Discriminating Lipsticks

Using Raman Spectroscopy to Discriminate Lipsticks

Lipstick stains are sometimes encountered as physical evidence at crime scenes or from the clothing of a suspect. Conventional methods of analysis of lipsticks include visual comparisons, thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). These techniques are either subjective, destructive or a combination of both.

Constituents of lipstick include a mixture of castor oil, beeswax, carnauba wax and lanolin (typically making up 95% of the lipstick). The remainder consists of soluble and insoluble dyes, pigments and perfumes[1].

Here we present a brief study applying Raman spectroscopy to the discrimination of lipsticks.

Discriminating Explosives

Identification of explosives using the Foram-785 Raman Spectrometer

The worldwide threat from terror activities has increased steadily over the last 2 decades. In particular Improvised Explosive Devices (IED’s) provide a unique threat. The need for rapid identification of explosive residues both pre and post explosion as part of a Homeland Security Program is thus paramount.

Presumptive tests are the simplest examination carried out on explosive substances but they lack specificity. Field techniques such as Ion Mobility Spectroscopy (IMS) are expensive and can be prone to false positives. Whilst traditional Mass Spectrometry techniques, are expensive, and difficult to make field deployable.

One of the newer technologies to identify explosive residues is Raman spectroscopy.

The Foster & Freeman Foram-785  provides fast and non-destructive analysis of explosives and importantly is able to identify a specific explosive due to the “signature” spectrum that the explosive gives. It is able to get positive ID of particles < 3 microns in size.

Below are spectra of 3 high explosives, each showing a unique fingerprint of Raman peaks:

Figure 1 below shows a range of SERRS spectra of the samples used in this study.