Fourier transform mass spectrometry of polymers and copolymers

The history and ion formation mechanisms of soft ionization techniques are summarized in Chapter I. Basic principles of Fourier transform mass spectrometry (FTMS) and tandem mass spectrometric techniques are reviewed in Chapter II and a polymer and copolymer background in Chapter III.;A wide mass range trapping experiment using internal source matrix-assisted laser desorption FTMS (MALDI-FTMS) is described in Chapter IV. In this method, the front trap plate potential is ramped up and the rear trap plate potential is simultaneously decreased using a cubic cell to trap ions over a wide range of mass-to-charge ratios. To apply this to tandem mass spectrometry experiments, a second ion ejection procedure would remove unwanted ions, with the selected remaining ions then fragmented by collision-induced dissociation.;In Chapter V tandem FTMS of homopolymers and copolymers is discussed. In recent years, many fragmentation techniques have been developed for use with FTMS in sequencing polymers. High resolution FTMS analysis of fragments produced by collision cell collision-induced dissociation (QCID) is available in a new generation hybrid FTMS instrument. Although tandem QCID-TOF techniques have been used heavily to explore copolymer fragmentation, we report the first QCID-FTMS analysis of such systems. The high fragmentation efficiency of QCID combined with the high mass resolution and mass accuracy of FTMS reveals a novel fragmentation pattern of selected oligomers. Using QCID-FTMS technique it was possible to differentiate random copolymers from block copolymers. The electron capture dissociation (ECD) FTMS spectra of polyacrylates showed only side group losses.;Chapter VI describes analysis of thin films deposited on silicon by direct laser desorption/ionization (LDI) FTMS. High-resolution mass spectra showed the presence of carbon clusters and hydrocarbon oligomers in different relative abundances. Films produced by unipolar and continuous discharge polymerization technique had smooth surfaces and the corresponding LDI-FTMS spectra displayed only carbon cluster signals in the positive ion mode and both hydrocarbon and carbon cluster signals (with much higher relative abundance of carbon cluster signals) in the negative ion mode. LDI-FTMS spectra of thin films produced by bipolar discharge showed either total absence or lower relative abundance of carbon cluster signals, compared with hydrocarbon signals. Additional discussion of thin film analysis by FTMS is presented in Chapter VII.;Additionally in Chapter VIII, particle velocity determination in a sampling stage of the novel aerosol Fourier transform mass spectrometer is described.