Organised and chaired by Nick Marsh.
Our Exhibitors are invited to present a quick fire overview of the latest commercial developments in XRF and sample preparation, to encourage delegates to visit their stands for further information. Just four minutes "without hesitation, deviation or repetition"! In fairness to all, strict time keeping will be maintained. Please raise any questions and ask for details at the exhibitors' stands during the breaks.
Running Order: To be drawn by lot nearer the meeting.
Author: Ros Schwarz, Retired.
The DOT series offered four very different materials for participants to analyse and has provided a snapshot of real-life capabilities of XRF. This short talk gives a personal view of the important issues; highlighting the difficulties of analysing unusual materials, sample pre-treatment and preparation and discrepancies between XRF and ICP-MS values for trace elements
Author: Dr. Tony Bell, Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield, S1 1WB, UK.
Tel: +441142253401 Fax: +441142254449 Anthony.Bell@shu.ac.uk www.shu.ac.uk/about-us/our-people/staff-profiles/tony-bell
Abstract
After a 30 year career in X-Ray Diffraction, I moved in 2015 to Sheffield Hallam University to run a combined X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) laboratory. Since then I have discovered just how useful XRF can be for an XRD person. This talk will illustrate how XRD can be complementary for XRF analyses.
Author: Kevin Talmage, Rigaku.
Abstract
Applying XRF as an on line measurement is of interest as a means of keeping a process in control and reducing costs. This presentation is a summary of some of the adaptions of this technique to an on-line situation with a short discussion of some of the criteria that need to be addressed.
Author: Thierry Théato, SPECTRO Analytical Instruments GmbH, Boschstraße 10, 47533 Kleve, Germany
Abstract
Classical Fundamental parameter as described from Sherman1 as well as Shiraiwa and Fujino2 are suitable for either thick or thin samples as the effect of instrumental geometry, pointed out by Weber3, are neglected in the traditional models. The influence of the geometry on analytical results will be shown for organic and oxidic samples and how this effects samples of varying small masses. A modification of the mentioned algorithms will be presented to improve the accuracy of the analytical results for small mass samples with a typical EDXRF geometry. Furthermore, the use of incoherent Co K scattering in combination with these modifications enables new applications as presented for the analysis of Sulfur and other trace elements in used vegetable oil.
References:
1. Sherman J., Spectrochim Acta 7, 283-306 (1955)
2. Shiraiwa T., Fujino N., Jpn J Appl Phys 5, 886-899 (1966)
3. Weber A., XRS 12,1, 11-18 (1983)
Author: Frederic Davidts, XRF Scientific. 282 Av. de Roodebeek, 1030 Brussels, Belgium
tel:+32 2 762 77 12 mob: +32 478 329 744 frederic.davidts@xrfscientific.com www.xrfscientific.com
Abstract
To increase throughput and safety, a lot of laboratories make the choice to automate their sample preparation. But a complete automation using robotics is often expensive and requires regular adjustments.
The xrWeigh Carousel has been developed for fast weighing of the flux while removing a repetitive task from your laboratory at a fraction of the price of a complete automation.
In a typical laboratory environment the introduction of the xrWeigh Carousel will reduce the time needed for manual weighing by up to 75% while improving accuracy and traceability.
The bottle switching system makes it easy and cost effective to operate the flux storage.
Author: Kenneth D.M. Harris, School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales HarrisKDM@cardiff.ac.uk
Abstract
Structure determination of organic materials directly from powder X-ray diffraction (XRD) data is nowadays carried out extensively by researchers in both academia and industry [1,2]. The majority of work in this field is focused on exploiting the direct-space strategy for structure solution [3] followed by Rietveld refinement. Although these techniques are now readily accessible and relatively straightforward to use, it is essential that the structural results obtained from such analysis are subjected to rigorous scrutiny before they can be assigned as incontrovertibly correct, and the lecture will present an overview of important issues that must be given careful attention in validating the correctness of crystal structures determined using these techniques.
The lecture will discuss several different aspects of validation that are important with regard to: (i) validation of the correct structural model for use in direct-space structure solution calculations, and (ii) validation of the final structure obtained from Rietveld refinement. Specific issues that will be discussed include verification of the correct assignment of hydrogen atom positions [4], tackling structure solution of disordered materials within the direct-space structure solution strategy, and the direct use of solid-state NMR data within the validation protocols.
The lecture will emphasize the significant advantages that can be gained by the synergistic utilization of information obtained from other experimental and computational techniques as an important component within the validation of structures determined from powder XRD data [5-9], focusing on the important roles that solid-state NMR spectroscopy and computational strategies (particularly periodic DFT methods) may play in achieving robust validation of crystal structures determined from powder XRD data.
References:
1. K.D.M. Harris, M. Tremayne, B.M. Kariuki, Angew. Chemie Int. Ed., 2001, 40, 1626.
2. K.D.M. Harris, Top. Curr. Chem., 2012, 315, 133.
3. K.D.M. Harris, M. Tremayne, P. Lightfoot, P.G. Bruce, J. Am. Chem. Soc., 1994, 116, 3543.
4. E.J. MacLean, K.D.M. Harris, B.M. Kariuki, S.J. Kitchin, R.R. Tykwinski, I.P. Swainson, J.D. Dunitz, J. Am. Chem. Soc., 2003, 125, 14449.
