Professor Andrew Shortland, Cranfield Forensic Institute, Cranfield University.
Cranfield Forensic Institute includes a significant Group specialising in the analysis of historical objects to answer historical and forensic questions. XRF plays a significant role in this analysis, particularly in triaging large bodies of material to form analytical groups for analysis by other techniques. This presentation shows two applications of XRF in this work, one using benchtop XRF and one handheld. The benchtop work was carried out in conjunction with Bonhams Auctioneers and focuses on the analysis of high-value porcelain, especially European porcelain such as Meissen. The handheld work shows the applicability of XRF to the identification of repairs and later restoration in standing stained-glass windows from the 17th century. Both show that XRF is a valuable tool: that can be applied relatively quickly and easily, so long as the limitations of the technique are understood. XRF analysis of historical glass and glaze.
Organised and chaired by Dave Taylor.
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 three 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: SciMed, Spectro, Niton, SpexEurope, Bruker, Specac, PANalytical, Shimadzu, DSL Datech, XRF Scientific.
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.
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.
Jennifer Horner, Spectro Analytical UK.
Even today, energy dispersive X-ray fluorescence analysis (ED-XRF) is frequently seen as a technique that can only be used for qualitative analysis and not quantitative. Believing ED-XRF is appropriate for analyzing only a few elements is just another prejudice that is no longer valid. Recent advances in ED-XRF technology have led to a true quantum leap: For many applications, commonly reserved for WD-XRF, advanced ED-XRF analyzers now deliver a completely comparable performance. They provide outstanding sensitivity and detection limits — yielding remarkable gains in precision and accuracy. As a consequence, ED-XRF is now recognized by experts as being a proven and reliable technology that meets (and exceeds) the requirements for a wide range of applications. This presentation reviews some of these recent developments and illuminates the potential of modern ED-XRF instruments based on typical applications.
Ros Schwarz, Heather Harrison and Judith Bain.
The results from last year's gypsum participant sample (DOT-3) will be summarised and some issues highlighted. This year we will offer a ferroalloy for analysis. Use it as a training exercise or simply an interesting sample to analyse with confidence if this is your world or a challenge if something new. Pointers will be given as how a commercial laboratory would tackle a sample if outside the usual XRF methods in place.
Paul Vanden Branden, Garry Smith, Scientific and Medical Products Ltd
“The accuracy of an analysis is only as good as the calibration”. This is a commonly-used saying in instrumental analytical chemistry, and it is certainly true of quantitative XRF analysis. In practical scenarios establishing a “perfect” calibration can often be something of a compromise depending on the nature of the sample and the preparation technique being used.
This presentation will give a general review of some of the different calibration strategies available to the analyst, provide examples of their application, and highlight some of the important factors that need to be taken into account to get the best out of them.
Steve Davies, PANalytical.
Small Spot Mapping appears to be becoming the new 'must have' accessory for WDXRF spectrometers. Apart from analysing small spots, is it any use for anything else ?
Charles Shand 1, Renate Wendler 1, Hayleigh Stephenson 2
1 Environmental and Biochemical Sciences, The James Hutton Institute, Aberdeen, UK.
2 School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK.
Scotch whisky makes up around one quarter of the UK’s total food and drinks exports and in 2015 was valued at £3.95 billion for the UK balance of trade. Scotch whisky is exported to around 200 markets worldwide and supports over 40,000 jobs across the UK. Due to its large market and relatively high prices, Scotch whisky counterfeiting is common and costs the industry approximately 10 % in lost sales revenue per year. Most of the methods used to identify the authenticity of Scotch whiskies have focused on volatile organic congeners and analysis by gas chromatography. Other advanced analytical methods used include the determination of the stable isotopes ratio of carbon, hydrogen and oxygen. Alcoholic drinks also contain trace elements derived from the raw materials, production processes equipment, storage vessels and additives but compared with the determination of organic markers little application of trace elements to the identification of counterfeit whisky has been tested.
Benchtop total reflection x-ray fluorescence (TXRF) can be used for the analysis of alcoholic drinks but its use has not been reported within the Scotch whisky sector. The TXRF instrument we used (Bruker S2 PICOFOX) is portable and has detection limits that are 3-4 orders of magnitude improved compared with conventional XRF. The TXRF instrument in standard form is capable of simultaneously quantifying the concentration of many metals and non-metals, with the exception of so called “light elements”. Here we report on the elemental analysis of malt, grain and blended Scotch whiskies by TXRF for Cu, Zn, Fe, Ca, S, Cl, K, Mn, P, Rb and Br and the use of cold plasma ashing to reduce the background signals. The data, analysed by principal components, allowed discrimination between counterfeit and genuine whisky samples.
Jonathon Prus, Historical Metallurgy Society.
Hitherto the amount of iron produced in bloomery furnaces has been estimated from modern experimental archaeology and/or from relatively small samples of archaeological ores and slags. A fundamental problem has been the large variation between the analyses reported. Using the simplest of PXRF methods some larger samples from the Sussex Weald have been analysed. These have defeated a conjecture that there are major differences between sites that could be used to characterise and provenance of smelting residues and ores. Instead a striking similarity in mean values emerges. Large variance is confirmed but the samples exhibit unexpectedly regular distributions.
Tom Knott1, Michael J. Branney1, Marc Reichow1, Rob Coe2, David Finn2, Michael McCurry3
1 Department of Geology, University of Leicester, Leicester, UK.
2 Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, USA.
3 Department of Geosciences, Idaho State University, Pocatello, ID, USA,
Super-eruptions are amongst the most catastrophic events at the Earth's surface, with devastating regional environmental consequences and likely effects on global climate.
Its well-known that Yellowstone, USA, has erupted catastrophically in recent times, but perhaps less widely appreciated is that these were just the latest in a protracted history of numerous catastrophic super-eruptions that left a trail of devastation along the Snake River from Oregon (16 million years ago) to Yellowstone (most recent). New, previously undiscovered, records of super-eruptions are now being revealed in the volcanic record of the central Snake River Plain, Idaho, USA. Characterisation and widespread correlation of these immense deposits, from one mountain range to another, is hindered by the monotonous nature of the volcanic units, which has limited the use of conventional field-based techniques. Whole rock trace-element data generated on the University of Leicester’s PANalytical Axios Advanced X-Ray Fluorescence spectrometer has been invaluable in generating robust chemical fingerprinting of individual ash layers. Along with other techniques, (e.g., mineral chemistry and rock magnetism) each layer can be traced for 100’s of km, so that the size of each volcanic eruption can be determined. One such eruption is the newly defined Castleford Crossing eruption that effectively enamelled an area of >14,000 km2 in searing hot volcanic glass around 8.1 million years ago. The volume of this vast deposit is estimated to have exceeded 1,900 km3, and it is more than 1.3 km thick in the concealed caldera of the super-volcano. The size and magnitude of this eruption are as large if not larger than better known eruptions at Yellowstone, and it is just the first in a continually emerging record of additional super-eruption during a period of intense magmatic activity between 12 - 8 Ma.