Christina Streli

TU Wien | TU Wien · Institute of Atomic and Subatomic Physics

Objective The objective of the study was to specify the thickness of Zn and Pb accumulation within the tidemark (TM), a narrow structure between the non-calcified and the calcified articular cartilage. It is considered an active or resting calcification front. This banded structure of the cartilage-bone interface is known to undergo changes in oste...

Confocal micro-x-ray fluorescence (μXRF) is a powerful tool to analyze the spatial distribution of major, minor, and trace elements in three dimensions. Typical (confocal) μXRF measurements in the lab use polychromatic excitation, complicating quantification and fundamental parameter-based corrections and furthermore deteriorating peak-to-backgroun...

A commercial Empyrean X-ray diffractometer was adapted for combined grazing incidence X-ray fluorescence analysis (GIXRF) measurements with X-ray reflectivity (XRR) measurements. An energy-dispersive silicon drift detector was mounted and integrated in the angle-dependent data acquisition of the Empyrean. Different monochromator/X-ray optics units...

X-ray imaging methods are used in many fields of research, as they allow a non-destructive investigation of the elemental content of various samples. As for every imaging method, for X-ray imaging the optics are of crucial importance. However, these optics can be very expensive and laborious to build, as the requirements on surface roughness and pr...

jsfa10463-sup-0001-supinfo.docx Figure S1. Spectrum of a clean reflector Table S1. TXRF analysis of the certified reference material NIST 1640 (Trace Elements in Natural Water)

Liposomes containing copper and the copper ionophore neocuproine were prepared and characterized for in vitro and in vivo anticancer activity. Thermosensitive PEGylated liposomes were prepared with different molar ratios of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and hydrogenated soybean phosphatidylcholine (HSPC) in the presence of...

BACKGROUND: Elemental composition of herbal infusions and teas is insufficiently investigated, but could be potentially used for defining fingerprints for individual herbal/tea infusions, differentiation of botanical families, influence of packaging, and other parameters. The objective of this study was to determine elemental composition including...

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Gadolinium-based contrast agents (GBCAs) are frequently used in patients undergoing magnetic resonance imaging. In GBCAs gadolinium (Gd) is present in a bound chelated form. Gadolinium is a rare-earth element, which is normally not present in human body. Though the blood elimination half-life of contrast agents is about 90 minutes, recent studies d...

Strontium‐based medications, such as strontium ranelate, have been suggested to have therapeutic effects in patients with osteoporosis. Strontium salts available off‐shelf in stores across North America are assumed to provide similar effects as strontium ranelate and thus should lead to similar distributions of elemental strontium incorporated in b...

Clinical evidence shows that following initial response to treatment, drug-resistant cancer cells frequently evolve and, eventually, most tumors become resistant to all available therapies. We compiled a focused library consisting of >500 commercially available or newly synthetized 8-hydroxyquinoline (8OHQ) derivatives whose toxicity is paradoxical...

Stabilization capacity of 5% by weight lignite added in three particle size ranges (<0.5; 0.5–1.0 and 1.0–2.0 mm) to acidic (pH = 5.0) or calcareous (pH = 7.7) sandy soil samples of <2 mm grain size artificially contaminated with 375 mg/kg Cr(III) was assessed through fit-for-purpose leaching tests performed with CH3COOH, NH2OH·HCl and EDTA. About...

The imaging with X-rays is a challenging field, due to the optical properties of X-rays. The fabrication of the appropriate optics is usually expensive and requires an elaborate manufacturing process. One simpler and less expensive possibility of imaging high energy radiation is coded aperture imaging, a technique well established in astrophysics a...

Our group employs micro- and nano-X-ray fluorescence spectrometry (XRF)for the investigation of bone tissue. The manuscript presents the results of 3 various projects, in which spatial distribution of trace elements in bone samples was studied. The first study investigated the distribution of the elemental constituents of Mg-based implants at vario...

In this work a new setup for time-resolved dispersive-XAFS measurements is presented. This stable and scanningless setup provides both time- and lateral-resolved XAFS experiments in a ‘single-shot’. It allows a straightforward adjustment for probing different elements that cover many relevant applications for material characterization. A broadband...

