Material Type  

 학위논문

 

0016932536

Date and Time of Latest Transaction  

20240214100511

ISBN  

9798379679408

DDC  

545

Author  

Easterling, Leah F.

Title/Author  

Atypical Mass Spectrometry Approaches for Unknown Analyte Identification in Complex Mixtures - [electronic resource]

Publish Info  

[S.l.] : Purdue University., 2020

Publish Info  

Ann Arbor : ProQuest Dissertations & Theses, 2020

Material Info  

1 online resource(149 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 84-12, Section: B.

General Note  

Advisor: Wirth, Mary.

학위논문주기  

Thesis (Ph.D.)--Purdue University, 2020.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Abstracts/Etc  

요약This dissertation details three studies which utilize nontraditional applications of electrospray ionization mass spectrometry. The first study explores and discusses the limitations of identifying unknown drug metabolites using ion-molecule reactions performed inside a mass spectrometer and coupled with high performance liquid chromatography. Ultimately, it was concluded that some highly-efficient, MS2 ion-molecule reactions coupled with some drug metabolites would be sufficiently sensitive for in vivo drug metabolism studies. However, this study also concluded that the rate of false-positives and false-negatives may be higher than previous publications suggest.The next study analyzed sulfur-containing compounds under atypical negative-mode electrospray ionization mass spectrometry conditions. After noting that low analyte flow rates during electrospray ionization experiments on ethanethiol resulted in significant oxygen incorporation, the aim of this study was to understand the chemistry behind the oxygen incorporation and search for ways to experimentally limit the degree of oxygen inclusion. The atypical conditions were ultimately shown to induce significant ozonolysis and other oxidation reactions. Ultimately, only the use of high flow rates or switching to a different ionization technique were successful in mitigating the oxidation product formation. A new reaction mechanism for the oxidation of ethanethiol with ozone was proposed. Quantum chemical calculations were used to support the mechanism.Finally, electrospray ionization mass spectrometry was used to analyze mixtures of selenium and/or tellurium in amine-thiol solvent systems. Selenium and tellurium are essential components in many thin film solar cells and other photovoltaics and amine-thiol solvent systems have been identified as a key solution processing strategy for synthesizing selenium and tellurium thin films. However, the reaction between selenium/tellurium and the amine-thiol solvent system is poorly understood and requires detailed study before large-scale industrial synthesis can be achieved. In this study, the dissolution mechanisms for selenium and tellurium in two different amine-thiol solvent systems were explored and discussed. The role of the basicity of the amine, the relative concentration of the thiol, and the presence of co-dissolved chalcogens were all studied and used to propose dissolution mechanisms. The results of the experiments were used to control the synthesis of lead-selenium-tellurium alloy nanoparticles and could inform further studies on controlling metal chalcogenide synthesis through the appropriate choice of amine-thiol solvents.

Subject Added Entry-Topical Term  

Mass spectrometry.

Subject Added Entry-Topical Term  

Oxidation.

Subject Added Entry-Topical Term  

Pharmaceuticals.

Subject Added Entry-Topical Term  

Solvents.

Subject Added Entry-Topical Term  

Electric fields.

Subject Added Entry-Topical Term  

Sensors.

Subject Added Entry-Topical Term  

Atmospheric pressure.

Subject Added Entry-Topical Term  

Chemistry.

Subject Added Entry-Topical Term  

Selenium.

Subject Added Entry-Topical Term  

Scientific imaging.

Subject Added Entry-Topical Term  

Ion beams.

Subject Added Entry-Topical Term  

Chromatography.

Subject Added Entry-Topical Term  

Metabolites.

Subject Added Entry-Topical Term  

Nitrogen.

Subject Added Entry-Topical Term  

Analytical chemistry.

Subject Added Entry-Topical Term  

Atmospheric sciences.

Subject Added Entry-Topical Term  

Electromagnetics.

Subject Added Entry-Topical Term  

Pharmaceutical sciences.

Subject Added Entry-Topical Term  

Physics.

Added Entry-Corporate Name  

Purdue University.

Host Item Entry  

Dissertations Abstracts International. 84-12B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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소장사항  

202402 2024

Control Number  

joongbu:640932