Raman analysis of multilayer automotive paints in forensic science: measurement variability and depth profile1. (14th May 2014)

• Record Type: Journal Article
• Authors: Lambert, Danny; Muehlethaler, Cyril; Gueissaz, Line; Massonnet, Geneviève; Ropret, Polonca; Madariaga, Juan Manuel
• Is Part Of: Journal of Raman spectroscopy. Volume 45:Number 11/12(2014)
• Page Start: 1285
• Page End: 1292
• Publication Date: 2014-05-14
• Subjects: Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.4490
• Languages: English
• ISSNs: 0377-0486

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The aim of this work is to study the influence of several analytical parameters on the variability of Raman spectra of paint samples. In the present study, microtome thin section and direct (no preparation) analysis are considered as sample preparation. In order to evaluate their influence on the measures, an experimental design such as 'fractional full factorial' with seven factors (including the sampling process) is applied, for a total of 32 experiments representing 160 measures. Once the influence of sample preparation highlighted, a depth profile of a paint sample is carried out by changing the focusing plane in order to measure the colored layer under a clearcoat. This is undertaken in order to avoid sample preparation such a microtome sectioning. Finally, chemometric treatments such as principal component analysis are applied to the resulting spectra. The findings of this study indicate the importance of sample preparation, or more specifically, the surface roughness, on the variability of the measurements on a same sample. Moreover, the depth profile experiment highlights the influence of the refractive index of the upper layer (clearcoat) when measuring through a transparent layer. Copyright © 2014 John Wiley &amp; Sons, Ltd.</p> </abstract>