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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Paper spray mass spectrometry (PS-MS) for toxicological drug screens and biomonitoring of chemical warfare agent exposure

McKenna, Josiah Michael January 2017 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Paper spray is an ambient ionization technique for mass spectrometry that is well-known for its ability to accomplish rapid and sensitive analyses without any need for sample preparation. This work further develops the technique in two major areas: negative ionization and drug screening. Negative ionization has always been an obstacle to electrospray-based ion sources because of its vulnerability to corona discharge, but methods are presented here to both quantify and suppress this electrical phenomenon, thus preventing it from interfering with qualitative/quantitative analyses. The validity of the discharge-suppressing method is demonstrated for both a simple screen of barbiturates and other acidic drugs (Chapter 2) and the detection and quantitation of chemical warfare agent hydrolysis products (Chapter 3). Additionally, a positive ion drug screen is applied to the analysis of postmortem blood samples (Chapter 4), achieving rapid and effective screening of 137 different drugs ranging from pharmaceuticals to drugs of abuse. The performance of this screen is also evaluated by comparing the results of the postmortem samples to those obtained using a more established series of assays. The research contained herein presents strides toward forensic application of paper spray mass spectrometry, especially in disciplines related to forensic toxicology.
12

Detection and Quantitation of Hazardous Chemicals in Environmental Matrices using Paper Spray Mass Spectrometry

Dowling, Sarah Naciye 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Paper spray mass spectrometry (PS-MS) is an ambient ionization technique that has been proven useful in many types of investigative analyses. However, the use of this technique with regards to environmental samples has been largely unexplored since the technique’s development. In this work, paper spray mass spectrometry was utilized to detect and quantify compounds for environmental, forensic and chemical defense applications. Due to the sensitive nature of some projects, the work was split into two volumes. Volume 1 focuses on the detection of pharmaceuticals in soil using paper spray (Chapter 2) and the detection of chemical warfare agent (CWA) simulants and CWA hydrolysis products (Chapter 3). Volume 2 focuses on the detection and quantitation of fentanyl analogs in environmental matrices. Chapter 5 focuses on the rapid analysis of fentanyl analogs in soil matrices. The following chapter evaluates the ability of PS-MS to detect low concentrations of fentanyl analogs in water (Chapter 6). Throughout this work, paper spray has proven to be an effective, rapid alternative to chromatography for the analysis of environmental samples.
13

Development of Functionalized Paper-Based Sample Collection and Direct Mass Spectrometry Analysis Platforms

Damon, Deidre Erin 03 September 2019 (has links)
No description available.
14

Paper Spray - Mass Spectrometry: Investigation of Sampling Devices for Illicit Drug Detection and Quantification

Chau Bao Nguyen (11178123) 06 August 2021 (has links)
Different sampling devices for paper spray - mass spectrometry (PS - MS) were investigated to improve the assay’s simplicity and sensitivity over traditional approaches. In the first one, pressure-sensitive adhesive paper was used as both sampling tool to collect drug residues on surfaces and paper substrate in PS - MS analysis. This method showed a significant improvement in drug collection on surfaces leading to low nano-gram level detection limits. Other sampling device being investigated was snap-in solid-phase extraction column, which demonstrated the ability to detect trace amounts of drugs in plasma while allowed easy transportation and the use of PS - MS automated system.
15

Development of Substrate-based Ambient Ionization Techniques for Direct Sampling by Mass Spectrometry

Jackson, Sierra January 2021 (has links)
No description available.
16

PAPER SPRAY-MASS SPECTROMETRY COUPLED WITH PRESSURE-SENSITIVE ADHESIVE-BASED COLLECTION FOR THE RECOVERY AND DETECTION OF DRUGS OF ABUSE

Sarah Prunty (16631748) 30 August 2023 (has links)
<p> Illicit drug abuse is a widespread issue in the United States and worldwide. Many methods  seek to ease the analytical workload required to collect, analyze, and identify these drugs. Paper  spray-mass spectrometry (PS-MS) is one response to this analytical workload as it offers a rapid,  affordable, and simple means for drug identification by mass spectrometry. This work centers on  the use of pressure-sensitive adhesive (PSA) lined paper as a PS-MS substrate for drug recovery  and detection. The use of PSA paper as a sampling and analysis substrate has been previously  established but is expanded herein with new capabilities and applications. Chapter 2 introduces  the combination of color tests followed by PS-MS for presumptive and confirmatory drug  identification. Three color tests (cobalt thiocyanate, Simon, or Marquis) were performed on the  PSA paper with subsequent drug confirmation occurring by PS-MS. Chapter 3 examines the use  of PSA paper and PS-MS for the recovery and detection of fentanyl, fentanyl precursors, and  analogs from shipping-related surfaces and in the presence of high amounts of cutting agents. The  use of a cartridge that accommodates a full-sized PSA paper ticket was also explored for drug  detection. Chapter 4 assesses PS-MS with PSA paper on portable MS instrumentation. Analyte  recovery and carryover as well as instrument robustness were evaluated. The color test and PS-MS protocol examined in Chapter 2 was also successfully applied to a portable MS instrument.  Application of PS-MS to the portable system highlights the potential fieldability of the technique. </p>
17

