toxic chromium(VI) and toxic sulfides during the thermochemical processes. Reducing conditions prevent the oxidation of chromium(III) in the SSA to toxic chromium(VI). Sulfides formed under the reducing conditions are nontoxic iron sulfides. Hematite (Fe2O3) present in the SSA is reduced to magnetite (Fe3O4). A gentle post-treatment at 400 °C under oxidizing conditions converts the iron sulfides into plant-available iron sulfates. This oxidative post-treatment does not form undesired chromium(VI) compounds.
A new concept that comprises both time- and lateral-resolved X-ray absorption fine-structure information simultaneously in a single shot is presented. This uncomplicated set-up was tested at the BAMline at BESSY-II (Berlin, Germany). The primary broadband beam was generated by a double multilayer monochromator. The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by either an energy-sensitive area detector, the so-called color X-ray camera, or by an area-sensitive detector based on a CCD camera, in θ-2θ geometry. The first tests were performed with thin metal foils and some iron oxide mixtures. A time resolution of lower than 1 s together with a spatial resolution in one dimension of at least 50 µm is achieved.
With the aim of improving limits of detection (LOD) of trace elements in a matrix with adjacent fluorescence energies, a simple double dispersive X-ray fluorescence detection system (D2XRF) was constructed to operate at the beamlines BAMline and the mySpot @ BESSY II. This system is based on the combination of a crystal analyzer with an energy resolving single photon counting pnCCD. Without further collimators, the efficient suppression of the background by the pnCCD and the good energy resolution of the crystal results in improved LOD. In first order reflections, an energy resolution of 13 eV for Cu Kα was reached, and an energy range of 1 keV was covered in one shot.
This new system was applied to the detection of platinum (Pt) in gold leaves with a LOD of 0.9 mg/kg, which is the lowest attained by totally non-destructive methods nowadays. The presence of Pt in gilded objects from Abydos and Byzantine mosaics provides vital information, as it indicates the alluvial origin of the gold for these examples.
Partial least squares (PLS) regression-based methods have been proven to be a good alternative for quantification in X-ray fluorescence spectroscopy. These methods are fast and easy to use though giving satisfactory results under certain conditions. One of these conditions is the necessity of having a great number of spectra to build the model (training set). The choice of the constituent concentration range in the training set has a big influence on the accuracy of the model. Better accuracy is obtained if the model is built in relatively narrow regions containing (or close to) the real concentration value.
In the present work, Monte Carlo (MC) simulated spectra are used to form the training set. The advantage to use MC generated training spectra is the unlimited availability of perfect standards.
This paper aims to improve the accuracy of the method by introducing a multiple step procedure in order to build the PLS model using narrow concentration range close to (or containing) the real concentration values in the samples to be measured.
This approach consists of an initial guess of the constituents' concentrations and a preliminary PLS model before building the final model. The prediction of ten MC simulated alloy standard samples containing Ti, Mn, Fe, Co, Cu, Zn, Sr, Zr, and Mo using this method allowed to have average relative prediction errors less than 5% for elements with narrow concentration ranges.
Evaluation of total reflection X-ray fluorescence (TXRF) analysis using a color X-ray camera (CXC)
(2013)
Adaptive Kanalreduktion eines hyperspektralen Bilddatensatzes kombiniert mit k-mean Clustering
(2014)
Slicing - A New Method For Non Destructive 3D Elemental Sensitive Characterization Of Materials
(2013)
Slicing - A New Method For Non Destructive 3D Elemental Sensitive Characterization Of Materials
(2014)
News from the BAMline
(2017)
Gold ist eines der sieben schon im Altertum bekannten Metalle und wurde wg. seines Glanzes und seiner Seltenheit von alters her als Tauschmittel und zur Herstellung von Schmuck benutzt. Außerdem ist es einfach bearbeitbar und weitestgehend gegen chemische Einflüsse resistent. Die Untersuchungen von Gold mit synchrotronstrahlungsangeregter Röntgenfluoreszenzanalyse sind zerstörungsfrei und geben Auskunft über die in der untersuchten Probe vorhandenen chemischen Elemente. Bei den hier vorgestellten Untersuchungen an der BAMline stehen Fragestellungen wie Herkunft, Herstellungsverfahren und Zusammengehörigkeit von Goldfunden im Vordergrund. Die verschiedenen Fragestellungen werden an einer Reihe von Beispielen erläutert die vom Wikingerschatz aus Hiddensee über die Himmelsscheibe von Nebra bis hin zu Funden aus Ägypten langen. Zusätzlich werden die modernen Messmethoden vorgestellt, die am Synchrotron heutzutage zur Verfügung stehen.
