title: Gas chromatographic-ion trap mass spectrometric analysis of volatile organic compounds by ion-molecule reactions using the electron-deficient reagent ion CCl3(+).
abstract: When using tetrachloromethane as the reagent gas in gas chromatography-ion trap mass spectrometry equipped with hybrid ionization source, the cation CCl(3)(+) was generated in high abundance and further gas-phase experiments showed that such an electron-deficient reagent ion CCl(3)(+) could undergo interesting ion-molecule reactions with various volatile organic compounds, which not only present some informative gas-phase reactions, but also facilitate qualitative analysis of diverse volatile compounds by providing unique mass spectral data that are characteristic of particular chemical structures. The ion-molecule reactions of the reagent ion CCl(3)(+) with different types of compounds were studied, and results showed that such reactions could give rise to structurally diagnostic ions, such as [M+CCl(3) - HCl](+) for aromatic hydrocarbons, [M - OH](+) for saturated cyclic ether, ketone, and alcoholic compounds, [M - H](+) ion for monoterpenes, M(·+) for sesquiterpenes, [M - CH(3)CO](+) for esters, as well as the further fragment ions. The mechanisms of ion-molecule reactions of aromatic hydrocarbons, aliphatic ketones and alcoholic compounds with the reagent ion CCl(3)(+) were investigated and proposed according to the information provided by MS/MS experiments and theoretical calculations. Then, this method was applied to study volatile organic compounds in Dendranthema indicum var. aromaticum and 20 compounds, including monoterpenes and their oxygen-containing derivatives, aromatic hydrocarbon and sesquiterpenes were identified using such ion-molecule reactions. This study offers a perspective and an alternative tool for the analysis and identification of various volatile compounds.
authors.affiliation: Research Center for Health and Nutrition, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China.
authors.forename: Cheng-Zhong
authors.initials: CZ
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Su
authors.forename: Hao-Yang
authors.initials: HY
authors.lastname: Wang
authors.forename: Yin-Long
authors.initials: YL
authors.lastname: Guo
mesh_terms: D002251:Carbon Tetrachloride / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D031202:Chrysanthemum / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D039821:Monoterpenes / Q000032:analysis / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000737:chemistry
chemical_list: D002412:Cations; D039821:Monoterpenes; D010936:Plant Extracts; D055549:Volatile Organic Compounds; D002251:Carbon Tetrachloride