The development of an ion-molecule reaction-based mass spectometric method for the identification of protonated monofunctional nitrogen-containing compounds and a study on the chemical reactivity of o-benzyne derivatives by using Fourier transform ion cyclotron resonance mass spectrometry (FT -ICR)
Abstract
Rapid identification and characterization of drug degradation products within a mixture is important in the pharmaceutical industry. Mass spectrometry/mass spectrometry (MS/MS) is a sensitive technique well-suited for direct mixture analysis. Tandem mass spectrometric techniques, such as collision-activated dissociation of mass-selected analyte ions, provide connectivity information for the analytes. However, this method cannot be used to unambiguously identify the functional groups in an unknown analyte. Therefore, other methods are needed to accurately assess the analyte’s structure. MS/MS experiments utilizing ion-molecule reactions are a promising approach for functional group identification. Chapters 3 and 4 of this thesis discuss the development of a method to identify protonated nitrogen-containing analytes with the use of ion-molecule reactions. These chapters focus on reactions between a neutral aminoborane and various protonated analytes in an FT-ICR and a triple quadrupole mass spectrometer. Chapter 3 discusses a method that can be used to screen for the presence of the amido functionality in monofunctional protonated analytes. Chapter 4 discusses a method utilizing solution derivatization reactions prior to mass spectrometric analysis for the identification of the amino functionality in mono- and bifunctional amines. Chapter 5 presents the implementation of this method on a known drug sample. The final chapter describes a gas-phase reactivity study on three isomeric o-benzyne derivatives carried out by using the distonic ion approach. The o-benzyne derivatives were found to react via nonradical addition/elimination pathways. Further, greater reaction efficiencies were measured for the most electrophilic o-benzynes.
Degree
Ph.D.
Advisors
Kenttamaa, Purdue University.
Subject Area
Organic chemistry
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