Transmission infrared imaging microscopy and multivariate curve resolution applied to the forensic examination of automotive paints

Kwofie, Francis; Perera, Undugodage Don Nuwan; Allen, M. D.; Lavine, Barry K.

doi:10.1016/j.talanta.2018.02.025

Cited by 13 publications

(7 citation statements)

References 14 publications

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“…also used chemometrics to differentiate color and manufacturer but used IR spectroscopy instead. 78 Ferreira et al used hyperspectral imaging visible/near-infrared (HSI-VIS/NIR) spectroscopy and chemometrics for discriminating between different colors of car paint. 79 Most colors were able to be 100% differentiated, but black car paint gave much lower classification power.…”

Section: ■ Paintmentioning

confidence: 99%

Toward Locard’s Exchange Principle: Recent Developments in Forensic Trace Evidence Analysis

et al. 2018

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Section: ■ Paintmentioning

confidence: 99%

Toward Locard’s Exchange Principle: Recent Developments in Forensic Trace Evidence Analysis

et al. 2018

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“…The benefit of not collecting a mixed IR spectrum is higher quality matches when performing a search of PDQ or any other forensic automotive paint databases against an OEM paint sample. In a previous study, 10 we demonstrated that an IR spectral image of a cross‐sectioned paint chip can be obtained in less than 1 h. The amount of time required for a scan is dependent on the map area of the sample selected.…”

Section: Introductionmentioning

confidence: 98%

“…Ideally, the epoxy should present little or no spectral interference. In a previous study, Lavine and coworkers 10 cast automotive paint chips in 30 min and blue light epoxy followed by cross sectioning each paint chip using a microtome. As the epoxy cured, however, it infiltrated specific layers in some automotive paint chips contaminating their IR spectra, which in turn prevented accurate spectral library matching of these chips by PDQ.…”

Section: Introductionmentioning

confidence: 99%

Application of infrared microscopy and alternating least squares to the forensic analysis of automotive paint chips

Kwofie

Perera

Allen

et al. 2020

Journal of Chemometrics

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To collect infrared (IR) absorbance spectra from an automotive paint chip with an IR imaging microscope, it is a common practice to cast the paint chip in epoxy and then cross section it using a microtome to reveal the individual layers of paint. Ideally, the epoxy should present little or no spectral interference. However, the epoxy can infiltrate individual layers of the paint chip as it cures contaminating the IR spectra of the layers and impairing the accuracy of a search of each of these layers against an automotive paint library. In this study, we have demonstrated that automotive paint chips can be successfully cross sectioned without the use of embedding media. Sample preparation is easier, and more importantly, interfering peaks in the spectra due to the epoxy are eliminated. To demonstrate the advantages of this approach for sample preparation, IR image maps of four automotive paint chips that were not cast in epoxy prior to cross sectioning were collected. After each IR image was unfolded using an oblique transit to traverse the image, the spectra of the individual paint layers comprising the line map were reconstructed by alternating least squares. Comparing each recovered IR spectrum against a spectral library, we show that high quality spectral matches were obtained for spectra from the same line/model of the vehicle from which the paint sample originated. When the same paint chips were cast in epoxy prior to cross sectioning, high quality spectral matches could not always be obtained.

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“…using FTIR imaging. 6,17,27 The purpose of this paper is to demonstrate that along the cross-sections of automotive paint samples individual profiles of the distributions of elements as well as chemical compounds can be obtained by LIBS and Raman spectroscopy, respectively. Both methods have the advantage that they require minimal sample preparation.…”

Section: Introductionmentioning

confidence: 99%

Cross-section measurements of multilayer automotive paint samples using combined Raman spectroscopy and LIBS

Merk

Werncke

2022

Analyst

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Transmission infrared imaging microscopy and multivariate curve resolution applied to the forensic examination of automotive paints

Cited by 13 publications

References 14 publications

Toward Locard’s Exchange Principle: Recent Developments in Forensic Trace Evidence Analysis

Toward Locard’s Exchange Principle: Recent Developments in Forensic Trace Evidence Analysis

Application of infrared microscopy and alternating least squares to the forensic analysis of automotive paint chips

Cross-section measurements of multilayer automotive paint samples using combined Raman spectroscopy and LIBS

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