Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry

Authors

Seongshin Gwak, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Chemistry

First Advisor's Name

José R. Almirall

First Advisor's Committee Title

Major Professor

Second Advisor's Name

Anthony P. DeCaprio

Second Advisor's Committee Title

Committee member

Third Advisor's Name

Fenfei Leng

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Wenzhi Li

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Bruce R. McCord

Fifth Advisor's Committee Title

Committee member

Keywords

New Psychoactive Substances; Ion Mobility Spectrometry; Mass Spectrometry

Date of Defense

9-17-2015

Abstract

In the new era of drug abuse, the proliferation of new psychoactive substances (NPS), commonly referred to as designer drugs or legal highs, has been a global concern. These substances are produced to circumvent current legislation for controlled substances with minor modifications in their chemical structure. Although many efforts have been made previously, the characterization of such substances are still challenging because of (1) the continual emergence of newly identified substances, (2) the lack of a universal screening test for NPS that are structurally similar to each other, and (3) the complex and time-consuming chromatographic techniques currently used. Therefore, it is necessary to develop novel analytical methods that can be readily adapted by forensic laboratories to overcome these challenges.

In this dissertation, various analytical techniques have been evaluated for qualitative analysis of these emerging NPS. For rapid screening purposes, a commercial ion mobility spectrometry with a ⁶³Ni ion source (⁶³Ni-IMS) and also direct analysis in real time coupled to a quadrupole time-of-flight mass spectrometer (DART-QTOF-MS) were investigated first. The results showed that rapid detection by ⁶³Ni-IMS and identification by DART-QTOF-MS can be achieved with sub-nanogram detection capability and high speed total analysis time less than two minutes. In recent developments of gas chromatography mass spectrometry (GC-MS), gas chromatography (GC) has been coupled to state-of-the-art mass spectrometers, including triple quadrupole (MS/MS) and quadrupole time-of-flight (QTOF). It was revealed that the application of GC-MS/MS and GC-QTOF facilitates the unambiguous identification of emerging NPS with a chemical ionization (CI) source. In addition, constitutional isomers of NPS were differentiated with the capabilities of product ion scan and multiple reaction monitoring (MRM) modes. Finally, the coupling of IMS with a mass spectrometer (IMS-MS) was investigated as an alternative confirmatory technique. With the development of an optimal solvent system in the electrospray ionization (ESI) process, the rapid analysis and identification of synthetic cathinone was successfully achieved less than five minutes. As a proof-of-concept, seized drugs samples provided by a local forensic laboratory were analyzed using these developed methods by various analytical techniques. The results from these seized samples are also presented in this evaluation.

Identifier

FIDC000157

Recommended Citation

Gwak, Seongshin, "Comprehensive Analysis of Emerging New Psychoactive Substances by Ion Mobility Spectrometry and Mass Spectrometry" (2015). FIU Electronic Theses and Dissertations. 2291.
https://digitalcommons.fiu.edu/etd/2291