Journal of the Mass Spectrometry Society of Japan
Online ISSN : 1880-4225
Print ISSN : 1340-8097
ISSN-L : 1340-8097
41 巻, 4 号
選択された号の論文の5件中1~5を表示しています
報文
  • Keisuke NAGAO, Yayoi N. MIURA, Masako SHIMA
    1993 年 41 巻 4 号 p. 191-209
    発行日: 1993年
    公開日: 2007/07/20
    ジャーナル フリー
    Noble gas concentrations and isotopic ratios were measured for 12 Japanese chondrites. Cosmic-ray exposure ages and gas retention ages obtained for these chondrites are discussed with those for other Japanese chondrites already reported. Cosmic-ray exposure ages of L chondrites range from 5 to 60 Ma without clear cluster, while H chondrites belong to two clusters around 7 and 30~40 Ma. More than half of L chondrites have U, Th-He, and K-Ar ages lower than 3.0 Ga, indicating gas loss by shock event. The concentrations of trapped Ar, Kr, and Xe agree with those inferred from correlation reported between the trapped gas content and the petrographic type. Shiraiwa (H4), find, is the only exception, whose Xe concentration is in the range of type 6. Noble gas data confirm that Kariyasu is a fragment of the Mino (Gifu) metrorite shower, and Hashima and Kasamatsu are different falls. The enstatite chondrite Kishima has a low concentration of subsolar noble gas component. Because the measured concentrations of the subsolar type noble gases are lower than reported ones in Fukutomi (L4-5), the carrier which provide such noble gases should be heterogeneously distributed in Fukutomi.
  • 北 重公, 井上 鋒朋
    1993 年 41 巻 4 号 p. 211-223
    発行日: 1993年
    公開日: 2007/07/20
    ジャーナル フリー
    A time-of-flight analyzer with the path length 2.2 m has been constructed and tested by employing a pulsed ion gun. The optimum time resolution achieved in this analyzer was t/Δt = 6500. The time-of-flight apparatus was used for velocity analysis of fast Li atoms produced by charge exchange reactions in moderate energy Li+-Li collisions. The pulsed alkali-ion beams with time duration of a few ns have been formed by chopping the well-collimated continuous beams. For the pulsing a negative square-wave voltage was applied to a pair of condenser plates.
  • Shigeo HAYAKAWA, Norihisa TERAZAWA, Toshio SUGIURA
    1993 年 41 巻 4 号 p. 225-234
    発行日: 1993年
    公開日: 2007/07/20
    ジャーナル フリー
    Using a beam-gas technique, double electron transfer cross sections of non-dissociative C2- and C2H- ion formations with a Cs target were evaluated to be 7.03 × 10-18 and 1.87 × 10-18 cm2 at laboratory energy of 3.0 keV, respectively. The cross sections of C2- and C2H- ion formation decreased with the decrease of the laboratory energy, becoming 2.15×10-18 and 3.41 × 10-19 cm2 at 0.7 keV, respectively. The cross sections of double electron transfer with K or Na targets were estimated to be less than 2 × 10-20 cm2 at collision energy between 0.7 keV and 3.0 keV. The energy dependence and the magnitude of the cross sections were compared with an adiabatic criterion and Landau-Zener approximation. The Landau-Zener approximation gave the cross sections which were one order of magnitude larger than the experimental value. This difference between the calculated value and the experimental value would be explained from the influence of intermediate pseudopotential crossings between an ion pair state and excited ion molecule states.
  • 鳥羽 文緒, 安藤 昌幸, 浜田 司, 粟田 則男, 津田 敏亘, 木下 邦明
    1993 年 41 巻 4 号 p. 235-243
    発行日: 1993年
    公開日: 2007/07/20
    ジャーナル フリー
    A gas chromatography-mass spectrometric method was employed for the determination of the antispasmodic drug, eperisone, in plasma. Excellent sensitivity was achieved by the selection of the base ion peak at m/z 98 of eperisone and a suitable internal standard, tolperisone, and by using a cyanopropylphenyl-bonded fused-silica capillary column. The lower limit of sensitivity was 10 pg/ml with a signal-to-noise ratio of 3. Another internal standard, decadeuterium labelled eperisone, was inferior to tolperisone in terms of accuracy and reproducibility at low levels of eperisone. The present method allows the determination of eperisone in human plasma after an oral administration of eperisone hydrochloride.
  • 井上 嘉則, 川端 克彦
    1993 年 41 巻 4 号 p. 245-252
    発行日: 1993年
    公開日: 2007/07/20
    ジャーナル フリー
    Inductively coupled plasma mass spectrometry (ICP/MS) was applied to analysis of organotin compounds after separation by micellar liquid chromatography (MLC). Chlorides of dimethyltin (DMT), trimethyltin (TMT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT), triphenyltin (TPT) were separated within 20 minutes by using tris(hydroxymethyl) aminomethane lauryl sulfate as a mobile phase and butyl group bonded silica gel as a stationary phase. Subsequently eluates were directly introduced into ICP/MS and detected at m/z=120. Detection limits for six organotin compounds were from 24 to 51 pg as Sn element. The dynamic range was over 104, from 1 μg/l to 10 mg/l. The repeatability was better than 3% of the relative standard deviation (RSD) for all organotin compounds.
feedback
Top