Journal of the Mass Spectrometry Society of Japan
Online ISSN : 1880-4225
Print ISSN : 1340-8097
ISSN-L : 1340-8097
43 巻, 3 号
選択された号の論文の2件中1~2を表示しています
報文
  • Kenzo HIRAOKA, Konosuke MURATA, Ichiro KUDAKA
    1995 年 43 巻 3 号 p. 127-138
    発行日: 1995年
    公開日: 2007/07/20
    ジャーナル フリー
    The positive and negative ion formations from electrosprayed neutral, basic, and acidic aminoacid (M) solution were investigated as a function of concentrations of CH3COOH and NH3 added in solution. For neutral aminoacids, ammonia solution gave as strong (M+H)+ ion signal as acetic acid solution in the positive ion mode. In the negative ion mode, a strong (M-H)- ion signal appeared from acetic acid solution. For basic aminoacids, ammonia solution of histidine and lysine gave strong (M+H)+ ion signals. For acidic aminoacids, fairly strong (M+H)+ ions for aspartic and glutamic acids were observed from ammonia solution. These experimental results clearly indicate that the ions produced from the electrosprayed charged liquid droplets do not reflect the equilibrium concentrations of ions in solution. The appearances of (M+H)+ ions from electrosprayed ammonia solution and (M-H)- ions from electrosprayed acetic acid solution are due to the protonation and deprotonation of M by NH4+ and by CH3COO- ions, respectively, in the electrosprayed liquid droplets.
  • Hisayuki YAZAWA, Ryoichi SHISHIDO, Tatsuo ARIKAWA
    1995 年 43 巻 3 号 p. 139-148
    発行日: 1995年
    公開日: 2007/07/20
    ジャーナル フリー
    Dynamical properties of amino acid tryptophan molecules seeded in a pulsed supersonic expansion of carrier argon gas have been investigated. Few experiments have been performed so far to obtain the cooling mechanisms of the seeded beam especially in a pulse operation. Measurements relating to the non-equilibrium effects, i.e., the velocity slip, the temperature slip and other important terminal properties of seeded molecular beams have been carried out with the use of a fast optical imaging technique. The flow velocities attained to 99.3% of the ternimal flow velocity for carrier argon gas (~8 K) and 98.9% for seeded tryptophan molecules (~12 K), respectively.
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