Portable Raman Spectroscopy as a Functional Tool in Homeland Security Izake, 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 – dm 2 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 excitation 2 Capable of rapid detection, acquisition times of 1 minutes when analyzing amphetamine street samples 3 Ultra trace amounts of illicit drugs (5 – 20 µm in size) found under nail varnish in a non-destructive manner in under three minutes 4
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 metres 5
Ahura First Defender Currently in use by emergency response teams 6 Has been used to assist the FBI to identify hazardous materials 7 Results of the analysis of the “First Defender” instrument have been used in court to assist in a conviction 9
Ahura Tru. Narc 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 Analyzer 8 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
References 1. 2. 3. 4. 5. 6. 7. 8. 9. Izake, E. , Forensic and homeland security applications of modern portable Raman spectroscopy. Forensic Science International. (2010), vol 9, pp. 1 – 8 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 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 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 S. K. Sharma, New trends in telescopic remote Raman spectroscopic instrumentation, Spectrochim. Acta Part A 68 (5) (2007) 1008 – 1022 City of Albany, NY. Department of Fire, Emergency Services and Code Enforcement Accomplishments for 2009. Monmouth County Health Department Hazardous Materials Response/UST Units 2009 Annual Report Information obtained from brochure provided by contact with Rigaku Raman Technologies (www. rigakuraman. com) Rains, S. (2011, May 7), Convict Guilty of Courthouse Hoax. Lawton Constitution (http: //www. swoknews. com/main. asp? Section. ID=11&Sub. Section. ID=98&Article. ID= 34618)
Ahura Tru. Scan in use
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