title: Atmospheric-pressure Penning ionization mass spectrometry.
abstract: A preliminary study on the atmospheric-pressure Penning ionization (APP(e)I) of gaseous organic compounds with Ar* has been made. The metastable argon atoms (Ar*: 11.55 eV for (3)P(2) and 11.72 eV for (3)P(0)) were generated by the negative-mode corona discharge of atmospheric-pressure argon gas. By applying a high positive voltage (+500 to +1000 V) to the stainless steel capillary for the sample introduction (0.1 mm i.d., 0.3 mm o.d.), strong ion signals could be obtained. The ions formed were sampled through an orifice into the vacuum and mass-analyzed by an orthogonal time-of-flight mass spectrometer. The major ions formed by APP(e)I are found to be molecular-related ions for alkanes, aromatics, and oxygen-containing compounds. Because only the molecules with ionization energies less than the internal energy of Ar* are ionized, the present method will be a selective and highly sensitive interface for gas chromatography/mass spectrometry.
authors.affiliation: Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu 400-8511, Japan. hiraoka@ab11.yamanashi.ac.jp
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hiraoka
authors.forename: Susumu
authors.initials: S
authors.lastname: Fujimaki
authors.forename: Shizuka
authors.initials: S
authors.lastname: Kambara
authors.forename: Hiroko
authors.initials: H
authors.lastname: Furuya
authors.forename: Shigemitsu
authors.initials: S
authors.lastname: Okazaki
mesh_terms: D001128:Argon / Q000032:analysis* / Q000737:chemistry; D001274:Atmospheric Pressure; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005740:Gases / Q000032:analysis* / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods*
chemical_list: D005740:Gases; D009930:Organic Chemicals; D001128:Argon