Portable Raman Spectroscopy as a Functional Tool in Homeland SecurityIzake, E. , Forensic and homeland security applications of modern portable Raman spectroscopy. Forensic Science International. (2010), vol 9, pp. 1 – 8
Kassandra Luening and Neil Rybak
Conventional Techniques
GC/MS HPLC/MS THZ (Terahertz radiation spectroscopy)
Limitations Operator must come into contact with potentially
hazardous samples Instruments must be disposed of or decontaminated after
contact with hazardous materials These techniques are not portable. Require the
movement of complex instruments
Portable Raman Instruments
Allows for the portability of Raman spectroscopy
High volumes of samples can be scanned, without the operator coming into contact with the sample, and the units are now fully portable
Chemistry of Raman Spectroscopy
Monochromatic light applied to sample Incident light is scattered
Rayleigh (elastic) and Raman (inelastic) Rayleigh scatter is filtered out The returned scattered light is a
different wavelength This difference corresponds to an
energy shift which provides a unique chemical fingerprint
Advantages of Raman Spectroscopy
Provides molecular fingerprints of each analyte, providing the possibility of highly selective determinations
Applicable to any optically accessible sample; organic, inorganic, or biological
Solid, liquid, gaseous, transparent and non-transparent samples can be measured
Aqueous solutions present no special technical problems
Sample scanning is non-invasive
Detection can be of sample sizes from 1 µm – dm2 and distances from millimetres up to several metres
Raman fingerprint is independent of excitation wavelength, allowing for the use of any laser for excitation
Detection can be done day and night without the presence of background signals due to ambient light interference
Raman spectroscopy has become fully portable
Examples of Portable Raman in Use
Has been used to identify illicit drugs using NIR laser excitation2
Capable of rapid detection, acquisition times of 1 minutes when analyzing amphetamine street samples3
Ultra trace amounts of illicit drugs (5 – 20 µm in size) found under nail varnish in a non-destructive manner in under three minutes4
Stand-off Raman detection of hazardous substances Constructing a gated
detector system can restrict the laser pulse of the light source
Data collected at the time the laser is expected to arrival at the sample
Allows for sample detection from distances up to 100 metres5
Ahura First Defender
Currently in use by emergency response teams6
Has been used to assist the FBI to identify hazardous materials7
Results of the analysis of the “First Defender” instrument have been used in court to assist in a conviction9
Ahura TruNarc
The ease of use of the instrument and the library of samples “potentially eliminates the need for a chemist to testify” Simple non-expert use of the instrument
Rigaku Firstguard Handeld Analyzer8
No sample prep needed
Operated like a point and shoot camera
Delivers results in seconds with no chance of human error
User can either build their own database or use supplied library
Conclusions Portable Raman has been shown to be more
effective than conventional methods in the detection of drugs and other hazardous samples No contact of sample with analyst or
instrument High throughput capability Can be used in close proximity of sample or at
distances Can analyze organic, inorganic and biological
samples through containers, in both light and dark environments
New portable instrumentation is user friendly allowing non expert users to easily identify samples
References1. Izake, E. , Forensic and homeland security applications of modern portable
Raman spectroscopy. Forensic Science International. (2010), vol 9, pp. 1 – 8
2. S.E.J. Bell, D.T. Burns, A.C. Dennnis, L.J. Matchett, J.S. Speers, Composition and profiling of seized ecstasy tablets by Raman spectroscopy, Analyst 125 (10) (2000) 541 – 544
3. E. Katainen, M. Elomaa, M. Laakkonen, E. Sippola, P. Niemela, K. Janne Suhonen, Jarvinen, Quantification of the amphetamine content in seized street samples by Raman Spectroscopy, J. Forensic Sci. 52 (1) (2007) 88 – 90
4. E. Ali, H. Edwards, M. Hargreaves, I. Scowen, Raman spectroscopic investigation of cocaine hydrochloride on human nail in a forensic context, Anal. Bioanal. Chem. 390 (4) (2008) 1159 – 1166
5. S.K. Sharma, New trends in telescopic remote Raman spectroscopic instrumentation, Spectrochim. Acta Part A 68 (5) (2007) 1008 – 1022
6. City of Albany, NY. Department of Fire, Emergency Services and Code Enforcement Accomplishments for 2009.
7. Monmouth County Health Department Hazardous Materials Response/UST Units 2009 Annual Report
8. Information obtained from brochure provided by contact with Rigaku Raman Technologies (www.rigakuraman.com)
9. Rains, S. (2011, May 7), Convict Guilty of Courthouse Hoax. Lawton Constitution (http://www.swoknews.com/main.asp?SectionID=11&SubSectionID=98&ArticleID=34618)
Ahura TruScan in use
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