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Holm JD, Mansfield E. Transmission electron imaging and diffraction of asbestos fibers in a scanning electron microscope. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:4570-4581. [PMID: 38912607 DOI: 10.1039/d4ay00555d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Test protocols for airborne clearance of asbestos abatement sites define the collection, imaging and quantification of asbestos with transmission electron microscopy (TEM). Since those protocols were developed 35 years ago, scanning electron microscope (SEM) capabilities have significantly improved and expanded, with improvements in image spatial resolution, elemental analysis, and transmission electron diffraction capabilities. This contribution demonstrates transmission electron imaging and diffraction using NIST Asbestos Standard Reference Materials and a conventional SEM to provide comparable identification and quantification capabilities in the SEM as the current regulatory methods based on TEM techniques. In particular, we demonstrate that the 0.53 nm layer line spacing that is characteristic of asbestos can be quantified using different detection methods, and that other identifying diffraction signatures of chrysotile are readily obtained. The results demonstrate a viable alternative to the current TEM-based methods for asbestos identification and classification.
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Affiliation(s)
- Jason D Holm
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, USA.
| | - Elisabeth Mansfield
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, USA.
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Bandli BR, McNamee BD. Mineralogical and dimensional characterization of EMPs destined for biological experimentation. ENVIRONMENTAL RESEARCH 2023; 230:114528. [PMID: 36965794 DOI: 10.1016/j.envres.2022.114528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/05/2022] [Indexed: 05/30/2023]
Abstract
Mineral specimens and mineral reference materials should be understood to be mixtures of various mineral species and the properties of each individual species will likely represent a range of quantifiable values and qualitative characteristics. The use of incompletely characterized mineral specimens may introduce significant uncontrolled variables in any experiment. Any mineral characterization should include an understanding of the bulk properties of the specimen as well as microanalytical and crystallographic characterization of individual mineral phases. This characterization should comprise a range of length scales to accommodate naked-eye level observations up to electron microscopic observations and analyses. Large spatial scale observations are useful to describe the physical properties of the material and understand the scale of inhomogeneities that may be present in a mineral sample. Microanalysis provides critical compositional and crystallographic information for mineral identification. It is critical to recognize where gaps might exist in the data produced during the characterization of a material and if those gaps are critical to evaluating the effect those minerals might have on the result of a given experiment. Likewise, it is critical to understand the interplay of various minerals that might be present in a sample other than the specific mineral of interest. The accessory minerals that are present, even if only trace amounts, could have a major impact and need to be isolated, or their impact accounted for in the interpretation of results. Dimensional characterization of particulate produced from a mineral specimen is important, but not as simple a task as it might appear. Dimensional data can be produced through any of several microscopic techniques, each with specific limitations and potential to be biased due to sample preparation technique. This understanding of the full composition of a mineral specimen cannot be obtained through rudimentary examination and it cannot be taken for granted that it has been performed by the supplier of the specimen.
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Affiliation(s)
- Bryan R Bandli
- RJ Lee Group Inc., 800 Presque Isle Dr, Pittsburgh, PA 15239, USA.
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Ervik TK, Benker N, Weinbruch S, Skogstad A, Thomassen Y, Ellingsen DG, Berlinger B. Phase identification of individual crystalline particles by combining EDX and EBSD: application to workplace aerosols. Anal Bioanal Chem 2018; 410:2711-2721. [PMID: 29492620 DOI: 10.1007/s00216-018-0949-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/31/2018] [Accepted: 02/06/2018] [Indexed: 11/25/2022]
Abstract
This paper discusses the combined use of electron backscatter diffraction (EBSD) and energy dispersive X-ray microanalysis (EDX) to identify unknown phases in particulate matter from different workplace aerosols. Particles of α-silicon carbide (α-SiC), manganese oxide (MnO) and α-quartz (α-SiO2) were used to test the method. Phase identification of spherical manganese oxide particles from ferromanganese production, with diameter less than 200 nm, was unambiguous, and phases of both MnO and Mn3O4 were identified in the same agglomerate. The same phases were identified by selected area electron diffraction (SAED) in transmission electron microscopy (TEM). The method was also used to identify the phases of different SiC fibres, and both β-SiC and α-SiC fibres were found. Our results clearly demonstrate that EBSD combined with EDX can be successfully applied to the characterisation of workplace aerosols. Graphical abstract Secondary electron image of an agglomerate of manganese oxide particles collected at a ferromanganese smelter (a). EDX spectrum of the particle highlighted by an arrow (b). Indexed patterns after dynamic background subtraction from three particles shown with numbers in a
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Affiliation(s)
- Torunn Kringlen Ervik
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 8149 DEP, 0033, Oslo, Norway.
| | - Nathalie Benker
- Institute of Applied Geosciences, Technical University Darmstadt, Schnittspahnstr. 9, 64287, Darmstadt, Germany
| | - Stephan Weinbruch
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 8149 DEP, 0033, Oslo, Norway
- Institute of Applied Geosciences, Technical University Darmstadt, Schnittspahnstr. 9, 64287, Darmstadt, Germany
| | - Asbjørn Skogstad
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 8149 DEP, 0033, Oslo, Norway
| | - Yngvar Thomassen
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 8149 DEP, 0033, Oslo, Norway
| | - Dag G Ellingsen
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 8149 DEP, 0033, Oslo, Norway
| | - Balázs Berlinger
- Department of Chemical and Biological Work Environment, National Institute of Occupational Health, P.O.Box 8149 DEP, 0033, Oslo, Norway
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Abbasi M, Kim DI, Guim HU, Hosseini M, Danesh-Manesh H, Abbasi M. Application of Transmitted Kikuchi Diffraction in Studying Nano-oxide and Ultrafine Metallic Grains. ACS NANO 2015; 9:10991-11002. [PMID: 26482120 DOI: 10.1021/acsnano.5b04296] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Transmitted Kikuchi diffraction (TKD) is an emerging SEM-based technique that enables investigation of highly refined grain structures. It offers higher spatial resolution by utilizing conventional electron backscattered diffraction equipment on electron-transparent samples. A successful attempt has been made to reveal nano-oxide grain structures as well as ultrafine severely deformed metallic grains. The effect of electron beam current was studied. Higher beam currents enhance pattern contrast and intensity. Lower detector exposure times could be employed to accelerate the acquisition time and minimize drift and carbon contamination. However, higher beam currents increase the electron interaction volume and compromise the spatial resolution. Lastly, TKD results were compared to orientation mapping results in TEM (ASTAR). Results indicate that a combination of TKD and EDS is a capable tool to characterize nano-oxide grains such as Al2O3 and Cr2O3 with similar crystal structures.
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Affiliation(s)
- Majid Abbasi
- High Temperature Energy Materials Research Center, Korea Institute of Science and Technology , Seoul 02792, Republic of Korea
| | - Dong-Ik Kim
- High Temperature Energy Materials Research Center, Korea Institute of Science and Technology , Seoul 02792, Republic of Korea
| | - Hwan-Uk Guim
- Korea Basic Science Institute , Daejeon 34133, Republic of Korea
| | - Morteza Hosseini
- Department of Materials Science and Engineering, Shiraz University , Shiraz, Iran
| | - Habib Danesh-Manesh
- Department of Materials Science and Engineering, Shiraz University , Shiraz, Iran
| | - Mehrdad Abbasi
- Department of Mining and Metallurgy, Amirkabir University of Technology , Tehran, Iran
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