Entity

Time filter

Source Type

Carrickfergus, United Kingdom

Stewart S.P.,Queens University of Belfast | Bell S.E.J.,Queens University of Belfast | Armstrong W.J.,Forensic Science Northern Ireland FSNI | Kee G.,Forensic Science Northern Ireland FSNI | Speers S.J.,Forensic Science Northern Ireland FSNI
Journal of Raman Spectroscopy | Year: 2012

Multilayer samples of white architectural paint potentially have very high evidential value in forensic casework, because the probability that two unrelated samples will have the same sequence of layers is extremely low. However, discrimination between the different layers using optical microscopy is often difficult or impossible. Here, lateral scanning Raman spectroscopy has been used to chemically map the cross-sections of multilayer white paint chips. It was found that the spectra did allow the different layers to be delineated on the basis of their spectral features. The boundaries between different layers were not as sharp as expected, with transitions occurring over length scales of > 20 μm, even with laser spot diameters < 4 μm. However, the blurring of the boundaries was not so large as to prevent recording and identification of spectra from each of the layers in the samples. This method clearly provides excellent discrimination between different multilayer white paint samples and can readily be incorporated into existing procedures for examination of paint transfer evidence. © 2011 Crown copyright. Source


Lee W.W.Y.,Queens University of Belfast | Silverson V.A.D.,Queens University of Belfast | Jones L.E.,Queens University of Belfast | Ho Y.C.,Forensic Science Center | And 5 more authors.
Chemical Communications | Year: 2015

A set of seized "legal high" samples and pure novel psychoactive substances have been examined by surface-enhanced Raman spectroscopy using polymer-stabilized Ag nanoparticle (Poly-SERS) films. The films both quenched fluorescence in bulk samples and allowed identification of μg quantities of drugs collected with wet swabs from contaminated surfaces. © 2016 The Royal Society of Chemistry. Source


Stewart S.P.,Queens University of Belfast | Bell S.E.J.,Queens University of Belfast | Fletcher N.C.,Queens University of Belfast | Bouazzaoui S.,Queens University of Belfast | And 3 more authors.
Analytica Chimica Acta | Year: 2012

Raman spectra of a representative range of β-ketophenethylamine (β-KP), the rapidly growing family of cathinone-related " legal high" recreational drugs, have been recorded. These spectra showed characteristic changes that were associated with the pattern of substitution on the aromatic rings, for example, the compounds carrying substituents at the 4- position could be distinguished from 3,4-methylenedioxy " ecstasy" derivatives. They also showed small but detectable changes with differences in substitution on the ethylamine substituent. These features allowed the β-KPs present in seized casework samples to be identified. The seized samples typically contained only small amounts of bulking agents, which meant that the band intensities of these components within averaged data were very small. In contrast, grid sampling normally gave at least some spectra which had a higher than average proportion of the bulking agent(s), which allowed them to also be identified. This study therefore demonstrates that Raman spectroscopy can be used both to provide a rapid, non-destructive technique for identification of this class of drugs in seized samples and to detect minor constituents, giving a composition profile which can be used for drugs intelligence work. © 2011. Source

Discover hidden collaborations