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Volume 34, Issue 2
Displaying 1-6 of 6 articles from this issue
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REVIEW
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With due Regard to Enhancement of SelectivityMasataka Ishibashi1986 Volume 34 Issue 2 Pages 71-88
Published: 1986
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSDerivatization plays an important role in microanalysis by GC/SIM and is employed to enhance the GC-performance by involving the properties of derivatives in volatility and thermal stability. In addition, as the sensitivity and the specificity in microanalysis using GC/SIM is expected to enhance by choosing a derivative with a mass spectrum in which ion current is concentrated in a characteristic ion in high mass region, a number of new derivatives have been extensively examined for quantitation of endogenous substances and drugs in biological materials. This paper describes briefly our study on dimethylalkylsilyl ether derivatives and diethylhydrogensilyl-cyclic diethylsilylene derivatives and their application to microanalysis using GC/SIM.View full abstractDownload PDF (1110K)
REGULAR PAPERS
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Yoshiaki Yoshioka, Kazuyoshi Tsukamoto1986 Volume 34 Issue 2 Pages 89-97
Published: 1986
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSIn-depth profiling with secondary ion mass spectrometry has bean used to measure the interface width of OMVPE and LPE InGaAsP/InP, and MBE GaAlAs/GaAs superlattice heterojunctions.
The interface width of InGaAsP/InP heterojunction grown by OMVPE are determined to be ≤16 Å with 1.5 keV Cs+ primary ions. The measured interface width of LPE InGaAsP/InP was found to be ~66 Å at the depth of 260 Å.
GaAlAs/GaAs surface are not uniform due to cone formation when sutter etched by 1.5 keV Cs+ ions, 1.5 keV O2+ ions and 1.5 keV Cs+ ions with oxygen ambient.
Knock-on effect, preferential sputtering and ion induced surface microtopography are discussed with respect to thier influence on depth resolution.View full abstractDownload PDF (974K) -
Susumu Tajima, Seiji Tobita, Akio Negishi, Toshikazu Tsuchiya1986 Volume 34 Issue 2 Pages 99-105
Published: 1986
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSFragmentation process of 1,2-([1]), 1,3-([2]) and 1,4-([3]) benzenedicarboxylic acid dimethyl esters by electron impact has been investigated by using deuterium labelling techniques, ion kinetic energy and mass analyzed ion kinetic energy spectra. The fragmentation process of [1] is somewhat distinct from those of [2] and [3], due to the interaction of each substituent (that is, an ortho effect).
By taking thermochemical data into account, it is demonstrated that the structure of the intermediate ion, [C8H5O2]+ (m/z 133), generated from [1], is the same as that of the ion at m/z 133 due to loss of a hydrogen atom from the molecular ion of 1,2-benzenedicarbaldehyde, ([4]).View full abstractDownload PDF (333K) -
Shizuo Mohara, Mitsutoshi Tanimoto, Yoshiyuki Kikuchi, Yoko Hasegawa, ...1986 Volume 34 Issue 2 Pages 107-114
Published: 1986
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSMass Spectra of a series of 1,2-dimethoxybenzene derivatives are measured with electron impact ionization, and their characteristic fragmentations are discussed. Analytically useful spectral features are indicated. In particular, 1,2-dimethoxybenzenes substituted with a long alkyl chain were found to display a fragmentation pathway different from those with a short alkyl chain.View full abstractDownload PDF (432K) -
II. Correlations between Mass Spectra and Unsaturations in HydrocarbonesYasuji Koyama, Kogoro Maeda1986 Volume 34 Issue 2 Pages 115-129
Published: 1986
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSCorrelations between m/z values and chemical structures have been examined by using 10-13 peaks higher than 10% to the base peaks for 1813 hydrocarbons extracted from EPA/NIH Mass Spectral Data Base in 4 volumes (1982). It was found that a clear correlation does exist for the structures (m-values) and the base peak m/z values when the hydrocarbons are represented as CnH2n-m. Almost the same correlations were also found for total peaks including the base peak m/z values. By using the correlations obtained, m-value predictions can be made with a very high accuracy about 90 %. Correlations of molecular ion peaks and the structures were also examined, and interesting results were found. Percentages of compounds giving molecular ion peaks higher than 10% to the base peaks are always greater than 60 % to any CnH2n-m compounds with different m-values, except for the case m = -2.View full abstractDownload PDF (1015K) -
Hiroaki Kakinuma, Shigenori Yamamoto, Toshiyuki Nishimuta, Hironori Ya ...1986 Volume 34 Issue 2 Pages 131-138
Published: 1986
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe majority of organic acidurias, as inherited metabolic diseases, are characterized by an acute life-threatening illness in the newborn and infants. A diagnosis cannot be made on the basis of clinical features alone because many of the diseases are accompanied by similar clinical symptoms and signs. Investigation of the urinary organic acids in these patients is therefore important for early diagnosis and effective treatment. The organic acidurias have been diagnosed and chemically characterized primarily by means of gas chromatography-mass spectrometry.
We have developed computer programs for automated identification and quantification of urinary organic acids and for an automated diagnostic system for organic acidurias. We here report on the advantages of this system and our experience in screening for organic acidurias with the use of this system.View full abstractDownload PDF (473K)
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