Study of the Transport of Odorants from Illicit Substances Using Direct Analysis in Real Time Mass Spectrometry

Authors

Torki A. Zughaibi, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Chemistry

First Advisor's Name

Kenneth G. Furton

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Michelle Peace

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Yong Cai

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Alexander Mebel

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Stewart D'Alessio

Fifth Advisor's Committee Title

Committee member

Keywords

Direct analysis in real time, forensic science, canine, volatile organic compounds, odor, controlled odor mimic permeation systems

Date of Defense

6-29-2017

Abstract

Canines have been employed in matters of law enforcement because of their keen sense of smell. Presently, law enforcement officials are utilizing trained canines in routine traffic stops to assess if the vehicle contains any illicit substances. Many believe that this is an infringement on an individual’s fourth amendment rights, which has garnered the attention of both the media and the courts. Many questions have been raised with respect to canines alerting to locations where illicit substances were no longer present. Thus, the purpose of this dissertation research is to evaluate the manner in which active odorants transport and persist onto various substrates.

Direct Analysis in Real Time (DART) coupled to an accurate-mass time-of-flight (AccuTOF™) mass spectrometer was used to rapidly analyze the volatile organic compounds (VOC’s) from a variety of narcotic and explosive substances. The DART ion source is a soft ionization technique used in ambient conditions to sample liquids, solids or gases in real time. Thermal desorption of the VOC’s could thus be conducted in seconds. The present study found that the VOC’s from illicit substances transport from one location to another, in a short amount of time, through a process known as advection, which may contribute to canines producing unconfirmed alerts during their training and certifications. Three of the four odorants used in this study produced positive results, with the exception being 2-ethyl-1-hexanol, as it was not detected at any time when held at distances between 0.5 and 3 meters.

In addition, the amount of time needed for an active odorant to contaminate an object in its immediate vicinity was explored and the results were determined to be inconclusive. Although they were observed following longer exposure times, it was still deemed to be inconclusive since it was still possible for these odorants to be present, albeit not in detectable amounts, at lower exposure times.

Controlled odor mimic permeating systems (COMPS), patented technology by IFRI were tested to determine the possibility of cross-contamination between the training aids, and the results conclude that there was not any evidence of cross-contamination observed during any of the trials.

Identifier

FIDC001940

Recommended Citation

Zughaibi, Torki A., "Study of the Transport of Odorants from Illicit Substances Using Direct Analysis in Real Time Mass Spectrometry" (2017). FIU Electronic Theses and Dissertations. 3398.
https://digitalcommons.fiu.edu/etd/3398