Document Type

Dissertation - Open Access

Award Date

2020

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry and Biochemistry

First Advisor

Brian Logue

Abstract

Environmental pollution from contaminants is a serious concern in a world where more and more pesticides and pharmaceuticals are being used, sometimes improperly and in excess. Since pesticides are used on practically every crop on Earth, it’s no surprise that these compounds are detected in soil, water, and processed agricultural commodities meant for human consumption. Additionally, because of the ubiquity of pharmaceuticals, specifically opioids, and their inherent addictive properties, these compounds are being over-consumed. Because current waste-water treatments can be insufficient to remove them from water sources, this consumption has led to the detection of these compounds in drinking water. Other man-made compounds, including per- and polyfluoroalkyl substances (PFAS), have also been detected in drinking water. There has been evidence of these compounds causing various health issues, including cancer. The ability to detect pesticides, opioids, and PFAS at ultratrace concentrations is vital; therefore, Ice Concentration Linked with Extractive Stirrer (ICECLES) and direct injection, in conjunction with high performance liquid chromatography—tandem quadrupole mass spectrometry (HPLC-MS/MS), were used for their detection at ultratrace levels. Due to the inherent danger of water and soil contamination with pesticides, PFAS, and opioids, their detection at ultratrace concentrations is vital, as their chronic effect on human health, even at low concentrations, is relatively unknown. Therefore, several analytical methods were developed, validated, and applied to the analysis of field samples to detect these contaminants in soil and water from across the U.S. For soil, a method was developed for the analysis of atrazine in soil that generated a Limit of Detection (LOD) and Limit of Quantification (LOQ) of 5 and 10 ng/kg, respectively. This method required minimal extraction and generated an LOQ 100x lower than the next most-sensitive method. This soil method was able to detect atrazine in various U.S. soils. For drinking water analysis, a method to detect PFAS was developed. This method required only 50 μL of organic solvent (methanol) for each sample, no SPE cleanup, no filtration and/or evaporation and reconstitution, while generating ultratrace LODs and LOQs for the 14 PFAS tested. This method was then applied to various U.S. drinking water samples and detected values as high as 213 ng/L. The developed opioid method generated LODs and LOQs for all three compounds ranging from 0.15 to 1.5 and 0.5 to 5.0 pg/mL, respectively. After validation, the method was applied to the analysis of various U.S. drinking water samples and detected hydrocodone and codeine with a prevalence of 79%. In addition, there is no previous study reporting opioid concentrations in U.S. drinking water sources, and so this work provides a simple, direct injection analysis for opioids in drinking water not previously reported. Lastly, using atrazine as a probe molecule, an extensive evaluation of ICECLES compared to other techniques, liquid-liquid extraction (LLE), solid phase extraction (SPE), stir bar sorptive extraction (SBSE), and solid phase micro-extraction (SPME), with analysis via HPLC-MS/MS was performed. ICECLES, SBSE, and SPME extractions of five compounds (atrazine, furfural, 2-methylpyrazine, 1- pentanol, and indole) from water were also compared.

Library of Congress Subject Headings

Drinking water -- Contamination.
Soil pollution.
Perfluorinated chemicals.
Pesticides.
Opioids.

Format

application/pdf

Number of Pages

163

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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