Introduction of the system of complex SEM analyses-automated analysis of soil phases & RS in practice of expert service of PČR

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00007064%3AK01__%2F19%3AN0000037" target="_blank" >RIV/00007064:K01__/19:N0000037 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Introduction of the system of complex SEM analyses-automated analysis of soil phases & RS in practice of expert service of PČR

Original language description

Conference "Conference 2019 - project SYSTEM OF COMPLEX SEM ANALYSES", article in conference proceedings: "Introduction of the system of complex SEM analyses-automated analysis of soil phases & RS in practice of expert service of PČR", p. 21-22 abstract: Techniques of electron microscopy are widely applied in a forensic field, both for an initial screening and a final expert assessment. The set of materials that are delivered to a forensic lab is very extensive, practically any material produced by human and nature activities relating to the case that is examined can be encountered (ranging from the fragment of an ancient vessel, data records, documents, to high-tech semiconduc-tors). Therefore, materials of organic origin, plants and animal fragments, etc., are investigated as well. Automated mineralogical analyses are a great asset of the system for the analysis of mineral phases, particularly soils. Classification of minerals into individual classes is carried out on the basis of BSE signal and chemical composition. The obtained quantitative data are subsequently processed through statistical methods. Other identification options for differentiation of mineral phases hardly distinguishable by different analyses are provided by cathode lumines-cence, mainly colour one and an accurate quantitative measurement of their spectral characteristics using microspectrofotometer. Until recently, the analysis of the organic phase has brought big problems in multicomponent particles and composites by applying SEM. This ques-tion has been in principle unsolvable for e.g. analysis of postblast resi-dues, when retrieval of the particles of 10 µm in heavily contaminated sample by techniques that would allow the analysis of its organic compo-nent is not feasible. One of the very interesting options appears to be the Raman spectrometry technique, which is nowadays available as a supplement to SEM EDX. Newly available is the device that is fully confocal, SEM keeps full func-tionality and scan range, very high resolution (for green laser resolution 360nm FWHD; 430nm Rayleigh), it is fitted with high quality objective lens, allows mapping through Raman spectrometry in a volume 250µm x 250µm x 250µm by piezo driven scanner (capacitive feedback linearized) and ob-taining high quality white light image (250µm x 250µm) immediately in the SEM chamber. This technique is currently undergoing intensive testing and it seems that the method could significantly help to solve problems with the analysis of organic phases in electron microscopy, not only in the case of post-blast residues and explosives. The application of new techniques significantly extends possibilities of classic microscopic procedures in a forensic field and allows acquisition of needed quantitative data in the forensic analysis of pedological phases, discrimination of mineral phases or the option of analysis of the organic phase directly in the SEM chamber.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

50902 - Social sciences, interdisciplinary

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů