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Analysis of lipsticks using Raman spectroscopy
P Gardner1, M F Bertino, R Weimer
1Department of Forensic Science, Virginia Commonwealth University, Box 843079, Richmond, VA 23284, USA.
Forensic Science International
|September 24, 2013
Summary
Raman spectroscopy effectively differentiated 95% of lipsticks using a 780 nm wavelength, overcoming fluorescence limitations. While useful for identification, specific manufacturer or category trends were not observed in the Raman peaks.
Area of Science:
- Analytical Chemistry
- Forensic Science
- Spectroscopy
Background:
- Lipstick analysis is crucial for forensic identification.
- Raman spectroscopy offers a non-destructive method for chemical analysis.
- Fluorescence can interfere with Raman spectral acquisition.
Purpose of the Study:
- To evaluate the efficacy of Raman spectroscopy for lipstick analysis.
- To compare the performance of different excitation wavelengths (532 nm and 780 nm).
- To assess the feasibility of in situ analysis of lipstick smears.
Main Methods:
- Acquisition and analysis of 80 lipstick samples.
- Utilized Raman spectroscopy with 532 nm and 780 nm excitation wavelengths.
- Investigated in situ analysis on various Raman-active substrates.
Main Results:
- The 780 nm excitation wavelength proved effective, overcoming fluorescence issues that limited the 532 nm line.
- Raman spectroscopy differentiated 95% of the analyzed lipsticks based on spectral peaks.
- No discernible trends were found to link specific Raman peaks to manufacturers or product categories.
- In situ analysis was feasible but occasionally hampered by background fluorescence and photodegradation.
Conclusions:
- Raman spectroscopy, particularly with a 780 nm laser, is a powerful tool for differentiating lipstick samples.
- The technique shows potential for forensic applications, though manufacturer-specific classification requires further research.
- In situ analysis capabilities are demonstrated, with limitations noted for specific environmental conditions.
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