Die Eigenschaften und die Verlässlichkeit von Materialien jeglicher Art sind seit jeher die Grundlagen der Technik einer Gesellschaft. Tiefgreifende Kenntnisse über sie sind deshalb eine Voraussetzung um neue Produkte zu entwickeln, Verlässlichkeit zu gewährleisten, oder aber auch, wie in der Archäometrie, Kenntnisse über die Vergangenheit zu gewinnen. Ein Schlüssel zum Verständnis ist das Wissen über die chemische Zusammensetzung und die Struktur von Materialien Die Analyse mit Synchrotronstrahlung bietet hierfür herausragende Werkzeuge an, die zerstörungsfrei und hochsensitiv sind. Mit Röntgenfluoreszenzanalyse kann die elementare Zusammensetzung in winzigen Proben bis auf μg/g bestimmt werden. Anwendungsbeispiele aus verschiedenen Themengebieten, aber besonders von archäologischen Fragestellungen wie z.B. dem Goldfund von Bernstorf werden im Vortrag vorgestellt.
Gold ist eines der sieben schon im Altertum bekannten Metalle und wurde wg. seines Glanzes und seiner Seltenheit von alters her als Tauschmittel und zur Herstellung von Schmuck benutzt. Außerdem ist es einfach bearbeitbar und weitestgehend gegen chemische Einflüsse resistent.
Die Untersuchungen von Gold mit synchrotronstrahlungsangeregter Röntgenfluoreszenzanalyse sind zerstörungsfrei und geben Auskunft über die in der untersuchten Probe vorhandenen chemischen Elemente.
Bei den hier vorgestellten Untersuchungen an der BAMline stehen Fragestellungen wie Herkunft, Herstellungsverfahren und Zusammengehörigkeit von Goldfunden im Vordergrund. Die verschiedenen Fragestellungen werden an einer Reihe von Beispielen erläutert die vom Wikingerschatz aus Hiddensee über die Himmelsscheibe von Nebra bis hin zu Funden aus Ägypten langen. Zusätzlich werden die modernen Messmethoden vorgestellt, die am Synchrotron heutzutage zur Verfügung stehen.
The gold finds from Bernstorf, in the Freising district of Bavaria, were discovered in 1998, in the area of a Bronze Age settlement. First analyses with X-ray fluorescence (XRF) revealed gold of an unusually high purity grade, which was explained by the use of cementation techniques. A newer analysis with laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) indicated an even higher purity. The analytical results were the starting point of an ongoing discussion. In this study, we re-analysed 11 gold samples with Synchrotron radiation–induced X-ray fluorescence at the BAMline at BESSY. In a thorough analysis, different excitation and detection conditions were applied to confirm or disprove the previous results. It was shown that the purity of the gold from the specimen is higher than 99.9%. The main impurities are silver in a range between 20 and 200 μg/g and copper between 1 and 10 μg/g. The results are in very good agreement with the LA–ICP–MS measurements and provide basic information for discussions about provenance, processing techniques or considerations of authenticity.
The Color X-ray Camera CXC or SLcam® is an energy-resolving X-ray camera capable of energy- and space-resolved measurements. It consists of a high-speed CCD detector coupled to a polycapil-lary optic that conducts the X-ray photons from the probe to distinct pixels onto the detector.
The camera is capable of fast acquisition of spatially and energy resolved fluorescence images. A dedicated software enables the acquisition and the online processing of the spectral data for all 69696 pixels, leading to a real-time visualization of the elements distribution in a sample. It was developed in a joint project with BAM, IFG Berlin and PN Sensors.
In this contribution we will mainly discuss the use of the CXC at our beamline, the BAMline at BESSY II and imaging applications of the CXC from different areas, like biology and archaeometry. Additionally new developments for the use of the detector without optics, like wavelength dispersive detection or 1shot-XANES, will be presented.
A major source of capacity fade of the common vanadium redox flow battery (VRFB) is the vanadium ion transport through the separator. However, different transport models disagree significantly in the diffusion coefficient for the different V species and the influence of different transport mechanisms. The underlying hypothesis of this work is that reactions inside the membrane are partly responsible for these discrepancies. Accordingly, it was investigated if redox reactions inside the nanoscopic water body of Nafion 117 can occur. X-ray absorption near edge structure spectroscopy (XANES) was used to distinguish between the different V species inside hydrated Nafion 117 and novel PVDF-based membranes. It was validated that the speciation of vanadium can be performed using the pre-edge peak energy and intensity. The experiments were performed as follows: strips of the membrane were exposed from one site to a V3+ solution (green) and from the other site to a VO2+ solution (yellow). The ions could diffuse into the membrane from both sides. A change of color of the membrane strip was observed. The blue color in the middle of the strip indicated that VO2+ was formed where V3+ and VO2+ got in contact. Using XANES this reaction inside Nafion was proven.
