STANDOFF VIBRATIONAL SPECTROSCOPY DETECTION OF EXPLOSIVES AND OTHER CHEMICAL THREATS

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OTHER CHEMICAL THREATS SAMUEL P. HERNANDE

1 ALERT-DHS-COE CENTER FOR CHEMICAL SENSORS DEVELOPMENT CHEMICAL IMAGING CENTER STANDOFF VIBRATIONAL SPECTROSCOPY DETECTION OF EXPLOSIVES AND OTHER CHEMICAL THREATS SAMUEL P. HERNANDEZ-RIVERA Ph.D. UNIVERSITY OF PUERTO RICO MAYAGUEZ DEPARTMENT OF CHEMISTRY OCT/19/2010 RICC

2 OUTLINE Standoff Vibrational Spectroscopy Detection FT-IR Active Experiments FTIR Passive Experiments IR Active Raman CW Ongoing/future work Raman CW Experiments Pulsed Laser Experiments Passive Pulsed Ongoing/future work ALERT Publications OCT/19/2010 RICC

Aluminum Sheet MIR SOURCE EM27 OPEN PATH

4 cm -1 resolution Surface loadings: 50-400

3 MIR SOURCE- ACTIVE MODE EXPERIMENTS EXPERIMENTAL SET-UP: BRUKER OPTICS EM27 Aluminum Sheet MIR SOURCE EM27 OPEN PATH FTIR SPECTROMETER Target: High Explosive TNT Experimental conditions Ten spectra were taken for each sample, at 20 scans and 4 cm -1 resolution Surface loadings: µg/cm 2 The analyzed distances were : 4, 8, 12, 16, 20, 25 and 30 m. Experiments were carried out at room temperature (25 C). OCT/19/2010 RICC

4 Absorbance DETECTION OF TNT AT DIFFERENT SURFACE CONCENTRATIONS NO 2 symmetric stretch C-C breathing µg/cm 2 µg/cm 2 µg/cm 2 µg/cm 2 µg/cm 2 C-H bending Absorbance DETECTION OF TNT AT DIFFERENT DISTANCES m 8m 12m 16m 20m 25m 30m Wavenumber / cm Fixed distance: 16 m. Signals decreased with surface concentration. NO 2 (1650 cm -1 ) band masked by water vapor signals 700 OCT/19/2010 RICC Wavenumber/cm Fixed surface loading 400 µ/cm 2 At distances larger than 25 m, signals are not clearly observed: Chemometrics: Great help!!

EM27 OPEN PATH FTIR SPECTROMETER Absorbance OCT/19/2010 5 RICC-11 2010 0.04 0.035 0.03 0.

5 PASSIVE MODE STANDOFF DETECTION OF TNT USING THERMAL EXCITATION EXPERIMENTAL SETUP Radiation Emission How to heat the aluminum sheet? EM27 OPEN PATH FTIR SPECTROMETER Absorbance OCT/19/ RICC C 26 C 27 C 28 C 29 C 30 C C-C C-H Wavenumber/cm -1 Distance: 16 m Surface concentration: 400 µg/cm 2 720

6 TNT DETECTION AT DIFFERENT T Surface concentration: 400 µg/cm Bands: 793, 1170 and 1085 cm -1 TNT 200 µg/cm 2-16m y = 1.32E-03x E-02x E-01 R² = 9.99E-01 Absorbance m-31 C 8m-32 C 16m-32 C 4m-28 C Area y = 7.96E-04x E-02x E-01 R² = 9.95E-01 y = 3.39E-04x E-02x E-01 R² = 9.99E-01 Band 793 cm-1 Band 1087cm-1 Band 1171cm Wavenumber/cm Temperature / C Characteristic signatures of TNT are well defined; band intensities increase with T When TNT is heated to T higher than ambient temperature, more signals stand out. OCT/19/2010 RICC

7 QUANTIFICATION: PLS PLS parameters: No preprocessing, spectra were mean centered Predicted Concentration (ug/cm 2 ) TNT PLS 25 o C True Concentration / ug/cm 2 Distance : 8 m True Conc. Predicted Concentration / µg/cm 2 Distance : 16 m TNT PLS - 32 o C True Conc True Concentration / µg/cm 2 TEMPERTURE R 2 RMSECV TEMPERTURE R 2 RMSECV Using thermal excitation, good correlations were found even at different temperatures. OCT/19/2010 RICC

8 Absorbance DISCRIMINATION PETN + BENZOIC ACID A homemade mixture: 50%:50% ONGOING WORK petn 36oC Benz. Acid 36oC petn+benz. Acid 36oC 1000 Wavenumber/cm PULSED LASER HEATING 700 Absorbance TNT 200 ug/cm2 Al 27 C 8 m TNT 200 ug/cm2 Al 20 C 6 m Wavenumbers / cm -1 Red Trace: Standoff distance ~ 6 m Development of algorithms for 1. Sample exposed to pulsed laser shots 2. Room T ~ 20 C; sample T ~ C removal of water vapor signals: Blue Trace: Standoff distance ~ 8 m Max Diem, NU; Miguel Velez, UPRM 1. sample heated by tungsten lamp heating 2. Room T ~ 25 C; sample T ~ 27 C OCT/19/2010 RICC

from QCL to Target Surface Contamination IR Light Collected Back Block

9 NEXT: LASERSCAN QUANTUM CASCADE LASER ANALYZER INFRARED ABSORPTION SPECTROSCOPY SYSTEM FOR DETECTION OF SURFACE CONTAMINATION Visible Laser Pointer IR Light from QCL to Target Surface Contamination IR Light Collected Back Block Engineering LaserScan detection of surface trace and bulk material OCT/19/2010 RICC

STANDOFF RAMAN SYSTEM Pulsed Laser System Focal Plane A A Input Slit Ch.

1 Concave Mirror CCD Convex Grating Design details of the Remote Raman Detection

reflective telescope signal collector; (4) variable focus secondary mirror; (5)

10 STANDOFF RAMAN SYSTEM Pulsed Laser System Focal Plane A A Input Slit Ch.2 Input Slit Ch.1 Concave Mirror CCD Convex Grating Design details of the Remote Raman Detection System: (1) laser source; (2) sample; (3) 5 in. diam. reflective telescope signal collector; (4) variable focus secondary mirror; (5) standoff distance; (6) fiber optic coupling; (7) details of optical coupling; (8) spectrograph. Movable optical elements are represented by double arrows. OCT/19/2010 RICC

11 PROXIMITY CW LASER RAMAN DETECTION OF CWA-SIMULANTS / TICs 2-BAET x 6 x 6 x 6 (a) Intensity / a.u. 2-CEES DMMP nm nm 488 nm Intensity / a.u (b) (c) Raman Shift / cm -1 Remote Raman spectra of CWAS using excitation lines of 488.0, and nm at 6.6 m target-collector distance, 1 W laser power and 10 s integration Raman Shift / cm -1 Remote Raman spectra of aromatic TICs: (a) chlorobenzene; (b) toluene; (c) benzene. Target-collector distance: 6.6 m; CW laser source: nm 1 W; 10 s integration. OCT/19/2010 RICC

STEP 1: CHANGED TO PULSED LASERS Spectra Physics-Newport: INDI and LAB PRO 290 Able to detect at standoff distances > 30 m; no lights interference Normalized Intensity 10 9 8 7 6 5 4 3 1000 pulses,

f e d c b a (a) 1 pulse (c) 50 pulses (e) 500 pulses (b) 10 pulses (d) 100 pulses (f) 1000 pulses 2 1 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 Raman Shift / cm -1 Spectra of cyclohexane

12 STEP 1: CHANGED TO PULSED LASERS Spectra Physics-Newport: INDI and LAB PRO 290 Able to detect at standoff distances > 30 m; no lights interference Normalized Intensity pulses, 532 nm on cyclohexane 60 m 91 m 141 m Intensity / a.u. f e d c b a (a) 1 pulse (c) 50 pulses (e) 500 pulses (b) 10 pulses (d) 100 pulses (f) 1000 pulses Raman Shift / cm -1 Spectra of cyclohexane using pulsed laser at standoff distances of 60, 90 and 141 m, measured with 1000 laser shots in gated mode. Laser: 532 nm, 200 mj/pulse (max), 10 Hz; gate width 400 ns Raman Shift / cm- 1 Remote Raman spectra of DMMP using a 532 nm pulsed excitation source at a distance of 35 m, measured with various laser shots in gated mode. Laser: 532 nm, 200 mj/pulse, 10 Hz. OCT/19/2010 RICC

STEP 2: EFFECT OF OPTIMIZED IMAGING SPECTROGRAPH Headwall Photonics Raman Explorer Acetone, CH region 6 m SO Headwall vs. Andor Peak heights ~ 21.3 : 1.

13 STEP 2: EFFECT OF OPTIMIZED IMAGING SPECTROGRAPH Headwall Photonics Raman Explorer Acetone, CH region 6 m SO Headwall vs. Andor Peak heights ~ 21.3 : Headwall 100 pulses 6 m Headwall 100 pulses 6 m Andor 100 pulses 6 m Andor 1000 pulses 6 m Intesity Andor 100 pulses 6 m Intesity / counts Raman shift / cm -1 Raman shift / cm OCT/19/ RICC

RANGE DEPENDENCE OF TNT DETECTION Counts (Log scale) 1500000 d: 8 m, r: 1.7 d: 16 m, r: 0.30 d: 20m, r: 0.26 d: 30 m, r: 0.20 d: 45 m, r: 0.14 d: 60 m, r: 0.

