scholarly journals Synchrotron radiation micro X-ray fluorescence spectroscopy of thin structures in bone samples: comparison of confocal and color X-ray camera setups

2017 ◽  
Vol 24 (1) ◽  
pp. 307-311 ◽  
Author(s):  
M. Rauwolf ◽  
A. Turyanskaya ◽  
A. Roschger ◽  
J. Prost ◽  
R. Simon ◽  
...  

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 BESSY-II) setup. As zinc is a trace element of special interest in bone, the setups were optimized for its detection. The setups were compared with respect to count rate, required measurement time and spatial resolution. It was demonstrated that the ideal method depends on the element of interest. Although for Ca (a major constituent of the bone with a low energy of 3.69 keV for its Kα XRF line) the color X-ray camera provided a higher resolution in the plane, for Zn (a trace element in bone) only the confocal SR-µXRF setup was able to sufficiently image the distribution.

Author(s):  
R. Beeuwkes ◽  
A. Saubermann ◽  
P. Echlin ◽  
S. Churchill

Fifteen years ago, Hall described clearly the advantages of the thin section approach to biological x-ray microanalysis, and described clearly the ratio method for quantitive analysis in such preparations. In this now classic paper, he also made it clear that the ideal method of sample preparation would involve only freezing and sectioning at low temperature. Subsequently, Hall and his coworkers, as well as others, have applied themselves to the task of direct x-ray microanalysis of frozen sections. To achieve this goal, different methodological approachs have been developed as different groups sought solutions to a common group of technical problems. This report describes some of these problems and indicates the specific approaches and procedures developed by our group in order to overcome them. We acknowledge that the techniques evolved by our group are quite different from earlier approaches to cryomicrotomy and sample handling, hence the title of our paper. However, such departures from tradition have been based upon our attempt to apply basic physical principles to the processes involved. We feel we have demonstrated that such a break with tradition has valuable consequences.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 459
Author(s):  
Johannes Becher ◽  
Sebastian Weber ◽  
Dario Ferreira Sanchez ◽  
Dmitry E. Doronkin ◽  
Jan Garrevoet ◽  
...  

Structure–activity relations in heterogeneous catalysis can be revealed through in situ and operando measurements of catalysts in their active state. While hard X-ray tomography is an ideal method for non-invasive, multimodal 3D structural characterization on the micron to nm scale, performing tomography under controlled gas and temperature conditions is challenging. Here, we present a flexible sample environment for operando hard X-ray tomography at synchrotron radiation sources. The setup features are discussed, with demonstrations of operando powder X-ray diffraction tomography (XRD-CT) and energy-dispersive tomographic X-ray absorption spectroscopy (ED-XAS-CT). Catalysts for CO2 methanation and partial oxidation of methane are shown as case studies. The setup can be adapted for different hard X-ray microscopy, spectroscopy, or scattering synchrotron radiation beamlines, is compatible with absorption, diffraction, fluorescence, and phase-contrast imaging, and can operate with scanning focused beam or full-field acquisition mode. We present an accessible methodology for operando hard X-ray tomography studies, which offer a unique source of 3D spatially resolved characterization data unavailable to contemporary methods.


2020 ◽  
Author(s):  
O. V. Gorchakova ◽  
Yu. P. Kolmogorov ◽  
V. N. Gorchakov ◽  
G. A. Demchenko ◽  
S. N. Abdreshov

2014 ◽  
Vol 47 (6) ◽  
pp. 1882-1888 ◽  
Author(s):  
J. Hilhorst ◽  
F. Marschall ◽  
T. N. Tran Thi ◽  
A. Last ◽  
T. U. Schülli

Diffraction imaging is the science of imaging samples under diffraction conditions. Diffraction imaging techniques are well established in visible light and electron microscopy, and have also been widely employed in X-ray science in the form of X-ray topography. Over the past two decades, interest in X-ray diffraction imaging has taken flight and resulted in a wide variety of methods. This article discusses a new full-field imaging method, which uses polymer compound refractive lenses as a microscope objective to capture a diffracted X-ray beam coming from a large illuminated area on a sample. This produces an image of the diffracting parts of the sample on a camera. It is shown that this technique has added value in the field, owing to its high imaging speed, while being competitive in resolution and level of detail of obtained information. Using a model sample, it is shown that lattice tilts and strain in single crystals can be resolved simultaneously down to 10−3° and Δa/a= 10−5, respectively, with submicrometre resolution over an area of 100 × 100 µm and a total image acquisition time of less than 60 s.


1997 ◽  
Vol 297 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Beathe Thu ◽  
Gudmund Skjåk-Bræk ◽  
Fulvio Micali ◽  
Franco Vittur ◽  
Roberto Rizzo

Author(s):  
K. Janssens ◽  
F. Adams ◽  
M.L. Rivers ◽  
K.W. Jones

Micro-SXRF (Synchrotron X-ray Fluorescence) or micro-SRIXE (Synchrotron Radiation Induced X-ray Emission) is a microanalytical technique which combines the sensitivity of more conventional microchemical methods such as Secondary Ion Microscopy (SIMS) and μ-PIXE (Proton Induced X-ray Emission) with the non-destructive and quantitative character of X-ray fluorescence analysis. The detection limits attainable at current SXRF-facilities are situated in the ppm (and in favourable cases the sub-ppm) range. The sensitivity of SRIXE can be used advantageously in individual particle analysis. This type of analysis is used, e.g., for studying sources of athmospheric pollution. Analysis of standard NIST micro-spheres at the NSLS-SRIXE facility yielded minimum detection limits in the 1 to 100 ppm range for particle sizes of around 10 to 30 μm.An interesting approach to individual particle characterisation is by means of electron microprobe analysis (EPMA). By using the backscattered electron signals, in an automated fashion, particles can be easily located on a filter substrate and their size and shape determined.


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