TY - JOUR A1 - Ordavo, I. A1 - Ihle, S. A1 - Arkadiev, V. A1 - Scharf, Oliver A1 - Soltau, H. A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, S. A1 - Buzanich, Günter A1 - Gubzhokov, R. A1 - Günther, A. A1 - Hartmann, R. A1 - Holl, P. A1 - Kimmel, N. A1 - Kühbacher, M. A1 - Lang, M. A1 - Langhoff, N. A1 - Liebel, A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Schaller, G. A1 - Schopper, F. A1 - Strüder, L. A1 - Thamm, C. A1 - Wedell, R. T1 - A new pnCCD-based color X-ray camera for fast spatial and energy-resolved measurements JF - Nuclear instruments and methods in physics research A N2 - We present a new high resolution X-ray imager based on a pnCCD detector and a polycapillary optics. The properties of the pnCCD like high quantum efficiency, high energy resolution and radiation hardness are maintained, while color corrected polycapillary lenses are used to direct the fluorescence photons from every spot on a sample to a corresponding pixel on the detector. The camera is sensitive to photons from 3 to 40 keV with still 30% quantum efficiency at 20 keV. The pnCCD is operated in split frame mode allowing a high frame rate of 400 Hz with an energy resolution of 152 eV for Mn Kα (5.9 keV) at 450 kcps. In single-photon counting mode (SPC), the time, energy and position of every fluorescence photon is recorded for every frame. A dedicated software enables the visualization of the elements distribution in real time without the need of post-processing the data. A description of the key components including detector, X-ray optics and camera is given. First experiments show the capability of the camera to perform fast full-field X-Ray Fluorescence (FF-XRF) for element analysis. The imaging performance with a magnifying optics (3×) has also been successfully tested. KW - X-ray CCD camera KW - pnCCD KW - Fast X-ray imaging KW - XRF KW - Full-field X-ray fluorescence KW - Elemental analysis KW - High quantum efficiency KW - High energy resolution KW - Polycapillary optics PY - 2011 DO - https://doi.org/10.1016/j.nima.2011.05.080 SN - 0168-9002 SN - 0167-5087 VL - 654 SP - 250 EP - 257 PB - North-Holland CY - Amsterdam AN - OPUS4-24370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El-Hasan, T. A1 - Szczerba, Wojciech A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Kersten, M. T1 - Cr(VI)/Cr(III) and As(V)/As(III) ratio assessments in Jordanian spent oil shale produced by aerobic combustion and anaerobic pyrolysis JF - Environmental science & technology N2 - 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. KW - Trace-elements KW - Fly-ash KW - Speciation KW - Chromium KW - Sediments KW - Behavior KW - Metals KW - Xanes KW - Cr KW - Transformation PY - 2011 DO - https://doi.org/10.1021/es200695e SN - 0013-936X SN - 1520-5851 VL - 45 IS - 22 SP - 9799 EP - 9805 PB - ACS Publ. CY - Washington, DC AN - OPUS4-25290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grunewald, Christian A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Buzanich, Günter A1 - Riesemeier, Heinrich T1 - SRXRF-measurements at non-planar objects: automatic determination of the angle of incidence of the exciting X-ray JF - Journal of analytical atomic spectrometry N2 - For quantitative SRXRF measurements the angle of incidence of the incoming X-ray beam is an important factor. When the sample is focused by a long-range-microscope, the determination of the angle can be automatized using a simple algorithm. This was developed to improve the orientation of especially round or ornate samples. As a side effect the three dimensional surface can be reconstructed, too. KW - X-ray fluorescence KW - Synchrotron radiation KW - Long-range microscope PY - 2011 DO - https://doi.org/10.1039/c0ja00237b SN - 0267-9477 SN - 1364-5544 VL - 26 IS - 5 SP - 1088 EP - 1089 PB - Royal Society of Chemistry CY - London AN - OPUS4-23193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guilherme, A. A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Coroado, J. A1 - Dos Santos, J.M.F. A1 - Carvalho, M.L. T1 - Synchrotron micro-XRF with compound refractive lenses (CRLs) for tracing key elements on Portuguese glazed ceramics JF - Journal of analytical atomic spectrometry N2 - 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. KW - Synchrotron micro-XRF KW - Compound refractive lenses (CRLs) KW - Portuguese glazed ceramics PY - 2012 DO - https://doi.org/10.1039/c2ja30030c SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 6 SP - 966 EP - 974 PB - Royal Society of Chemistry CY - London AN - OPUS4-26789 