Application of Raman spectroscopy for the differentiation of lipstick traces

Abstract

This study demonstrates that Raman spectroscopy is a valuable tool for discriminating between lipstick samples under a range of forensically relevant situations. Trace amounts of lipstick smears deposited on textile fibres, cigarette butts and paper tissues were analysed.Differentiation of lipstick smears could be achieved with little or no interference from the underlying medium. Lipstick smears on glass slides, cigarette butts and tissues could also be analysed and identified in situ through evidence bags. Using a range of excitation frequencies (473, 633 and 784 nm) was effective in overcoming problems with fluorescent lipstick samples. The majority of the spectra of deposited lipstick samples remained unchanged over a period of up to two years. In some of the aged lipstick spectra, the (C=C) band at 1655 cm -1 and the (=CH) band at 3011 cm -1 were found to decrease in intensity and disappear over time.The use of chemometrics for the characterisation of large numbers of lipstick spectra was explored. Thirty spectra each from ten different lipsticks were analysed by Principal Components Analysis (PCA) and classified using the K-Nearest Neighbours (KNN) classifier. Up to 98.7% correct classification was achieved. Spectra from trace amounts of lipstick smears deposited on fibres were also analysed and classified using the same technique. 100% correct classification of these samples was achieved.

Forensic Methods of Non-Destructive Testing: Development Prospects

“…Другими, достаточно новыми методами для российских судебных экспертов, являются рамановская спектроскопия (спектроскопия комбинационного рассеяния), предложенная американскими криминалистами [5], и метод резерфордовского рассеяния [6]. Неразрушающий анализ структуры и элементного состава объекта в приповерхностной зоне является основным профилем исследований для указанных методов.…”

“…Наличие таких идентификационных баз упростит саму процедуру исследования криминалистами, которая станет до-ступной даже для тех, кто не имеет физического или химического образования. Подтверждением этого являются исследования авторов работы [5].…”

“…Известен ряд примеров результативного применения в экспертной практике одного из современных методов неразрушающего контроля, рамановской спектроскопии (КР спектроскопии). Так, ученые из Университета Кента [5] наглядно продемонстрировали возможность идентификации типа и марки декоративной косметики, на примере губной помады с помощью спектроскопии комбинационного рассеяния. Следы губной помады на стеклянной посуде, окурках и текстиле были успешно проанализированы без удаления прозрачной пластиковой упаковки для улик.…”

A multitechnique approach for discrimination and identification of lipsticks for forensic purposes

“…The largest number of articles on the discriminant analyses of lipsticks describes the use of Raman spectroscopy (RS) [5][6][7][8][9]. In these publications [5][6][7][8][9], RS is presented as a simple and quick technique that does not require any sample preparation. Spectra can be recorded in situ on the various surfaces on which the tested lipstick traces were applied.…”

Lipsticks Elemental Analysis by Energy Dispersive X-Ray Used as Criminal Evidence

“…The combined SEM/EDX techniqueis indispensable for fast, nondestructive, physicochemical analysis of trace evidence and solid objects of anysize.The SEM/EDX isnot ideal for quantitative analysis of elements presentas traces. The ability of the SEM/EDX to detect an element below aminimum detection limit (MDL) (0.1-0.3% w/w) (17) . Experimental Part: Sampling: Four lipstick samples were selected for one brand with different colors (Lipstick-03,Lipstick-23, Lipstick-29 and Lipstick-51) as well as two different colors for the so-called magic lipstick(Luxe orang and Luxe yellow).…”