This article presents results from an experimental setup for a dual energy-band vacuum spectrometer for total-reflection X-ray fluorescence analysis allowing simultaneous efficient excitation of low, medium, and high Z elements. The spectrometer is equipped with an air-cooled 35 W low power Rh X-ray tube and a 17 mm² silicon drift detector with a t...

Total reflection X-ray fluorescence (TXRF) is ideally suited for the inspection of silicon wafer surfaces in the ultra trace regime. Detection limits in the range of 10¹⁰ atoms⋅ cm⁻² for metals are achievable by straight TXRF. The determination of surface contaminations on silicon wafers is of great importance to the semiconductor industry as the p...

An X-ray fluorescence setup has been tested on the B16 beamline at the Diamond Light Source synchrotron with two different excitation energies (12.7 and 17 keV). This setup allows the scanning of thin samples (thicknesses up to several micrometers) with a sub-micrometer resolution (beam size of 500 nm × 600 nm determined with a 50 µm Au wire). Sens...

Organic light-emitting diodes (OLEDs) continue to attract research interest due to their application in bright displays and solid-state lighting. The highest efficiency values are reached with multilayer devices. The morphology of these layers is important for device performance. A current field of development is the application of solution-based d...

The aim of the work is to present a systematic evaluation of the analytical capabilities of the new X-ray fluorescence facility jointly operated between the International Atomic Energy Agency and the Elettra Sincrotrone Trieste for multipurpose total reflection X-ray fluorescence analysis. The analytical performance of the XRF beamline end-station...

In the present study, several Cu chelators [2,2'-biquinoline, 8-hydroxiquinoline (oxine), ammonium pyrrolidinedithiocarbamate (APDTC), Dp44mT, dithizone, neocuproine] were used to study Cu uptake, depletion and localization in different cancer cell lines. To better understand the concentration dependent fluctuations in the Cu intracellular metal co...

This paper investigates in detail a sample preparation procedure for the total-reflection X-ray fluorescence (TXRF) analysis of airborne particles using a three-stage Dekati™ PM10 cascade impactor. The impactor was modified in such a way, that 30 mm diameter quartz reflectors suitable for TXRF spectrometers can be inserted as collection plates belo...

The confocal µXRF spectrometer of Atominstitut (ATI) was transported and set up at the X-Ray Fluorescence beamline at Elettra - Sincrotrone Trieste. It was successfully adjusted to the incoming beam (9.2 keV). Test measurements on a free-standing Cu wire were performed to determine the size of the focussed micro-beam (non-confocal mode, 56×35 µm²)...

Matrix-assisted laser desorbtion/ionisation mass spectrometric imaging (MALDI MSI) is a technique providing localized information on intact molecules in a sample. Micro X-ray fluorescence (µXRF) imaging allows to examine the spatial distribution of elements in a sample without any morphological changes. These methods have already been applied separ...

Fine aerosol particles with aerodynamic diameter equal or <2.5 μm (PM2.5) have been collected from industrial and residential areas of Greater Cairo, Egypt during two different seasons namely; autumn 2014 and winter 2014/2015. Energy dispersive X-ray fluorescence (EDXRF) analysis utilizing polarization geometry and three different secondary targets...

Modern imaging sensors allow for high granularity optical readout of radiation detectors such as MicroPattern Gaseous Detectors (MPGDs). Taking advantage of the high signal amplification factors achievable by MPGD technologies such as Gaseous Electron Multipliers (GEMs), highly sensitive detectors can be realised and employing gas mixtures with str...

Due to the remarkable increasing of the mass concentrations of suspended particulate matter (SPM) as an air pollution indicator in Greater Cairo-Egypt, regular sampling during autumn 2014 and winter 2014/2015 seasons has been performed from industrial and residential areas. It was found that the average mass concentrations of the SPM collected from...

Gaseous Electron Multipliers (GEM) are well known for stable operation at high particle fluxes. We present a study of the intrinsic limits of GEMdetectors when exposed to very high particle fluxes of the order of MHz/mm2. We give an interpretation to the variations of the effective gain, which, as a function of the particle flux, first increases an...

Combining strong signal amplification made possible by Gaseous Electron Multipliers (GEMs) with the high spatial resolution provided by optical readout, highly performing radiation detectors can be realized. An optically read out GEM-based Time Projection Chamber (TPC) is presented. The device permits 3D track reconstruction by combining the 2D pro...

