X‐ray Diffraction and Rietveld Refinement in Deferrified Clays for Forensic Science |
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| Authors: | Luis V. Prandel Ph.D. Vander de F. Melo Ph.D. André M. Brinatti Ph.D. Sérgio da C. Saab Ph.D. Fábio A. S. Salvador Ph.D. |
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| Affiliation: | 1. Soil Science Department, Federal University of Paraná, Curitiba (PR), Brazil;2. Soil Physics and Environmental Sciences, Department of Physics, State University of Ponta Grossa, Ponta Grossa (PR), Brazil;3. Technical and Scientific Sector, Federal Police Department, Curitiba (PR), Brazil |
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| Abstract: | Soil vestiges might provide information about a crime scene. The Rietveld method with X‐ray diffraction data (RM‐XRD) is a nondestructive technique that makes it possible to characterize minerals present in the soils. Soil clays from the metropolitan region of Curitiba (Brazil) were submitted to DCB treatment and analyzed using XRD with CuKα radiation in the step‐scan mode (0.02° 2θ/5 s). The GSAS+EXPGUI software was used for RM refinement. The RM‐XRD results, together with the principal component analysis (PCA) (52.6% total variance), showed the kaolinite predominance in most analyzed samples and the highest quartz contents in “site 1.” Higher anatase, and gibbsite and muscovite contents influenced discrimination, mainly in “site 3” and “site 1,” respectively. These results were enough to discriminate clays of four sites and two horizons using a reduced amount of sample showing that the technique can be applied to the investigation into soil vestiges. |
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| Keywords: | forensic science rietveld method multivariate analysis dithionite– citrate– bicarbonate kaolinite gibbsite crystallite size |
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