Detection and Quantitation of Hazardous Chemicals in Environmental Matrices using Paper Spray Mass Spectrometry: Volume 2

Sarah Dowling (6944351) 16 October 2019 (has links)
<p>Paper spray mass spectrometry (PS-MS) is an ambient ionization technique that has been proven useful in many types of investigative analyses. However, the use of this technique with regards to environmental samples has been largely unexplored since the technique’s development. In this work, paper spray mass spectrometry was utilized to detect and quantify compounds for environmental, forensic and chemical defense applications. Due to the sensitive nature of some projects, the work was split into two volumes. Volume 1 focuses on the detection of pharmaceuticals in soil using paper spray (Chapter 2) and the detection of chemical warfare agent (CWA) simulants and CWA hydrolysis products (Chapter 3). Volume 2 focuses on the detection and quantitation of fentanyl analogs in environmental matrices. Chapter 5 focuses on the rapid analysis of fentanyl analogs in soil matrices. The following chapter evaluates the ability of PS-MS to detect low concentrations of fentanyl analogs in water (Chapter 6). Throughout this work, paper spray has proven to be an effective, rapid alternative to chromatography for the analysis of environmental samples. </p>
18

Paper Spray - Mass Spectrometry: Investigation of Sampling Devices for Illicit Drug Detection and Quantification

Nguyen, Chau Bao 07 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Paper spray - mass spectrometry (PS-MS) has been developed as a rapid and direct ionization method for qualitative and quantitative analysis of complex samples at trace levels. In this work, different sampling devices for PS-MS were investigated to improve the assay’s simplicity and sensitivity over traditional approaches. In particular, chapter two characterizes an alternate paper substrate to enhance drug detection on surfaces like asphalt, cloth, concrete, aluminum, and glass. Analysis occurs on a single spray ticket coated with pressure-sensitive adhesive (PSA), also known as Post-it notes to detect and quantify drug residues. A PS-MS method utilizing PSA paper was developed to detect a mixture of ten drugs off of various surfaces to evaluate the qualitative and quantitative capabilities of the aforementioned substrate. After the method development on a conventional linear ion trap mass spectrometer, the assay was translated for use on a portable mass spectrometer to evaluate the suitability of the pressure-sensitive adhesive paper substrate in the field in chapter three. Chapter four introduces a sampling device combined with a snap-in solid-phase extraction (SPE) column. The new cartridge design not only inherits the functions from the first iteration SPE cartridge, including extraction and preconcentration from complex samples, but also exhibits greater flexibility in volume control and ease of use for on-site sample collection.
19

Characterization of Three-Dimensional Dried Blood Spheroids: Applications in Biofluid Collection, Room Temperature Storage, and Direct Mass Spectrometry Analysis

Frey, Benjamin Steven 19 September 2022 (has links)
No description available.
20

Development of Mass Spectrometry-Based Analytical Assays for Environmental and Defense Applications

Sarah Dowling (6944351) 03 January 2024 (has links)
<p dir="ltr">Mass spectrometry (MS) is a powerful and versatile technique that is useful for addressing a wide range of complex analytical challenges. In this work, mass spectrometry-based assays were developed to address issues relating to environmental contamination and for detecting analytes of interest to the defense industry. Chapter one is an overview of the history of mass spectrometry, the fundamental operation of a mass spectrometer, as well as, advancements in chromatographic separation and ionization methods. Chapter two focuses on the development of an assay that uses blow flies as environmental sensors of chemical weapon release. In that work, a liquid chromatography – tandem mass spectrometry (LC-MS/MS) method was developed to detect chemical warfare agent simulants and chemical warfare agent hydrolysis products in flies exposed to the chemicals in controlled feeding experiments. The work in chapter three describes the development of a surface enhanced Raman spectroscopy assay coupled to paper spray mass spectrometry for a more fieldable and environmentally friendly approach to detect organophosphorus compounds. Chapter four describes the development of a paper spray mass spectrometry assay for the detection and semi-quantitation of per- and polyfluoroalkyl substances in whole blood without sample cleanup or chromatographic separations. This method would be useful in detecting high levels of these carcinogenic compounds in individuals highly exposed via their occupations. The final chapter (chapter five) returns to using blow flies as environmental sensors, but this time to detect insensitive munitions in the environment. The work focuses on the development of two different liquid chromatography mass spectrometry methods for the detection of insensitive munitions, which are less shock sensitive explosives, and their transformation products in the environment. Controlled feeding experiments were also performed where flies were exposed to contaminated soil and water sources to show the feasibility of this method in a more realistic scenario. The projects detailed herein show the extensive range with which mass spectrometry can be used for the detection of harmful chemistries of environmental concern.</p>

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