SIMS2015 Session AE-TuP: AE: Archeology/Environment/Forensics Poster Session
Time Period TuP Sessions | Topic AE Sessions | Time Periods | Topics | SIMS2015 Schedule
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AE-TuP-1 Investigation of Traditional Asian Lacquers using TOF-SIMS and other Analytical Techniques
Jihye Lee, Minjung Kim, Man-Ho Kim, Yeonhee Lee (Korea Institute of Science and Technology, Republic of Korea) In the Asian region, resinous sap obtained from lacquer tree is used as surface coating lacquer for wood, pottery and metallic substrates. Rhus vernicifera lacquer and Dendropanax morbifera lacquer are two representative types of Korean lacquers. The Rhus vernicifera sap is a water-in-oil type emulsion including water, urushiol and nitrogen-containing compounds. Especially, Rhus vernicifera lacquer is difficult to control because urushiol is allergenic compound. In lacquer process, color of sap is changed dark brown due to the polymerization by the action of laccase. Dendropanax morbifera is called Hwangchil in Korea.1 It has a brilliant golden yellow color and has been used for the high class people. There is no accumulated information about the lacquer components of Hwangchil because the sap of Hwangchil is hard to obtain and master craftsman become defunct. In recent years, natural lacquer, cashew nut shell liquid (CNSL), is widely used because of a cheap and excellent protective property.2 In this study, lacquer film from three kinds of sap and Asian remains were compared to identify the difference of their compositions. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) were used to provide useful information about the surface composition and the chemical structure of reference lacquer films that were prepared with Rhus vernicifera and Dendropanax morbifera saps. The bulk structure of lacquer films were investigated by Fourier transform infrared (FTIR) and Raman spectroscopy. Py-GC/MS was also used to identify specific organic compounds in the lacquer films and support TOF-SIMS and XPS results. |
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AE-TuP-2 Evaluation of ToF-SIMS with PCA to Identify Pigments in Artist’s Paints in Post War Art
Naoko Sano (National EPSRC XPS Users’ Service (NEXUS), UK); Steven Hinder, John F. Watts (University of Surrey, UK); Justin J. Perry, Brian W. Singer (Northumbria University, UK); Ian W. Fletcher, Peter J. Cumpson (National EPSRC XPS Users’ Service (NEXUS), UK) Scientific analysis is necessary when deciding upon the correct treatment method that should be used to conserve or restore artefacts including both old masterpieces and modern contemporary art works. The identification of the origin of materials in such artefacts is not straightforward. Modern paintings can be especially challenging because they incorporate synthetic organic pigments developed since the industrial revolution. These newer pigments are complex. Therefore, molecular information is key for identification, and surface analysis techniques could potentially be extremely valuable for studies of synthetic organic pigments and paints. Surface analysis may even assist in identifying the origin of such paints. To this end, we will address the growing demand from scientific and technological research to specify the local composition of a sample in terms of molecules rather than elements. The ability of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) to characterise pigments and paints is explored with valuable prior information about their chemical nature. This work demonstrates the potential of surface analysis techniques to contribute to a better understanding of modern paints for art conservators using a combination data-processing methods including Principal Component Analysis (PCA) and univariate analysis. In this work, pink and red paint flakes from a painting in Post-war art were validated against spectra from popular synthetic organic red quinacridone pigments [1]. The results obtained using ToF-SIMS and XPS in this study indicate that the flakes are of quinacridone origin rather than inorganic red pigments. This validation using our PCA model is likely to contribute effectively to the identification of the original materials in art works although further work will be needed to improve information on likely origin. Reference: [1] Sano, N., Cumpson, P.J., Cwiertnia, E., Perry, J.J. and Singer, B.W., Surf. Interface Anal., 46, 786 (2014) |
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AE-TuP-3 Total Ion Yields from U020a Monodisperse Particles Deposited on Graphite and Silicon Planchets with O-, O2-, and O2+ Primary Ion Beams