A method has been developed for the quantitative elemental analysis of Mentha longifolia L. leaves collected from different cities in Saudi Arabia using total reflection X-ray fluorescence. Using a microwave digestion system, 100 mg of each sample were completely digested using 3 mL of nitric acid and 2 mL of hydrogen peroxide. The stabilization of...

Total arsenic (As) as well as As(III) and As(V) species were monitored in drinking water with elevated As content sampled at waterworks of four settlements located in Hungary by means of on-site, solid phase extraction with a strong anion exchanger followed by As determination by either high-resolution continuum source graphite furnace atomic absor...

This review describes advances in the XRF group of techniques published approximately between April 2016 and March 2017. With technique maturity, it is the sample rather than the instrumentation that limits its wider development, so regular readers are advised to consult our companion application updates for advances in XRF related to specific samp...

The optical and electrical properties of transparent conducting oxide (TCO) thin films are strongly linked with the structural and chemical properties such as elemental depth profile. In R&D environments, the development of non-destructive characterization techniques to probe the composition over the depth of deposited films is thus necessary. The...

Abnormal tissue levels of certain trace elements such as zinc (Zn) were reported in various types of cancer. Little is known about the role of Zn in osteosarcoma. Using confocal synchrotron radiation micro X-ray fluorescence analysis, we characterized the spatial distribution of Zn in high-grade sclerosing osteosarcoma of nine patients (four women/...

In this paper, the results of a feasibility study, investigating a new quantification method of directly collected aerosol samples, are shown. As sampling substrates, quartz reflectors suitable for total reflection X-ray fluorescence analysis were used, and the spot patterns produced by a three-stage Dekati impactor were considered. For calibration...

In the quest for finding the ideal synchrotron-radiation-induced imaging method for the investigation of trace element distributions in human bone samples, experiments were performed using both a scanning confocal synchrotron radiation micro X-ray fluorescence (SR-µXRF) (FLUO beamline at ANKA) setup and a full-field color X-ray camera (BAMline at B...

The various types of spectrometers used for X-ray fluorescence spectroscopy are summarized and the widespread applications of the technique are surveyed.

Evaluation of in vitro cytotoxicity of several Cu chelating agents - 2,2′-biquinoline, 8-hydroxyquinoline (oxine), ammonium pyrrolidinedithiocarbamate (APDTC), di-2-pyridylketone-4,4,-dimethyl-3-thiosemicarbazone (Dp44mT), dithizone and neocuproine – on HT-29 human colon adenocarcinoma as well as long term in vitro cytostatic effect were assessed i...

This study investigated the distribution of the elemental constituents of Mg-based implants at various stages of the degradation process in surrounding bone tissue, with a focus on magnesium (Mg), as the main component of the alloy, and yttrium (Y), due to its potential adverse health effects. The measurements were performed on the implant-bearing...

Atomic layer deposition (ALD) coatings are used in this work to achieve beneficial effects on the surface of CoCrMo alloys used for biomedical applications. Model experiments of implantation into animal bone tissue are performed with uncoated and TiO2 coated samples. Micro X-ray fluorescence is used to map the elemental composition of samples. Resu...

This review describes advances in the XRF group of techniques published approximately between April 2015 and March 2016. Fundamental contributions in the instrumentation sections include the development of synchrotron radiation sources, semiconductor design technology and evaluating the quality of in situ hand-held XRF results. A bench top TXRF spe...

HR-CS-GFAAS methods were developed for the fast determination of Cu in domestic and commercially available Hungarian distilled alcoholic beverages (called pálinka), in order to decide if their Cu content exceeds the permissible limit, as legislated by the WHO. Some microliters of samples were directly dispensed into the atomizer. Graphite furnace h...

European Spallation Source instruments like the macromolecular diffractometer (NMX) require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters i...

Abnormal tissue levels of certain trace elements such as Zinc (Zn) were reported in various types of cancer. Little is known about the role of Zn in osteosarcoma. Using confocal synchrotron radiation micro X-ray fluorescence analysis, we characterized the spatial distribution of Zn in high-grade (G3) sclerosing osteosarcoma of nine patients (4 f/5...

Contemporary elemental imaging techniques are greatly contributing into the bone research. Synchrotron radiation induced confocal micro x-ray fluorescence technique (SR-μXRF) was employed for the analysis, being the most powerful and sufficient tool in detection and characterization of trace element distributions in bone tissue. Manganese (Mn), as...

