1. Portable Raman Spectroscopy as a Functional Tool in Homeland Security
Why are we concerned
First response detection of hazardous substances in emergency services (police, fire department) and in screening of samples (airport and border 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

2. 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
There are many tools which have been developed for the identification of unknown substances, such as drugs, chemical or biological warfare agents, explosive, and toxic agents. When developing these tools there is a goal for sensitivity, selectivity, and speed, especially when looking at the use of these identification tools in the fields of forensics and law enforcement.
Conventional techniques some of which have been covered in class in the past, include
Gas chromatography/ mass spec
High performance liquid chromatography/ mass spec
And Teraherz radiation spectroscopy
Note that these techniques are time consuming, destructive, require treatment of sample, bulky instrumentation
These techniques carry limitations, however. These limitations include
That the operator must….
Instuments must….
And these techniques are not portable. They would require the movement of complex insturments, or you must take the sample to the machine.

3. 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
Raman spectroscopy is a spectroscopic technique which has been developed into a portable tool which can be used without the operator or the instrument coming into contact with the sample. This is an important advantage in cases where the sample is an unknown, potentially hazardous material, or where the sample can not be easily moved.

4. 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
The theory behind Raman spec uses monochromatic light applied to the intended sample.
Most of the light is either absorbed or passes through the sample unchanged, but a small fraction is elastically scattered with the same frequency as the incident light ( approximately 0.1%) and an even smaller fraction is scattered inelastically. Approximately one photon in 10^6 or 10^7. This is Raman scattering
The Raman fraction is scattered with either lower or higher frequency than the incident light. Lower frequencies are called stokes scattering and higher frequencies are anti stokes scattering.
The difference in the returning scattered light corresponds to an energy shift in the molecules of the target sample, probing the vibrational modes of the molecules. These vibrational modes give an energy shift which provides a unique chemical fingerprint.

5. Run through picture:
The incident ligh (blue) hits the target molecules, which causes them to vibrate.
they produce elastically scattered light, which is the same wavelenght as the incident light and is filtered out, and inelastically scattered light, raman, which a different wavelenght than the incident light and is allowed through the filter.
the raman scattering is deflected off a diffraction grating, which disperses the light onto a detertor which then allows a spectrum to be generated, which is unique to the target molecule.
Note the chromatogram output
Similar to IR (that we should all be familiar with) in that it gives a chromatogram that can be referenced against a library of chromatograms to determine what the samples is

6. 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

7. Raman spectroscopy has become fully portable
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
Detection can…
Raman figerprint is independent of excitation wavelenght… this allows for the use of any laser to cause exitation. This is an important advantage because the raman signal can have low intensity. By adjusting the kind of laser used it is possible to intesify the signal. by using excitation wavelenghts in the Near infrafred region or the deep UV regions, fluorescence interference can be avoided. Excitation with a UV laser gives a higher sensitivity to the spectrum and shortens the acquisition time and it avoids interference of solar radiation, therefore…
Detection can be done…
Raman…

8. 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
Showing examples of what this technology can do
2: NIR laser excitation was used to discriminate the spectra of illicit substances; even in the presence of adulterants and dilutants
3: quick acquisition times where shown in a study on [amphetamines with unknown adulterants
4: spectra obtained with no sample preparation, and was completely non-destructive

9. 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
The gating of the detector is coordinated with the laser pulse to restrict data collection to the time period where the raman-scattered photons are expected to reach the detector
This means that samples can ne identified from distances
This also limits possible UV and fluorescent interference as those sources will come back to the detector at different rates than the raman scattering

10. 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
The first defender is a portable raman made by ahura
It is already in use within the security industry
6: example found of it being used by the city of albany, ny
7: tinton falls police department used device to identify a package of unknown white powder sent by mail as cocaine
9: used to succesfully identify an unknown white powder sent to the district attorney in Comach County, OK. Leading to a guilty plea in court

11. Ahura TruNarc
- ViVideo from 1:50 to 3:00
Note the ease of use of the instrument
“anyone can use it”
Speeds the process of drug identification within police departments
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

12. 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
Another example of handheld Raman spectroscopy
Emphasize the simplicity of use
Requires no maintenace or calibration

13. 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

14. References
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 Annual Report
Information obtained from brochure provided by contact with Rigaku Raman Technologies (
Rains, S. (2011, May 7), Convict Guilty of Courthouse Hoax. Lawton Constitution (

15. Ahura TruScan in use Play from 0:30 and beyond
This video will emphasize the ease of use of portable raman devices
Will show examples of raman spec working through barriers to analyze for samples
Demonstrates the quick analysis of the instrument
Reduced workload in laboratories