Studies on Molecular Weight Estimation System of Organic Compounds by High Level Utilization of Ion/Molecule Reactions

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Reactant ion system tend to generate adduct ion and molecular weight estimation method utilizing collisionally activated dissociation (CAD) of adduct ion have been investigated for the purpose of extension of applicationable range of molecular weight estimation in chemical ionization (CI). In case of reactant ion system, NH_4^+ and Cl^- were formed simultaneously using methane/amine hydrochloride mixture, consequently it was possible to produce (M+NH_4)^+ and (M+Cl)^- for many compounds such as succharides and alcohols. In case of methane/water mixture reagent gas, H_3O^+ was formed as reactant ion and it was possible to generate (M+H_3O)^+ for some compounds such as alkanes which usually hadn't adduct ions. In the study of molecular weight estimation utilizing CAD, firstly daughter ion spectra of several kinds ofadduct ions resulting from CAD were investigated. Consequently, it was proved that (M+R)^+ -> R^+ + M {(M+R)^+ : adduct ion, R^+ : reactant ion, M : molecule } and (M+R)^+ -> MH^+ + (R-H) were correlated with the molecular weight estimation and identification of (M+R)^+ was equal to determination ofmolecular weight. In first method, parent ions corresponded to adduct ion candidates produce known reactant ion R^+ were extracted by parent ion scan mode at first, and identification of (M+R)^+ was carried out by confirmation of daughter ion spectra of the ions had peaks corresponding MH^+ and R^+. In second method, firstly parent ions corresponded to adduct ion candidates were extracted in the same way, and identification of (M+R)^+ was achieved by the fact that elimination of neutral species corresponding molecule was observed in neutral loss spectrum. Molecular weight of main constituent of organic sample which was newly synthesized was determined by these methods. These methods were also applicationable to