Abstract
We have set up an ion trapping mass spectrometer for time resolved analysis from a conventional mass spectrometer (EI/MS), according to the technique established by Harrison et al. and Lifshitz. After comfirming ion trapping ability of this apparatus by use of toluene, the peaks of m/z 105, 106, and 107 (called A1, A2, and A3, respectively) of benzaldehyde have been investigated. Although the signal intensities of three peaks at delay time zero have been similar to those of the spectrum obtained by static method, they have different behaviors after 100 μs. In other words, the intensities of A1 and A3 have increased gradually with time, while, that of A2 has decreased. The aspects of increase and decrease have been noticed to be dependent on pressure of sample. These results can not be explainable by the well known fragmentation process. To explain these results, we are proposing that 1) electron capturing of molecular ions, 2) ion-molecule reactions of ions and molecules of benzaldehyde, and 3) metastable decomposition, take place in the ionic chamber.