Nanoparticulate ZnO is one of the most commonly applied nanomaterials. As ZnO is more soluble than many other oxide nanoparticles, its toxicity beyond the nanoparticle-specific effects can be attributed to the dissolved ionic zinc. The investigation of uptake and toxicity of nano-ZnO in the plant-feeding nematode, Xiphinema vuittenezi, which was us...

An automatic sample changer chamber for total reflection X-ray fluorescence (TXRF) and X-ray absorption near-edge structure (XANES) analysis in TXRF geometry was successfully set up at the BAMline at BESSY II. TXRF and TXRF-XANES are valuable tools for elemental determination and speciation, especially where sample amounts are limited (<1 mg) and c...

Grazing incidence XRF (GIXRF) is a very surface sensitive, nondestructive analytical tool making use of the phenomenon of total external reflection of X-rays on smooth polished surfaces. In recent years the method experienced a revival, being a powerful tool for process analysis and control in the fabrication of semiconductor based devices. Due to...

Fast- and slow-proliferating human adenocarcinoma colorectal cells, HT-29 and HCA-7, respectively, overloaded with transferrin (Tf), Fe(III) citrate, Fe(III) chloride and Fe(II) sulfate were studied by synchrotron radiation total-reflection X-ray spectrometry (TXRF), TXRF-X-ray absorption near edge structure (TXRF-XANES), and micro-X-ray fluorescen...

A compact TXRF spectrometer with low power Cr and Rh X-ray tubes and single sample chamber, detector and power supply was installed in Fuel Chemistry Division. The spectrometer does not require LN2 cooling for detector and water cooling for anodes of X-ray tubes. These features make it very compact and well suited for a Radiochemistry laboratory. T...

We show that Atomic Layer Deposition is a suitable coating technique to prevent metal diffusion from medical implants. The metal distribution in animal bone tissue with inserted bare and coated Co–Cr alloys was evaluated by means of micro X-ray fluorescence mapping. In the uncoated implant, the migration of Co and Cr particles from the bare alloy i...

Graphene is a single layer of carbon atoms arranged in a honeycomb lattice with remarkable mechanical and electrical properties. Regarded as the thinnest and narrowest conductive mesh, it has drastically different transmission behaviours when bombarded with electrons and ions in vacuum. This property, if confirmed in gas, may be a definitive soluti...

A comprehensive study, supported by systematic measurements and numerical computations, of the intrinsic limits of multi-GEM detectors when exposed to very high particle fluxes or operated at very large gains is presented. The observed variations of the gain, of the ion back-flow, and of the pulse height spectra are explained in terms of the effect...

European Spallation Source instruments like the macromolecular diffractometer, NMX, require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters i...

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 μL-droplets and an array of pL-droplets pri...

This review describes advances in the XRF group of techniques published approximately between April 2014 and March 2015 and is therefore restricted to a selection of papers featuring developments in the XRF armoury. An active topic during this review period was that of imaging techniques and, more particularly of micro X-ray fluorescence spectromet...

The extension of the detectable elemental range with Total Reflection X-ray Fluorescence (TXRF) analysis is a challenging task. In this paper, it is demonstrated how a TXRF spectrometer is modified to analyze elements from carbon to uranium. Based on the existing design of a vacuum TXRF spectrometer with a 12 specimen sample changer, the following...

Inorganic arsenic species in ambient particulate matter (PM10 and PM2.5) have been determined in an urban area, in the vicinity of a metallurgical industrial plant. The developed high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC/ICP-MS) method allows monitoring of particulate As(III) and As(V)-species, with a...

The aim of this work was to compare different excitation modes for the analysis of light elements from carbon (Z = 6) upwards using a total reflection X-ray fluorescence analysis (TXRF) vacuum chamber which allows the attachment of different X-ray tubes and detectors. In the first set of experiments, two water-cooled high-power X-ray tubes with Cr...

The distribution of elements in sauropod humeri and femora was determined by micro-X-ray- fluorescence analysis (µ-XRF). Element distribution maps enable correlations between bone architecture and spatial distribution of the chemical elements. The investigations reveal no significant macroscopic gradients in the element distribution across the foss...