DOI

https://doi.org/10.25772/A3DW-WD42

Defense Date

2020

Document Type

Thesis

Degree Name

Master of Science

Department

Forensic Science

First Advisor

Dr. Michelle Peace

Second Advisor

Mr. Justin Poklis

Third Advisor

Dr. Rima Franklin

Fourth Advisor

Dr. Frances Scott

Abstract

Monitoring current illicit drug trends and consumption rates of pharmaceuticals using a non-invasive collection technique is needed to address the present drug use and the growing drug epidemic. Reliance on self-reporting drug use surveys is not always a practical measure of illicit drug use. Wastewater analysis has been used globally as a targeted method for monitoring the consumption of specific illicit drugs. Current existing analytical techniques for wastewater analysis focus on the use of targeted liquid chromatography-mass spectrometry (LC-MS) based techniques. Few gas chromatography (GC) procedures exist for wastewater analysis, and those that do concentrate their methods on a single class of drugs operating their mass spectrometer (MS) in selective ion monitoring (SIM) mode. This study aims to develop an untargeted, underivatized, full scan gas chromatography-mass spectrometry (GC/MS) method for the analysis of wastewater. Solid phase extraction (SPE) was performed with UCT mixed mode, 15 mL Clean Screen DAU columns with 500 mg sorbent to extract a 500 mL wastewater sample. Sample extracts were reconstituted in ethyl acetate and analyzed on a Shimadzu GCMS-QP2020 gas chromatograph-mass spectrometer (GC/MS) installed with an Agilent J&W HP-5MS (30 m × 0.25mm, 0.25 µm) column. Injection volume, flow rate, oven temperature, and ion source scan rate were optimized to develop an untargeted full scan method for the detection of pharmaceuticals. Calibration curves were developed for 42 targeted drugs. A 1 µL sample volume is run with a splitless injection utilizing helium as the carrier gas and the instrument operated in constant flow mode at a rate of 1.0 mL/min. The GC oven program is held at the initial temperature of 70°C for 2 min then ramped at 15°C/min to 300°C and held for 10 min for a total run time of 27.33 min. The injection port, transfer line, and source were set at 250°C, 280°C, and 200°C respectively. The MS operated in full scan mode, scanning ions from 35-550 m/z at an event time of 0.20 seconds from 3.50-27.33 minutes. Out of a 42 drug panel, over 75% of the generated calibration curves were suitable for quantitation with coefficients of determination greater than 0.9875. Limits of detection for most drugs ranged from 0.10-1.0 ng/mL, on par with many targeted liquid chromatography methods. The optimized untargeted method is able to detect a wide range of compounds in addition to those in the drug panel. The untargeted full scan MS method supports monitoring a wider range of pharmaceuticals overlooked in traditional targeted waste water methods such as changing trends in novel psychoactive substances.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-18-2020

Available for download on Tuesday, May 18, 2021

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