Gaining of analytical information about a compound for structural group analysis using mass spectra of negative ions

Abstract

Successful functioning of expert systems designed for determination of the molecular structure of organic compounds by spectral characteristics requires the availability of most complete initial analytical information. Successful functioning of expert systems designed for determination of the molecular structure of organic compounds by spectral characteristics requires the availability of most complete initial analytical information which necessitates summarizing and using data gained in different analytical methods. We consider prospects of gaining new information about test compounds by the method of resonant electron capture negative ion mass spectrometry using a serial quadrupole mass-spectrometer. A number of phosphorus-containing organic compounds are used to demonstrate a possibility of recording mass spectrum peaks of deprotonated molecules, which is rather important for determination of the molecular mass and, hence, correct identification of the compound. Examples of successful detection of the fragments with positive electron affinity present in the structure of compounds under study are listed. The obtained results substantially differ from that obtained by the “classical” method of electron ionization positive ion mass spectrometry and can be considered as a complementary data about the structure of compounds for the purposes of structural group analysis., We also present the results of experiments in which mass spectra of negative ions were obtained using the advanced cathode power supply device via multiple change in the energy of ionizing electrons during the analysis. The possibility of implementing both analytical methods on the same device is an additional advantage of this approach.