5. D.V. Dudenko, P.A. Williams, C.E. Hughes, O.N. Antzutkin, S.P. Velaga, S.P. Brown, K.D.M. Harris, J. Phys. Chem. C, 2013, 117, 12258.
6. P.A. Williams, C.E. Hughes, K.D.M. Harris, Angew. Chemie Int. Ed., 2015, 54, 3973.
7. K.I. Shivakumar, Y. Yan, C.E. Hughes, D.C. Apperley, K.D.M. Harris, G.J. Sanjayan, Cryst. Growth Des., 2015, 15, 1583.
8. A.E. Watts, K. Maruyoshi, C.E. Hughes, S.P. Brown, K.D.M. Harris, Cryst. Growth Des., 2016, 16, 1798.
9. C.E. Hughes, G.N.M. Reddy, S. Masiero, S.P. Brown, P.A. Williams, K.D.M. Harris, Chem. Sci., 2017, 8, 3971.
Author: Dr. Rainer Schramm, FLUXANA GmbH & Co. KG, Borschelstr.3, 47551 Bedburg-Hau, Germany
Tel. +49 2821 99732-0, Fax +49 2821 99732-29, www.fluxana.com, info@fluxana.com
Abstract
As a result of a research study with the university Rhine-Waal different crucible materials were tested for xrf fusion technique as alternatives for platinum crucibles.
While platinum/gold crucibles are common in xrf fusion technique there are still sample materials which partly attack the crucible material or even mechanically destroy the whole crucible.
Especially samples with metallic particles (like aluminium) or samples with significant sulphide content show such an effect.
Based on the research study the use of quartz crucibles was tested as best alternative crucible material in the real laboratory work.
A general calibration for the analysis of 14 elements was performed by using quartz crucibles in the fully automated VITRIOX electric fusion machine. To help oxidizing metal particles and reduced species the flux/sample recipe was completed by using an additional oxidizer.
As control and validation samples different slags from steel industry were used.
Author: Joanna F Collingwood [1], James Everett [2], and Neil Telling [2].
[1] School of Engineering, University of Warwick; [2] Institute of Science and Technology in Medicine, Keele University.
Abstract
The metabolism of iron in the human brain is essential for health, but also a source of damage if iron is incorrectly handled. There is a long-standing debate about whether incompletely-bound reactive iron contributes to toxic processes in brain disorders such as Alzheimer’s disease. The vast majority of mineralized iron in the brain is normally in a ferrihydrite-like ferric form, encapsulated in the protein ferritin.
We used synchrotron X-ray fluorescence analysis to show the presence of the mixed-valence iron oxide magnetite in a region of the human brain exhibiting significant Alzheimer’s disease pathology in the form of amyloid plaques. Subsequently we also saw evidence for the formation of magnetite in a transgenic model of Alzheimer’s disease that overproduces amyloid.
In this talk we will show how a complementary set of synchrotron spectromicroscopy techniques, including XRF, has now allowed us to demonstrate with excellent chemical sensitivity and specificity that both unbound and mineralized iron is chemically reduced to a reactive form at physiological pH when in the vicinity of the aggregating amyloid protein. We hypothesize that this process accounts for the former observations of magnetite in amyloid-rich brain tissue, and that it contributes to the observed toxicity of aggregating amyloid peptides in the Alzheimer’s disease brain.
Author: Mike Dobby Analytical Consultant, Sheffield
+44 7432052193 mike@mikedobby.com
Abstract
This talk will be an overview of micro beam XRF and look at how modern systems may be used in a wide variety of industries, research and museums.
With virtually no sample preparation, ability to analyse in air, helium or vacuum, work with large samples, get excellent spatial resolution with high count rates and fast scan rates this technique can be considered the one stop shop for XRF. You can also use those pesky diffraction peaks to provide useful data.
Author: Keith Tame, SciMed
Abstract
The study of phase transitions between the various solid states is important to the pharmaceutical and other industries. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) have proven to be two of the most useful techniques for this research. Since these methods are complementary to one another, measurements using both XRD and DSC have become a popular way of studying the thermal reactions of solids. The usual approach is to sequentially perform the two measurements; however, this can cause problems as exact experimental conditions may be difficult to replicate. Such problems can be overcome by simultaneously performing XRD and DSC measurements on the same sample. This talk will investigate a few examples of this and highlight the benefits of doing this analysis simultaneously.
Author: Dr Graeme Hansford – Department of Physics and Astronomy, University of Leicester.
Abstract:
Handheld XRD is enabled by the application of energy-dispersive XRD (EDXRD) in a back-reflection geometry which leads to insensitivity to the sample morphology. Samples can be analysed with no preparation of the material at all, including non-planar surfaces. Although the resolution afforded by EDXRD is low relative to conventional benchtop or floor-mounted diffractometers, the benefits of ¬in situ analysis on a short timescale opens up a range of potential applications. Furthermore, since metals and alloys tend to have simple, high-symmetry crystal structures, their diffraction peaks are well-spaced and can generally be resolved using EDXRD. Using a prototype instrument developed at the University of Leicester, the potential capabilities of handheld XRD in metals analysis has been investigated by testing with a wide range of metals and alloys. To date, testing has covered a total of 76 samples, including alloys based on aluminium, copper, nickel and titanium as well as standard-grade and research steels. Results will be presented illustrating the ability of the prototype instrument to determine phase composition and unit cell dimensions, and to extract texture information.