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Streli, C. T1 - Micro-X-ray absorption spectroscopy with compound refractive lenses JF - Journal of analytical atomic spectrometry N2 - A study regarding the possibility to use compound refractive lenses (CRLs) for X-ray absorption spectroscopy (XAS) was conducted. For XAS measurements the energy of the monochromatic incident beam has to be tuned over an energy range which is broader than the energy bandwidth of a CRL. To prove that µ-XAS with compound refractive lenses is possible, it had to be investigated how changes in the energy influence the beam parameters. This was done by tuning the energy around the nominal energy of the lens and recording images with a high resolution X-ray imaging setup. To investigate the changes in the spot size the scintillator was placed at the nominal focal distance and scans along the beam axis were performed. The effect on the photon flux of the incident beam due to absorption in the lens was investigated by performing XANES measurement on different reference materials with and without CRL. The results of these measurements using a CRL designed for 9 keV are shown and discussed. KW - Micro-XAS KW - Compound refractive lens PY - 2012 DO - https://doi.org/10.1039/c2ja30130j SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 10 SP - 1803 EP - 1808 PB - Royal Society of Chemistry CY - London AN - OPUS4-26790 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Constantinescu, B. A1 - Vasilescu, A. A1 - Stan, D. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Buzanich, Günter A1 - Ceccato, D. A1 - Oberländer-Târnoveanu, E. T1 - Studies on archaeological gold items found in Romanian territory using X-ray-based analytical spectrometry JF - Journal of analytical atomic spectrometry N2 - This paper is an overview of the work developed by our group in the investigations of museum objects and alluvial gold, reflected in a series of studies published between 2000–2011, supplemented with new results, unpublished up-to-date. The X-ray based spectrometric techniques employed range from various X-Ray Fluorescence (XRF) investigations to ion beam analysis, including synchrotron radiation XRF and micro-Particle Induced X-ray Emission. The gold objects discussed are mainly part of the Sarmizegetusa Dacian hoards—spiraled bracelets (armbands) and coins. After obtaining in 2011 the permission of the Romanian authorities to take very small (1–2 mg) samples from the most 'unimportant' areas of the Dacian bracelets and several Koson staters, to analyze them by micro-SR-XRF at BESSY, in February 2012, the investigation of several micro-areas of 17 stater and 28 bracelet samples revealed important micro-structural inhomogeneity, especially in Sn and Cu. The same inhomogeneous micro-structure has been seen in Transylvanian alluvial gold. The analyses revealed details on the fingerprint of geological gold deposits and also the main characteristics of ancient gold metallurgy procedures used by the Dacians: a relatively low temperature (lower than Au melting point) and hammering during heating to obtain an ingot through sintering. The use of the sintering procedure was proved for the spiraled bracelets and the Koson without monogram coins, a tradition starting in the Bronze Age in Transylvanian gold processing. The existence of micro-inclusions of Ta-minerals in alluvial gold was also detected, explaining Ta trace presence in the artifacts from the Pietroasa hoard. KW - Micro-SR-XRF KW - Micro-PIXE KW - Archaeometry KW - Gold KW - Romania PY - 2012 DO - https://doi.org/10.1039/c2ja30158j SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 12 SP - 2076 EP - 2081 PB - Royal Society of Chemistry CY - London AN - OPUS4-26991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, M. A1 - Scharf, O. A1 - Novak, S. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Hischenhuber, P. A1 - Buzanich, Günter A1 - Meyer, A. A1 - Lopez, V. A1 - McIntosh, K. A1 - Streli, C. A1 - Havrilla, G. A1 - Fittschen, U. T1 - Shading in TXRF: calculations and experimental validation using a color X-ray camera JF - Journal of Analytical Atomic Spectrometry N2 - Absorption effects in total reflection X-ray fluorescence (TXRF) analysis are important to consider, especially if external calibration is to be applied. With a color X-ray camera (CXC), that enables spatially and energy resolved XRF analysis, the absorption of the primary beam was directly visualized for mL-droplets and an array of pL-droplets printed on a Si-wafer with drop-on-demand technology. As