X-ray Fluorescence Microprobe Technique Research Articles

Data on biomechanics and elemental maps of dental implant-bone complexes in rats.

Implant-bone biomechanics and mechanoadaptation of peri‑implant tissue in space (around and along the length of an implant) and time (3-, 11-, and 24-day following implantation) are important for functional osseointegration of dental implants. Spatiotemporal shifts in biomechanics of implant-bone complex in rat maxillae were correlated with maximum (tensile) and minimum (compressive) principal strain profiles in peri‑implant tissue using a hybrid model; biomechanics in situ paired with digital volume correlation. Spatiotemporal changes in elemental counts and their association with mineral density of the peri‑implant tissue were mapped using electron dispersive X-ray and X-ray fluorescence microprobe techniques. Data provided within are related to biomechanical testing of an implant-bone complex in situ. Data also highlight the power of correlating elemental colocalization with tension and compression regions of the peri‑implant tissues to explain spatiotemporal mechanoadaptation of implant-bone complexes. Further interpretation of data is provided in “Mechanoadaptive Strain and Functional Osseointegration of Dental Implants in Rats [1].”

On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8μm×3μm beam focus allowing detection down to ppb levels of U in 10s (SR μ-XRF setup) and 70s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10–15μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM–EDX). However, the particles were not visible in washed hair shafts.These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor.

A combination of size-resolved particle samplers and XRF microprobe technique for single particle study

It is important to understand the properties of individual airborne particulates that are determined by the processes of various physicochemical reactions occurring in their generation, transformation, and transport. This study describes the application of the X-ray fluorescence (XRF) microprobe technique to the analysis of size-resolved individual particles as well as the results of an experimental study on the comparison of three different particle collection instruments for single particle analysis: a two-stage filter pack, a low pressure Andersen impactor (LPAI), and a micro-orifice uniform deposit impactor (MOUDI). Though LPAI and MOUDI are relatively suitable for multisize-segregated particles sampling compared with the two-stage filter pack sampler, they can easily form particle clusters and finally these particle clusters impede single particle analysis. Even though more particle mass can be collected without overloading on the substrate using MOUDI, by stage rotating, particles are still deposited and form clusters on the concentric circles. When particles are forming a spot (or other shapes of particle cluster), single particle analysis using the XRF micro-beam technique is restricted to individual particles deposited at the edge of the spot. Thus, the sampling duration time depending on the sampler stage should be adjusted for single particle study.

Elemental Distribution in Individual Rain Droplets Determined by a Combination of the Replication Method and the Synchrotoron Radiation X-ray Fluorescence Microprobe Technique

The main objective of the present study is to specify the chemical properties of individual rain droplets. For this purpose, we have combined the collodion replication method and the SR-XRF microprobe technique. The dry residual materials retained in a single rain droplet, which correspond to the former cloud condensation nuclei and the scavenged particles during droplet falling, were successively reconstructed by the multiple elemental maps using SR-XRF microprobe analytical system. Also the SR-XRF microprobe system allows us to quantify the masses of ultra trace elements in residues of individual rain droplet with fg level. The proposed combination method in the present study is found to be helpful to understand the physicochemical properties of individual rain droplets.

The Application of X-Ray Fluorescence Probe Analysis to the Study of Segregation in Steels

AbstractChemical analysis by the X-ray fluorescence microprobe technique offers potential means for the determination of compositional differences arising from the segregation of elements during the solidification of metals. The dimensional scale of the probe is expected to be suitable for the study of macro segregation and, in coarse-grained cast materials, of interdendritic micro segregation.This paper describes preliminary work carried out to establish analytical sensitivity in respect of some minor constituents present in homogeneous steel samples of known composition. The significance of the results is discussed in relation to the problems of segregation in steel, and it is concluded that the Siemens Kristalloflex IV equipment needs to be adapted for fully focusing operation to achieve the sensitivity required for this work. Details are given of the work so far undertaken in this direction.