Sixteen Ayyubid-Mamluk glazed pottery sherds were analyzed in order to identify and characterize the elemental composition to determine their provenance. The tested sherds were collected from the historical site of Karak Castle, southern Jordan.
Chemical analysis for the sixteen samples has been carried out using Synchrotron Radiation X-ray Fluorescence Spectrometry (SR-XRF) Technique. Furthermore, the semiquantitative analysis of the elements Fe – Cu – Zn – Br – Rb – Sr – Y – Zr – Nb – Mo – Pd – Ag – Cd and Pb has been performed for the samples based on Principal Component Analysis (PCA) and hierarchical Cluster Analysis with Bray-Curtis in order to define grouping of different glazed pottery by obtaining information on their similarity and clustering. The results of chemical analysis provided persuasive evidence that the Karak Castle pottery sherds have at least three different sources of provenance.
Examples of XRF and PIXE imaging with few microns resolution using SLcam® a color X-ray camera
(2015)
We present results of recent development of the color X-ray camera, type SLcam®, allowing detection of X-ray images with few microns resolution. Such spectral resolution is achieved with the use of high-quality polycapillary optics combined with sub-pixel resolution. Imaging of Siemens star resolution test chart reveals that the resolution limit of SLcam® can go down to nearly 5µm. Several real sample examples of measurements carried out at the laboratory, synchrotron, and particle-induced X-ray emission beamlines are shown. This is the first time SLcam® is used as particle-induced X-ray emission detector.
Several glazed ceramic fragments (XVIth to XVIIIth centuries) from two production centers in Portugal (Coimbra and Lisbon) were the object of this study. The ones from Coimbra comprise two sets of samples: faiences and tiles. The ones from Lisbon are only tiles (azulejos, in Portuguese). The three main divisions of such pieces are the ceramic support (body), glaze and surface decoration. The system decoration/glaze is not easy to investigate, due to the high heterogeneity resulting from the mixing procedures and firing temperatures used. Moreover, the ability of the pigment to diffuse into the base glaze varies depending on the composition of both the pigment and the glaze in terms of fusibility. In order to raster these effects, high resolution techniques are required. In this work, synchrotron micro-X-ray fluorescence (µ-XRF) analysis was performed to monitor the profiles of the characteristic elements from the colors used and the glaze in well prepared cross-sections of the samples. Key elements are: Co for blue, Mn for purple, Cu for green, Sb for yellow, Pb for the glaze and Fe for the body. The major difference observed is that faiences have glaze thicknesses between 150 and 200 µm and tiles have glaze thicknesses between 350 and 400 µm. Furthermore, in faiences all the pigments except the yellow ones are well dispersed into the glassy matrix, while in tiles, all of them are just partially diffused throughout the glaze. However, differences between the tiles from Coimbra and Lisbon were observed. In the samples from Lisbon, a higher intake from the pigment throughout the glaze is observed.
Gold ist eines der sieben schon im Altertum bekannten Metalle und wurde wg. seines Glanzes und seiner Seltenheit von alters her als Tauschmittel und zur Herstellung von Schmuck benutzt. Außerdem ist es einfach bearbeitbar und weitestgehend gegen chemische Einflüsse resistent.
Die Untersuchungen von Gold mit synchrotronstrahlungsangeregter Röntgenfluoreszenzanalyse sind zerstörungsfrei und geben Auskunft über die in der untersuchten Probe vorhandenen chemischen Elemente.
Bei den hier vorgestellten Untersuchungen an der BAMline stehen Fragestellungen wie Herkunft, Herstellungsverfahren und Zusammengehörigkeit von Goldfunden im Vordergrund. Die verschiedenen Fragestellungen werden an einer Reihe von Beispielen erläutert die vom Wikingerschatz aus Hiddensee über die Himmelsscheibe von Nebra bis hin zu Funden aus Ägypten langen. Zusätzlich werden die modernen Messmethoden vorgestellt, die am Synchrotron heutzutage zur Verfügung stehen.
The BAMline at the synchrotron BESSY II in Berlin supplies users with up to date analytical x-ray methods for the energy range between 5 and 50 keV. Additional to XRF with micron Resolution it provides amongst other things the possibility to use TXRF and XANES. Especially the use of
the so-called Color X-Ray Camera (CXC) opens the possibility to use new and effective detection schemes, which allow to measure simultaneously distributions of elements or Absorption spectra in a motionless mode.
In this talk the analytical possibilities at the BAMline for samples with biological Background will be introduced. The available methods will be presented and discussed for various examples.
A perspective for the future use for XANES in grazing emission and TXRF geometries for plant materials will be given.