expected, deposits that are hit by the primary beam first shade subsequent droplets, leading to a diminished XRF signal. This shading effect was quantified with enhanced precision making use of sub-pixel analysis that improves the spatial resolution of the camera. The measured absorption was compared to simulated results using three different model calculations. It was found they match very well (average deviation < 10%). Thus errors in quantification due to absorption effects can be accounted for in a more accurate manner. KW - absorption KW - X-ray Fluorescence analysis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-359000 DO - https://doi.org/10.1039/C5JA00127G IS - 10 SP - 2184 EP - 2193 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-35900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Curado, Jessica A1 - Radtke, Martin A1 - Buzanich, Günter A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Guttler, R.A.S. A1 - Rizzutto, M.A. T1 - μ-SRXRF characterization of Brazilian emeralds JF - Journal of physics / Conference series N2 - The aim of the present study is to characterize emeralds from different mines of Brazil by using Synchrotron Radiation X-ray Fluorescence Microanalysis (µ-SRXRF). The advantage of this technique is that we can analyze a homogeneous, inclusion free area of the stone with the microbeam to distinguish the elemental fingerprint according to the provenance of the emerald. A total of 47 samples belonging to 5 different Brazilian mines were studied in this work and 28 elements were identified. By means of Principal Component Analysis (PCA) it is possible to build different groups according to the provenance of the stones, which allows to assign samples of unknown origin to the according mine. T2 - 22nd International congress on X-ray optics and microanalysis CY - Hamburg, Germany DA - 02.09.2013 KW - µ-SRXRF KW - BAMline KW - Emeralds KW - Geoscience PY - 2014 DO - https://doi.org/10.1088/1742-6596/499/1/012016 SN - 1742-6588 SN - 1742-6596 VL - 499 SP - 012016-1 EP - 012016-5 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-30541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rakotondrajoa, Andrianiaina A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vincze, L. A1 - Raboanary, R. T1 - Improvement of PLS regression-based XRF spectroscopy quantification using multiple step procedure and Monte Carlo simulation JF - X-ray spectrometry N2 - 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. KW - SR-microXRF KW - Quantification KW - PLS KW - Monte Carlo PY - 2013 DO - https://doi.org/10.1002/xrs.2479 SN - 0049-8246 VL - 42 IS - 4 SP - 183 EP - 188 PB - Wiley CY - Chichester AN - OPUS4-30225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Buzanich, Günter A1 - Curado, Jessica A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Scharf, O. T1 - Slicing - a new method for non destructive 3D elemental sensitive characterization of materials JF - Journal of analytical atomic spectrometry N2 - Recent advances in synchrotron sources and detector technology have led to substantial improvements in spatial resolution and detection limits for X-ray fluorescence analysis (XRF). However, the non-destructive three-dimensional elemental sensitive characterization of samples remains a challenge. We demonstrate the use of the so-called 'Color X-ray Camera' (CXC) for 3D measurements for the first time. The excitation of the sample is realized with a thin sheet-beam. The stepwise movement of the sample allows getting the elemental distribution for each layer with one measurement. These layers can be combined to a full 3D dataset for each element afterwards. Since the information is collected layer by layer, there is no need to apply reconstruction techniques, which quite often are the reason for artifacts in the results achieved by computed tomography (CT). The field of applications is wide, as the 3D elemental distribution of a material contains clues to processes inside the samples from a variety of origins. The technique is of special interest and well suited for biological specimens, because their light matrix minimizes restricting absorption effects. Measurement examples of a hornet and the teeth of a Sorex araneus are shown. KW - SR-microXRF KW - 3D KW - CXC PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-324330 DO - https://doi.org/10.1039/c4ja00085d SN - 0267-9477 SN - 1364-5544 VL - 29 IS - 8 SP - 1339 EP - 1344 PB - Royal Society of Chemistry CY - London AN - OPUS4-32433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -