evaluation of the odor compounds sensed by explosive-detecting canines_erica lotspeich

Graduate School ETD Form 9 (Revised 12/07) PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Entitled For the degree of Is approved by the final examining committee: Chair To the best of my knowledge and as understood by the student in the Research Integrity and Copyright Disclaimer (Graduate School Form 20), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy on Integrity in Research” and the use of copyrighted material. Approved by Major Professor(s): ____________________________________ ____________________________________ Approved by: Head of the Graduate Program Date Erica H. Lotspeich Evaluation of the Odor Compounds Sensed by Explosive-Detecting Canines Master of Science John V. Goodpaster Jay Siegel Sapna Deo John V. Goodpaster John V. Goodpaster July 13, 2010 Graduate School Form 20 (Revised 1/10) PURDUE UNIVERSITY GRADUATE SCHOOL Research Integrity and Copyright Disclaimer Title of Thesis/Dissertation: For the degree of ________________________________________________________________ I certify that in the preparation of this thesis, I have observed the provisions of Purdue University Teaching, Research, and Outreach Policy on Research Misconduct (VIII.3.1), October 1, 2008.* Further, I certify that this work is free of plagiarism and all materials appearing in this thesis/dissertation have been properly quoted and attributed. I certify that all copyrighted material incorporated into this thesis/dissertation is in compliance with the United States’ copyright law and that I have received written permission from the copyright owners for my use of their work, which is beyond the scope of the law. I agree to indemnify and save harmless Purdue University from any and all claims that may be asserted or that may arise from any copyright violation. ______________________________________ Printed Name and Signature of Candidate ______________________________________ Date (month/day/year) *Located at http://www.purdue.edu/policies/pages/teach_res_outreach/viii_3_1.html Evaluation of the Odor Compounds Sensed by Explosive-Detecting Canines Master of Science Erica Lotspeich 07/13/2010 EVALUATION OF THE ODOR COMPOUNDS SENSED BY EXPLOSIVE-DETECTING CANINES A Thesis Submitted to the Faculty of Purdue University by Erica H. Lotspeich In Partial Fulfillment of the Requirements for the Degree of Master of Science August 2010 Purdue University Indianapolis, Indiana ii First and foremost I would like to dedicate this to God for His guidance and blessings. I would like to dedicate this to my husband, Chris, for his support and tolerance through my long educational journey. I would also like to thank my daughter, Bobbi, for always giving me hugs and kisses. Lastly, I would like to dedicate this to my parents for always believing in and praying for me. iii ACKNOWLEDGMENTS I would like to thank John Goodpaster, PhD, my advisor and graduate mentor, for his guidance and support. I would like to thank Rick Strobel with the ATF for his guidance. I am very grateful to the Technical Scientific Working Group and the Department of Defense for their financial support. Finally, I would like to thank Jay Siegel, PhD and my defense committee for their dedicated time. iv TABLE OF CONTENTS Page LIST OF TABLES vi LIST OF FIGURES vii ABSTRACT ix CHAPTER 1. INTRODUCTION 1 1.1. Canine Detection 1 1.2. Odor Availability 3 1.3. Explosive Odor Compounds 4 CHAPTER 2. CHARACTERIZATION OF THE CONCENTRATION AND DIFFUSION OF EXPLOSIVE VAPORS IN CONTAINERS DESIGNED FOR CANINE ODOR RECOGNITION TESTING 7 2.1. Introduction 7 2.1.1 Theory 10 2.2. Materials and Methods 14 2.3. Results and Discussion 18 2.3.1. Headspace Measurements 18 2.3.2. Mass Loss Measurements 21 2.4. Conclusion 27 CHAPTER 3. DIFFUSION OF EXPLOSIVE VAPOR IN A CONTAINER USED FOR CANINE TRAINING 29 3.1. Introduction 29 3.2. Materials and Methods 31 3.2.1. Data Analysis 32 3.2.1.1 Diffusion Limited and Steady-State Systems 32 3.2.1.2 Preliminary Canine Tests 32 3.3. Results and Discussion 33 3.3.1. Fick's Second Law of Diffusion 33 3.3.2. The Equilibration of Diffusion-Limited and Steady-State Systems 36 3.3.3. Preliminary Canine Test 40 3.4. Conclusion 42 CHAPTER 4. EXPLOSIVE ODOR COMPOUNDS 44 4.1. Introduction 44 4.2. Materials and Methods 47 4.2.1. SPME and Headspace GC/MS 47 v Page 4.3. Results and Discussion 48 4.3.1. SPME and Headspace GC/MS 48 4.4. Conclusion 54 CHAPTER 5. RECOMMENDATIONS 55 5.3. Modifications 55 5.2. Future Directions 58 LIST OF REFERENCES 62 APPENDIX . 66 vi LIST OF TABLES Table Page Table 2.1 Calculated miniumum saturation points of nitroalkanes 12 Table 2.2 Chemical properties of nitroalkanes 15 Table 3.1 Preliminary canine test results 41 Table 4.1 Characteristics of high explosives 45 vii LIST OF FIGURES Figure Page Figure 2.1 Geometry of National Odor Recognition Test 8 Figure 2.2 Schematic of Type 2 behavior 11 Figure 2.3 Schematic of the integrated version of Fick's Law 14 Figure 2.4 Effect of Vapor Pressure and Sample Amount 19 Figure 2.5 Effect of Container Size and Sample Amount 20 Figure 2.6 Effect of Temperature and Sample Amount 21 Figure 2.7 Effect of Confinement on Flux 23 Figure 2.8 Effect of Sample Amount on Flux 24 Figure 2.9 Effect of Molecular Weight on Flux 25 Figure 2.10 Unimolar Diffusion 26 Figure 3.1 Fick's Second Law of Diffusion 35 Figure 3.2 Effect of Vapor Pressure and Confinement on Equilibration Rate in an Open Quart-Sized Can 37 Figure 3.3 Effect of Vapor Pressure and Confinement on Equilibration Rate in a Closed Quart-Sized Can 38 Figure 3.4 Effect of Sample Amount in a Quart-Sized Can 39 Figure 3.5 Confirmation of Preliminary Canine Test 41 Figure 3.6 Confirmation of Preliminary Canine Test 42 Figure 4.1 Extraction Procedure for SPME 46 Figure 4.2 Desorption Procedure for SPME 46 Figure 4.3 Comparison of SPME Fiber Coatings 49 Figure 4.4 Confirmation of Odor Compounds 50 Figure 4.5 Confirmation of Odor Compounds 51 Figure 4.6 Confirmation of Odor Compounds 52 Figure 4.7 Confirmation of Odor Compounds 53 Appendix Figure Figure A.1 66 Figure A.2 67 Figure A.3 68 Figure A.4 69 Figure A.5 70 Figure A.6 71 Figure A.7 72 Figure A.8 73 viii Appendix Figure Page Figure A.9 74 Figure A.10 75 Figure A.11 76 Figure A.12 77 Figure A.13 78 Figure A.14 79 [...]... and the results were compared to the Ideal Gas Law and Fick’s Laws of Diffusion Overall, these findings x provide increased awareness about availability of explosive odors and the factors that affect their generation; thus, improving the training of canines Another area of uncertainty deals with the complexity of the odor generated by the explosive, as the headspace may consist of multiple chemical compounds. .. between the liquid and vapor phases In a mixture, the partial pressure of each gas is independent of the other gases present in the system [8, 9] Flux is defined as the amount of material that is transferred through a given opening over time [9, 10] Other factors that may affect the amount of vapor present is the molecule’s rate of diffusion as well as the attraction of the molecule to the surface of a... saturated and only a portion of the liquid vaporizes (𝑉𝑉𝑥𝑥 ) Two phases then remain in the container, creating a headspace above the liquid In this case, the moles of gas in the vapor phase (𝑛𝑛 𝑔𝑔 ) are equivalent to the moles of liquid that vaporizes (𝑛𝑛 𝑥𝑥 ) The volume of the headspace (𝑉𝑉ℎ ) is the volume of the container (𝑉𝑉𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 𝑐𝑐 𝑐𝑐 𝑐𝑐 𝑐𝑐𝑐𝑐 ) less the volume of the liquid that remains after... headspace of a pure substance is determined by the vapor pressure of the compound (𝑃𝑃° ) and the temperature (T) of the system As a result, the minimum volumes of liquid nitroalkanes required to saturate various containers at room temperature can be calculated by the Ideal Gas Law, the molecular weight of the sample, and the literature value for the vapor pressure of the explosive sample as shown in Table... has a dendrite that extends to the surface of the nasal lining and projecting from each of the dendrites are 20-30 cilia When an odor molecule is inhaled it comes into contact with the cilia of the nasal mucosal lining and sensory transduction occurs Sensory transduction is the binding of the odorant molecule to an odorant receptor The odorant receptors are comprised of three α-helical barrels that... barrier to the free movement and predictability of the odor [2] 5 1.3 Explosive Odor Compounds In a post September 11, 2001 world the need to detect explosives has become of great interest to our country The development of a dependable and effective mode of detection is in great demand by the government The most effective mode of explosive detection are sniffing dogs because they have the ability... increases in the sample amount did not add to the headspace concentration This trend was seen with analysis of the other nitroalkanes as well The effect of temperature on an explosive’s vapor pressure was also studied The determination of vapor pressure at different temperatures is calculated by the ClausiusClapyeron equation The temperature of the system increases the vapor pressure of the compound... was the rate of evaporation� � 𝑑𝑑𝑑𝑑 𝑑𝑑𝑑𝑑 The rate of evaporation, the calculated diffusion coefficient for the three nitroalkanes, as listed in Table 2.1, the equilibrium concentration which was based upon the vapor pressure of the nitroalkanes at room temperature and the thickness of the sniffer tin lid which was 0.5 mm were used to predict the unimolar diffusion The calculated mole fractions of nitroalkanes... chemical properties of an explosive and other factors influence the amount of explosive vapor that can be sampled by a canine The chemical properties of an explosive that may affect canine recognition include the molecule’s vapor pressure, diffusion coefficient and the resultant flux of the molecule from a container The molecules total vapor pressure is the partial pressure of the substance when equilibrium... questions regarding the training and testing of canines This has led to difficulties in comparing the sensitivity of canines to one another as well as to analytical instrumentation Several chemical properties of an explosive as well as other factors influence the amount of explosive vapor A common misconception is that the amount of explosive itself is the main contributor to the amount of odor available . Compounds Sensed by Explosive-Detecting Canines Master of Science Erica Lotspeich 07/13/2010 EVALUATION OF THE ODOR COMPOUNDS SENSED BY EXPLOSIVE-DETECTING CANINES A Thesis Submitted. of canines. Another area of uncertainty deals with the complexity of the odor generated by the explosive, as the headspace may consist of multiple chemical compounds due to the extent of. ABSTRACT Lotspeich, Erica, H. M.S., Purdue University, August, 2010. Evaluation of the Odor Compounds Sensed by Explosive-Detecting Canines. Major Professor: John V. Goodpaster. Trained canines