14 RANGE DEPENDENCE OF TNT DETECTION Counts (Log scale) d: 8 m, r: 1.7 d: 16 m, r: 0.30 d: 20m, r: 0.26 d: 30 m, r: 0.20 d: 45 m, r: 0.14 d: 60 m, r: 0.05 # pulses: 1000; t: 100 s Counts (Log scale) y = 1E+07e x R² = Raman shift / cm d / m OCT/19/2010 RICC

RANGE AN: > 140 m OTHER HEMs 3.0 2.8 1000 pulses, 532 nm cyclohexane (CH) Ammonium Nitrate (AN) at 141 m 1500000 ANFO AN PETN Normalized Intensity 2.5 2.3 2.0 1.8 1.5 141 m CH 141 m AN Counts (Log scale) 150000 RDX 1.

15 RANGE AN: > 140 m OTHER HEMs pulses, 532 nm cyclohexane (CH) Ammonium Nitrate (AN) at 141 m ANFO AN PETN Normalized Intensity m CH 141 m AN Counts (Log scale) RDX Raman Shift / cm -1 Cyclohexane and ammonium nitrate at 141 m d = 20 m, 1000 pulses Raman shift / cm -1 Other high explosives at d = 20 m OCT/19/2010 RICC

16 EFFECT OF SAMPLE AND LASER SIZE r = Sample Area Laser Spot Area Sample Area A Laser Spot Area = πab 4 Sample B Laser Spot Area Variable area OCT/19/2010 RICC

17 SAMPLE SIZE AND LASER SPOT Counts (Log scale) d: 16 m # pulses: 1000 t: 100 s sample size: 25 mm sample size: 12 mm r: r: r: r: r: Counts sample size: 8 mm sample size: 4 mm y = -4E+07x 2 + 2E+07x R² = sample size: 2 mm Raman shift / cm r OCT/19/2010 RICC

18 STEP 3: UPGRADE COLLECTOR RC OPTICAL SYSTEMS 10 RITCHEY- CHRÉTIEN IMAGING TELESCOPE OCT/19/2010 RICC

19 FUTURE WORK: STANDOFF DETECTION OF BIOAEROSOLS BIOAEROSOL DETECTION BY REMOTE RAMAN SPECTROSCOPY Aerolized sample NR SERS Spectrograph Lens Filter Lens Detector Mirror Metallic Nanoparticle suspension solution Computer Laser OCT/19/2010 RICC Filter 19

20 ALERT PUBLICATIONS 1. Ramirez, M.L., Pacheco, L.C., Barreto M.A. and Hernández-Rivera, S.P., Enhanced Raman Detection using Spray-On Nanoparticles/Remote Sensed Raman Spectroscopy, in Nanoscience and Nanotechnology for Chemical and Biological Defense, R. Nagarajan, Walter Zukas, T. Alan Hatton, Stephen Lee, Eds., ACS Symposium Series # 1016, Ch. 10, pp , Oxford University Press, New York, NY, Pacheco-Londoño, L.C., Ortiz-Rivera, W., Primera-Pedrozo, O.M. and Hernandez-Rivera, S.P., "Vibrational Spectroscopy Standoff Detection of Explosives, 2009, Anal. Bioanal. Chem., 395: DOI /s y. 3. Ramírez, M.L., Ortiz, W., Pacheco-Londoño, L.C. and Hernández-Rivera, S.P., Remote Detection of Hazardous Liquids Concealed in Glass and Plastic Containers, 2010, IEEE J. Sensors, 10 (3): doi: /JSEN Hernández-Rivera, S.P., Pacheco-Londoño, L.C., Ortiz-Rivera, W., Castro-Suarez, J.R., O.M. Primera-Pedrozo and Félix-Rivera, H., Remote Raman and Infrared Spectroscopy Detection of High Explosives, in Explosive Materials: Classification, Composition and Properties, Janssen,T.J., ed., Chemical Engineering Methods and Technology Series, Nova Science Publishers, Inc. Hauppauge, NY, fourth quarter 2010, ISBN: Ortiz, W., Pacheco-Londoño, L.C. and Hernández-Rivera, S.P., Standoff Raman Spectroscopy System for Detection of Chemical Warfare Agents Simulants and Toxic Industrial Compounds, Sens Imaging., Castro-Suarez J., Pacheco-Londoño, L.C., Hernández-Rivera, S.P Open Path FTIR Standoff Detection of High Explosives on Surfaces, App. Spectrosc. Submitted for publication, OCT/19/2010 RICC

21 ACKNOWLEDGMENTS "This material is based upon work supported by the U.S. Department of Homeland Security under Award Number 2008-ST-061- ED0001. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security." OCT/19/2010 RICC

22 THANKS OCT/19/2010 RICC

R. L. Aggarwal, L. W. Farrar, S. Di Cecca, and T. H. Jeys. MIT Lincoln Laboratory, Lexington, MA

Raman spectra and cross sections of ammonia, chlorine, hydrogen sulfide, phosgene, and sulfur dioxide toxic gases in the fingerprint region 400 1400 cm 1 R. L. Aggarwal, L. W. Farrar, S. Di Cecca, and