Applications of Fourier Transform Raman Spectroscopy in Forensic Science

Kuptsov, Albert H.

doi:10.1520/jfs13604j

Cited by 69 publications

(37 citation statements)

References 12 publications

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“…Moreover, Raman spectra generally extend well below 600 cm 1 , a region where many inorganic pigments and extenders have important vibrational bands. 18 Because of the complementary nature of both techniques and because of the importance of IR spectroscopy in forensic science, it is worthwhile to examine the possible contribution of Raman spectroscopy to this research, although until now little work has been done on the Raman spectroscopic study of automotive paints. 16,17 These studies focussed on red organic pigments 16 and inorganic pigments 17 in the topcoat, while our explorative research gives an overview of the possibilities of Raman spectroscopy in car paint analysis by examining the pigments, binders and extenders in all paint layers.…”

Section: Introductionmentioning

confidence: 99%

Forensic analysis of automotive paints by Raman spectroscopy

Gelder

Vandenabeele

Govaert

et al. 2005

J. Raman Spectrosc.

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In this work, the possible contribution of Raman spectroscopy in forensic science is evaluated, more specifically for the analysis of automotive paint samples. Spectra from paint flakes as well as from cross sections were examined, in order to identify not only the pigments but also binders and extenders in all paint layers. Moreover, the possibility of distinguishing paint samples from different cars was evaluated to assess the use of vibrational spectroscopic techniques in the investigation of a hit-and-run accident.The presence of rutile and extenders, such as calcite and barium sulphate, could be demonstrated by their characteristic Raman bands. However, the identification of the binder by Raman spectroscopy was hampered: only with additional information from IR analysis could most of the bands in the spectrum be assigned to molecular vibrations of the binders. In contrast, organic pigments, having very distinctive and well-resolved characteristic bands, could easily be identified by comparing the spectra from the basecoat of the sample with spectra from a reference database. Because of these characteristic bands, the basecoat seems to provide the best spectra to distinguish paint samples. Moreover, some paints can also be distinguished by the absence or presence of the bands from calcium carbonate and barium sulphate in the primer surfacer. When recording spectra from paint flakes, Raman bands from the spectra of the clearcoat as well as from the basecoat are obtained.

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Section: Introductionmentioning

confidence: 99%

Forensic analysis of automotive paints by Raman spectroscopy

Gelder

Vandenabeele

Govaert

et al. 2005

J. Raman Spectrosc.

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“…There are only a few data in the literature on the subject of using this technique in the study of fragments of paint coatings. 45,46 It is interesting that some paint components may have vibrational modes that produce no IR absorption bands, but may produce Raman bands.…”

Section: Raman Microspectroscopymentioning

confidence: 99%

Microspectrophotometry in Forensic Science

Ziȩba‐Palus¹

2000

Encyclopedia of Analytical Chemistry

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Infrared microspectrophotometry is a combination of two techniques – optical microscopy and infrared (IR) spectrometry – which supply specific information about the composition and structure of a given material. The equipment used is a Fourier transform infrared (FTIR) spectrometer connected on line with an optical microscope. The microscope allows observation of a sample in white light at relatively high magnification; this allows its morphology and microstructure to be established, and facilitates selection of the area which will subsequently be subjected to IR spectrometric analysis. The microscope also permits use of polarized light in investigations. The spectrometer enables analysis of a sample with a chosen measuring technique – transmission or reflection – with the aim of determining the chemical composition of the sample. It also supplies information about its microstructure and orientation. This method is particularly useful in the analysis of trace amounts of various substances secured as material evidence in court cases, and in analysis of the homogeneity of the sample, identification of inclusions and contaminants on the surface, and detection of structural defects. A specific advantage of this method is its ability to unambiguously photograph and record marked and measured areas of the sample and minimize the process of preparing the sample for analysis. Furthermore, IR microspectrophotometry gives the rare opportunity of studying small crystals or areas in the oriented materials by using polarized IR radiation, both by the transmission and the reflection technique. Its fundamental drawback is that the physical nature of the microsample may influence the precision of the photometric measurements and cause distortion of the spectra (artefacts) obtained. Furthermore, because only a small area is studied the heterogeneity of the sample and the amount of contaminants may significantly influence the results of spectrometric measurements. Microspectrophotometry in the ultraviolet/visible (UV/VIS) range is a combination of photometric measuring techniques and optical microscopy. It allows comparison of the color of very small samples of various materials, such as single fibers, tiny amounts of paint, traces of ink or ball‐point pen ink on a forged document in an objective way, independently of the sharpness and quality of the observers's vision. It yields immediate information about spectral differences existing between two samples of similar color, which are indistinguishable by use of the optical microscope. Additionally, using appropriate software to analyze the results of microspectrometric measurements, it enables precise measurement of a color, and – applying the theory of colors – gives a color a defined numerical value; this facilitates communication between experts working with this method. The equipment consists of an optical microscope with a spectrometer for analysis in the visible and ultraviolet range, connected to a microcomputer via an analog‐to‐digital converter.

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“…2,3,4 It has proven successful in such applications as narcotic identification, 5,6 fibre identification, 7 paints/pigments analysis, 8 gunshot residue analysis, 9 gemstone identification, 10 and finally explosive identification, 11 and detection. 12,13,14 Hazardous materials such as asbestos have also been successfully analysed using Raman spectroscopy.…”

Section: Introductionmentioning

confidence: 99%