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Volume 35 (1987)
- Issue 6 Pages 335-
- Issue 5 Pages 226-
- Issue 4 Pages 186-
- Issue 3 Pages 90-
- Issue 2 Pages 42-
- Issue 1 Pages 1-
Volume 35, Issue 3
Displaying 1-5 of 5 articles from this issue
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REGULAR PAPERS
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Hiroshi Mima1987 Volume 35 Issue 3 Pages 90-106
Published: 1987
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA new non-magnetic path separation type mass spectrometer is proposed. Ions injected into the mass separating region are exposed to an electric field which is perpendicular to the direction of the drift motion of the ions. The electric field consists of a pulsed r-f field which appears at each half cycle of the rectangular wave. The field has approximately a parabolic potential distriaution. The period of oscillation of the ions in the field depends on their mass. The drifting and the oscillating motions enable selected ions to reach the ion collector electrode.
Since the r-f frequency relevant to the mass of ions in question is relatively low, frequency sweeping mode of operation may be effective. It yields desirable characteristics of constant transmissivity for selected ions in the mass separation region independent of the ion mass. The operational principle of the mass spetrometer is simple and obvious, which facilitates construction of the electrode. The resolving power was anticipated numerically, being proved to exceed 100 without much difficulty.View full abstractDownload PDF (1076K) -
Hiroshi Mima1987 Volume 35 Issue 3 Pages 108-121
Published: 1987
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe author proposes a new approach to deriving the pattern coefficients of mass spectrometers in terms of such presumably measurable quantities as the partial ionization cross section and others. Firstly, the Intrinsic Pattern Coefficients that are inherent to an ion source are derived in terms of (l vs V) distribution of ionizing electrons and the partial ionization cross section of a sample gas. The (l vs V) distribution gives the transit path length of ionizing electrons as a function of the electron energy. Secondly, the amount of each fragment ion which is lost in the mass analyzing region is estimated. This approach was applied to three vacuum analyzers. The mutual differences in pattern coefficients that exist among them were successfully accounted for.View full abstractDownload PDF (941K) -
Du Wenhu, Chien Kuangnan, Liu Jianli, Duan Zhenying1987 Volume 35 Issue 3 Pages 122-132
Published: 1987
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA new method of analysis was proposed based on the use of permselective membrane which gives the possibility of enriching and analyzing trace volatile organics in waters. A silicone membrane introduction device which is simple and easy to construct was designed to couple with JMS-D300 Mass Spectrometer. A quantitative formula which is available in the Membrane Introduction Mass Spectrometry was deduced. This paper studied the determination of alkanes, aromatic compounds and halogenated organics in waters by MIMS and discussed the effects of equilibrium time, temperature, sample volume, sample matrix etc. on responses of analyzed components. It was found that 22 volatile organics presented a wide linear concentration range from ppb to ppm, detection limits from 0.1 to 10 ppb and recoveries from 90% to 110%.View full abstractDownload PDF (566K) -
Hidetoshi Fujiwara, Akira Kato1987 Volume 35 Issue 3 Pages 134-138
Published: 1987
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe mass spectra of 3-dimethylaminomethylcyclohexanol derivatives (1-5) were measured under a direct inlet system by electron impact ionization, and their characteristic fragmentations are discussed. The characteristic ions in the mass spectra of 1-5 are the fragment ions at m/z 58, m/z 71, m/z 72, m/z 111 and m/z 156. The characteristic peak at m/z 58 is the base peak in the mass spectra of all compounds. The structure of this ion appears to be CH2=N+(CH3)2. The cis-and trans-configurations of 1-5 can be identified by observing the peak intensities at m/z 71, m/z 72 and m/z 156 in the mass spectra and by observing the peak corresponding to loss of a hydrogen molecule from the m/z 84 ion in the ion kinetic energy (IKE) spectra.View full abstractDownload PDF (242K) -
Hidetoshi Fujiwara, Akira Kato, Ichizo Okabayashi1987 Volume 35 Issue 3 Pages 140-146
Published: 1987
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSMass spectra of a series of spiro-benzoxazin-4-one and spiro-quinazolin-4-one derivatives were measured by electron impact ionization, and their characteristic fragmentation patterns were discussed.
Spiro-benzoxazin-4-ones and spiro-quinazolin-4-ones were found to display different fragmentation pathways and different peak intensities. In particular, the base peak in mass spectra of spiro-benzoxazin-4-ones resulted from the molecular ion by the retro-Diels-Alder reaction with hydrogen migration. On the other hand, the base peak in mass spectra of spiro-quinazolin-4-ones resulted from the molecular ion by the cycloalkane ring decomposition. The difference in the main two processes was based on the difference in the ionization energy of the oxygen atom and the nitrogen atom at the 1-position. The difference in hydrogen migration was based on the defference in electronegativity of the heteroatom at the 1-position.View full abstractDownload PDF (442K)
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