Nicholas Sharp, David Simons, John Fassett (National Institute of Standards and Technology) Large geometry secondary ion mass spectrometers (LG-SIMS) play an important role in nuclear forensics through their ability to identify accurately and precisely isotopic ratios of particles obtained from inspectors. As the particle mass can be on the order of sub-picograms it is important to maximize the sample utilization efficiency of U+ to make high quality measurements. The influence of primary ion beam species and polarity on U+ sample utilization efficiency has been previously investigated by Ranebo et al. (2008). To further that work we have analyzed the influence of sample substrate as well as primary ion beams on U+ sample utilization efficiency by analyzing mono-disperse U020a microspheres deposited onto graphite and silicon planchets. The particles were mapped using a scanning electron microscope with automated particle recognition and analysis and their coordinates were converted to the LG-SIMS coordinate system using fiducial marks. Results indicate higher U+ sample utilization efficiencies when sputtering with O- and O2- with graphite planchets, while O2+ gave slightly higher U+ sample utilization efficiencies with silicon substrates. Overall the negative primary ion beams produced higher U+ sample utilization efficiencies compared to positive primary ions. Additionally, during sputtering of uranium particles on silicon with O- and O2- a sudden drop in U+ signal intensity was observed which was not present during sputtering with O2+ or with particles on graphite. This drop in U+ signal intensity occurred simultaneously with an increase in UO+ and UO2+ signals, indicating a change in environment around the uranium particle that is unique to silicon compared to graphite. |
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AE-TuP-4 Minimizing the Fragmentation of Polycyclic Aromatic Hydrocarbons for Improved Source Apportionment
Joshua Wallace, Joseph Gardella, Jr. (University at Buffalo, The State University of New York) The ability to identify the source of atmospheric emissions is paramount to subsequently reducing particulate and aerosol pollution. Currently, source apportionment techniques utilize the quantitative profiles of a finite set of recalcitrant polycyclic aromatic hydrocarbons (PAHs) [1] followed by statistical attribution. These methods remain inherently limited by the exclusivity of the input values and the manner in which input values are handled [2]. Direct surface analysis of particulate matter (PM) by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) presents itself as an attractive alternative to targeted analysis by conventional solvent extraction and gas chromatography (GC) analysis due to direct surface analysis, minimal sample preparation and the ability to collect data on all species present. In order to maximize the statistical power of the source apportionment technique employed, it is imperative to preserve the molecular ion of the PAHs, thus minimizing primary ion-induced fragmentation is critical. A systematic analysis of primary ions and their respective parameters is performed to determine the primary ion which yields the optimal signal from a certified reference material for source apportionment. Primary ions examined in this study include Bi+, Bi3+, Bi3++, Cs+, C60+ and C60++. The optimal primary ion is then utilized to examine the PAHs present on standard reference diesel particulates to examine the resultant statistical attribution following principal component analysis (PCA) and the impact on source apportionment techniques discussed. [1] Liu, Y. et al. Atmospheric Environment, 107, 2015, 129-136. [2] Belis, C.A., et al., Atmospheric Environment, 69, 2013, 94-108. |
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AE-TuP-5 Characterization of Explosive Residues using MeV-SIMS