Gold mosaics, made from gold and glass, are one of the best expressions of Late Antique Byzantine and Early Islamic art. The gold alloys, whose composition seems to indicate that gold coins were re-used to fabricate the tesserae, can be used to provide information on the mosaics chronology. Monetary Byzantine gold is in fact characterized by the presence of Pt, which contents in the gold alloy change over time, but Pt must be measured in 0.2-0.4 µm thickness gold leaves that were beaten to be sandwiched between two glass layers.
To analyze this samples the D²XRF set-up at the BAMline at the BESSY synchrotron in Berlin was used. The combination of a crystal for wavelength dispersion and an energy resolving single photon counting pnCCD allows the realization of this very simple wavelength dispersive detection system. With this system an MDL of 1 μg/g for the determination of Pt in Au under optimal conditions can be reached.
Gold leaf tesserae from nine archaeological sites, covering the period that goes from the 5th c. to the 8th c., were analyzed. The presence of Pt in the majority of the samples confirmed the re-use of coins. The Pt contents separate the samples in three groups, one of which having the same chemical characteristics as the Byzantine gold could be compared to dated coins for chronology. The higher Pt contents for one of other groups suggest
Fire-gilding or amalgam gilding is a historical technique for the gilding of objects. The object to be gilded is coated with an amalgam (a solution of gold (Au) in mercury (Hg)). By heating, the largest part of the Hg is subsequently evaporated and there remains a gold layer, containing still detectable amounts of Hg.
The information on the used gilding technique might be crucial for the conservation and preservation of archaeological objects. Therefore, the main objective of this work is the detailed understanding of the behaviour of Hg under conditions of fire gilding. I.e. the understanding of the diffusion and evaporating behaviour of Hg, depending on parameters like substrate material (silver, copper, bronze, brass...), heating temperature and duration, and the resulting Hg depth profiles under these conditions. Secondary objective is the establishment of a measurement protocol for the unambiguous identification of different types of gilding, based solely on non-destructive methods, which can be applied to historical samples.
In a first step, fire-gilded samples have been prepared on Cu and Ag sheet metal, respectively. Some of the gildings were produced by a professional goldsmith; another set of samples was produced under laboratory conditions. These samples have been examined with NAA (neutron activation analysis) and SR-XRF (synchrotron radiation induced X-ray fluorescence). First results of these measurements will be presented and discussed.
The newly developed EXAFS set-up comprises both time- and spatially-resolved EXAFS information simultaneously in a single-shot. This facile, stable and scanningless set-up was tested at the BAMline @ BESSY-II (Berlin, Germany). The primary broadband beam is generated by a filter/X-ray-mirror combination (bandpass). The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by an area sensitive detector based on a CCD camera, in a theta - 2 theta geometry.
The first in situ measurements were successfully carried out and hereby presented. The case-study involved a well known reaction, in which structural changes are induced over time, and continuously measured. We were able to track structural changes within a 1s time resolution.
With the increase in the awareness of the public in the environmental impact of oil shale utilization, it is of interest to reveal the mobility of potentially toxic trace elements in spent oil shale. Therefore, the Cr and As oxidation state in a representative Jordanian oil shale sample from the El-Lajjoun area were investigated upon different lab-scale furnace treatments. The anaerobic pyrolysis was performed in a retort flushed by nitrogen gas at temperatures in between 600 and 800 °C (pyrolytic oil shale, POS). The aerobic combustion was simply performed in porcelain cups heated in a muffle furnace for 4 h at temperatures in between 700 and 1000 °C (burned oil shale, BOS). The high loss-on-ignition in the BOS samples of up to 370 g kg–1 results from both calcium carbonate and organic carbon degradation. The LOI leads to enrichment in the Cr concentrations from 480 mg kg–1 in the original oil shale up to 675 mg kg–1 in the ≥850 °C BOS samples. Arsenic concentrations were not much elevated beyond that in the average shale standard (13 mg kg–1). Synchrotron-based X-ray absorption near-edge structure (XANES) analysis revealed that within the original oil shale the oxidation states of Cr and As were lower than after its aerobic combustion. Cr(VI) increased from 0% in the untreated or pyrolyzed oil shale up to 60% in the BOS ash combusted at 850 °C, while As(V) increased from 64% in the original oil shale up to 100% in the BOS ash at 700 °C. No Cr was released from original oil shale and POS products by the European compliance leaching test CEN/TC 292 EN 12457-1 (1:2 solid/water ratio, 24 h shaking), whereas leachates from BOS samples showed Cr release in the order of one mmol L–1. The leachable Cr content is dominated by chromate as revealed by catalytic adsorptive stripping voltammetry (CAdSV) which could cause harmful contamination of surface and groundwater in the semiarid environment of Jordan.