Raman has been proven useful in the investigation of fibers, explosives, drugs, paints, inorganic fillers, and other materials in the field of forensics. Some advantages of Raman have been described below:
|Advantages of Raman in forensics
||Disadvantages of Raman in forensics
- Little or no sample preparation. Thus analysis is also possible without sample pre-treatment. This makes analysis of complex biological materials such as human tissue possible and allows the non-destructive analysis of bulk or microscopic materials in situ
- Convenient analysis of a solute in water. The weak Raman signal from water allows spectra to be easily collected from aqueous solutions or moist materials including illegal narcotics.
- The capability to measure through glass and plastic materials
- The ease to conduct remote sampling with fiber optic probes
- Raman techniques can attain high spatial resolutions which allow the analysis of discrete micron-sized particles. These are demonstrated by the determination of drug levels in individual cells and the analysis of gunshot residues.
- Cleaner spectra. Mid-IR often results in wider, overlapping bands that make interpretation difficult. With the same samples, Raman spectroscopy results in clean, narrow bands with little overtone or combination bands.
- The weakness of the Raman effect
- The potential for fluorescence interference. TIMEGATED® SOLVES THIS.
Forensics reseach examples with TimeGated®
Raman spectroscopy has proven to be useful in the detection of differences in the inks used in banknotes. However, the measurement with traditional CW Raman analysis results were not decisive to guarantee the authenticity of a specific banknote since similar Raman spectra were obtained for genuine and counterfeit banknotes (€10 and €20 from different European countries) in the current study by Guedes at al. 2013
Measuring genuine and fake banknotes with Timegated®:
Guedes, a., Algarra, M., Carmelo Prieto, a., Valentin, B., Hortelano, V., Neto, S., … Noronha, F. (2013). Raman microspectroscopy of genuine and fake Euro banknotes. Spectroscopy Letters, 46(8), 569–576.
Bartick, E. (2002). Forensic analysis by Raman spectroscopy: An emerging technology. In Proceedings of the 16th Meeting of the International Association of Forensic Sciences, Montpellier, France (pp. 45–50).