Lidija Matjacic, Julien Demarche (University of Surrey, UK); Nadia Abdul-Karim (University College London, UK); Vladimir Palitsin, John F. Watts, Steven Hinder, Roger Webb (University of Surrey, UK) Explosives are mostly organic substances that rapidly release a large amount of energy during decomposition, which is dissipated as blast waves, propulsion of debris, or the emission of thermal and ionizing radiation. Millions of tons of explosives are used every year for obtaining minerals and metals from the ground; in most cases, explosive detonations are used for coal mining. Also, explosives have been used extensively in both military and terrorist context. The misuse of explosives, which jeopardizes public safety, requires that appropriate detection and analysis measures are in place. These should be able to characterize the explosives and identify their source. While secondary ion mass spectrometry (SIMS) is a well-established surface characterization technique, recent years have seen the emergence of a new technique employing MeV heavy ions beams to produce secondary ions from an insulating sample surface: “MeV-SIMS”. Unlike keV primary ions, MeV ions can be extracted through a thin Si3N4 window and travel a few millimetres in air enabling imaging with a submicron resolution under ambient conditions. This avoids negative vacuum effects on sample, simplifies sample preparation and significantly decreases the total analysis time. In addition to MeV-SIMS analysis which provides information on chemical composition of sample, PIXE analysis can be performed simultaneously and give information on trace elemental composition. The combination of MeV-SIMS and PIXE potentially gives a good quality image at high spatial resolution. Samples of post blast material containing RDX, HMTD and PETN have been analyzed with ambient pressure MeV-SIMS using a 2MV Tandetron. Valuable information on the sample collection and storage has already been obtained. In this work we are aiming to identify the molecular signature of the explosive residues and their fragments in the spectra. For the spectra interpretation principal component analysis is performed to help specify and group different types of explosives. Additionally, results are also compared with keV-SIMS to demonstrate the sensitivity of the MeV technique. |
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AE-TuP-6 Reference Materials for SIMS Analysis of Uranium Isotopes in Micrometre-sized Particles for Nuclear Safeguards
T. Tanpraphan, Laure Sangely, O. Bildstein, E. Chinea-Cano, J. Poths, K.S. Vogt (International Atomic Energy Agency, Vienna International Center, Austria); A. Knott (International Atomic Energy Agency, Vienna International Center, Austria, Forschungszentrum Juelich, Germany); M. Duerr, R. Middendorp (Forschungszentrum Juelich, Germany) The international Atomic Energy Agency (IAEA)’s Network of Analytical Laboratories (NWAL), which includes the laboratories operated by the Office of Safeguards Analytical Services (SGAS) at Seibersdorf, analyse environmental samples that are collected by IAEA inspectors for the purpose of verifying the completeness of Member States’ declarations of their nuclear activities. Secondary Ion Mass Spectrometry (SIMS) has been successfully implemented since 1999 for uranium isotopic measurements (U-234, U-235, U-236, and U-238) at the scale of individual micrometer-sized particles. The goal is to reliably and accurately measure all nuclear process signatures captured by all uranium isotopes in the sample. Uranium reference materials in the form of micrometer-sized particles are routinely used for SIMS instrumental calibration. Particles for nuclear applications have been produced from certified reference materials by a variety of methods [1, 2]. One of the challenges associated with uranium particles analysis by SIMS, especially in light of recent improvements in measurement technology [3], is the assessment of varying particle characteristics (size, density, chemical form etc.) on the accuracy of analysis of environmental uranium particles. As part of this effort, the IAEA carried out SIMS measurements on a new generation of mono-dispersed reference uranium particles produced by the Forschungszentrum Juelich (Germany). A CAMECA IMS1280 instrument (Large-Geometry SIMS) was used to assess the reproducibility of useful ion yield for batches of particles synthesised with a specified number of uranium atoms. The results suggest that these new uranium particles are uniform and have similar characteristics (in terms of behaviour under O2+ bombardment) to the previous generations of particles, and to the larger particles from some environmental samples. The influence of the different methods used for transferring the particles from collecting media to analysis substrates was investigated. Subsequently, these uranium particles are used to study the influence of primary ion beam conditions (intensity, density, profile) upon uranium ion yield and instrumental mass fractionation. [1] Erdmann N. et al., Spectrochim. Acta; B55; 2000; 1565-1575; [2] Truyens J. et al., J. Environ. Radioact. ; 125 ; 2013 ; 50-55 ; [3] Ranebo Y. et al., J. Anal. At. Spectrom. ; 24 ;2009 ;277-287. |