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FAST ATOM BOMBARDMENT MASS SPECTROMETRY FOR STRUCTURE DETERMINATION OF PLANT TOXINS AND FOURIER TRANSFORM MASS SPECTROMETRY FOR LASER DESORPTION OF BIOMOLECULES
Abstract
Chapter 1. The structure of HC-toxin, isolated from Helminthosporium carbonum, was verified by using mass spectrometry and fast atom bombardment ionization followed by collision activated dissociation of mass selected ions. Results from high resolution electron impact and chemical ionization mass spectra aided in ion identification. Also, the structure of a nontoxic "conversion product" of HC-toxin and of a glycine analog of HC-toxin were determined. The structures of toxic metabolites from Phyllosticta maydis, PM-toxins A, B, C, and D, were deduced by analyzing a number of different derivatives by electron impact mass spectrometry. Fast atom bombardment ionization was used to obtain the molecular weights and molecular formulae of the free toxins. Chapter 2. General characteristics of laser desorption mass spectrometry and the analytical capabilities of Fourier transform mass spectrometry are discussed. Initial results demonstrating the feasibility of laser desorption-Fourier transform mass spectrometry are presented with instrumental and procedural improvements that extend its range of application to biomolecules. Results concerning the mechanism of cationization of neutral molecules and the shot-to-shot spectral reproducibility are also presented. Chapter 3. Mass spectra of alkyltriphenylphosphonium halides were obtained by using fast atom bombardment coupled with tandem mass spectrometry (MS/MS) and laser desorption with Fourier transform mass spectrometry. In addition, collision activated dissociation spectra of laser desorbed phosphonium ions were obtained. The two methods of ionization are equally useful in determining molecular weights of the phosphonium ions. However, high-energy collisional activation is needed to obtain unambiguous structural confirmation of the alkyl group. In addition, ion abundance ratios provide information about the internal energy of the phosphonium ions produced by fast atom bombardment and laser desorption.
Subject Area
Analytical chemistry
Recommended Citation
MCCRERY, DAVID ALLAN, "FAST ATOM BOMBARDMENT MASS SPECTROMETRY FOR STRUCTURE DETERMINATION OF PLANT TOXINS AND FOURIER TRANSFORM MASS SPECTROMETRY FOR LASER DESORPTION OF BIOMOLECULES" (1985). ETD collection for University of Nebraska-Lincoln. AAI8521463.
https://digitalcommons.unl.edu/dissertations/AAI8521463