| Abstract: | Not only strong differences in relative abundances of product ions, but also different fragmentation pathways are observed in the electron impact mass spectrosopy of six stereoisomeric cyclohexanehexacarboxylic methyl esters. This unusual behaviour has been studied in detail with the aid of different ionization methyods, B/E and B2/E linked scans, exact mass measurements, deuterium labelling experiments and collisionally activated decomposition spectrometry. A close analogy between the isomerization observed under acidic conditions in condensed phase and that observed under chemical ionization (CH4) conditions is underlined. |
