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Volume 40 (1992)
- Issue 6 Pages 283-
- Issue 5 Pages 241-
- Issue 4 Pages 217-
- Issue 3 Pages 159-
- Issue 2 Pages 87-
- Issue 1 Pages 1-
Volume 40, Issue 3
Displaying 1-3 of 3 articles from this issue
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REGULAR PAPERS
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Hidetoshi FUJIWARA, Ichizo OKABAYASHI1992 Volume 40 Issue 3 Pages 159-163
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSThe mass spectra of indolizidin-8-ol derivatives (1-6) were measured by electron impact ionization.
The characteristic fragment ions were observed in the mass spectra of the indolizidin-8-ol derivatives at m/z 154, m/z 140, m/z 136, m/z 110, m/z 97, m/z 96, m/z 84, m/z 70, m/z 69, and m/z 55.
The peak intensities at M+· and m/z 154 in the mass spectra at 70 ev of the epimers of indolizidin-8-ol derivatives show little difference, but careful examination of the spectra at 70 eV and 20 eV enables distinction between two epimers. The difference between alkyl and phenyl substituents can be recognized by the peak intensities at m/z 154, m/z 140, and m/z 136.View full abstractDownload PDF (313K) -
Akihiro SHIBATA, Yoshio IIDA, Tokishi HAYASHI, Natsuko OTSUKI1992 Volume 40 Issue 3 Pages 165-171
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSA method for the determination of phenylpyruvic acid (PPA) in human urine and plasma by gas chromatography/negative ion chemical ionization (NCI) mass spegtrometry was developed, in order to study its variation in concentration against time in the human body using an isotope labelled analogue. After 100 μl of urine and plasma sample spiked with [13C6]-PPA internal standard was purified with a hydrazide gel column, it was converted into the stable quinoxalinol derivative with 4,5-diamino-o-phenylendiamine in acidic solution, followed by conversion into the pentafluorobenzyl (PFB) derivative. The NCI mass spectra of the PPA-quinoxalinol-PFB derivative gave a base peak at m/z 263 (M-PFB)- with methane reagent gas. This ion was used for selected ion monitoring (SIM) in high resolution (R= 8,000) mode, with perfluorokerosene (PFK) used as a lock mass. The determination limit of this method was 1.0 pg. The PPA concentrations in urine and plasma from healthy persons were found to be 0.272±0.159 nmol/mg creatinine and 0.232±0.078 nmol/ml (n =12) with repeatability (R.S.D) of 3.3% and 4.2% (n = 5), respectively. The presence of keto- and enol-isomers in PPA-quinoxalinol derivatives were also confirmed from their IR spectra. The proposed method can be used for measuring the metabolism of PPA in vivo by labelled compound dosage.View full abstractDownload PDF (456K)
TECHNICAL REPORT
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Hisashi MORIKAWA, Yoshinori UWAMINO, Toshio ISHIZUKA1992 Volume 40 Issue 3 Pages 173-180
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSThis paper reports on the extreme sample bias shift (ESBS) method for the analysis of insulating specimens in SIMS. The change of surface potential on the specimen caused by charge buildup was effectively compensated by providing the extremely high sample bias in case of oxygen negative primary ion bombardment and positive secondary ion detection. We precisely studied the influence of the analytical point on the sample upon the secondary ion intensities and energy distributions. Furthermore, spectral interference and reproducibility of secondary ion intensity ratios were discussed for quantitive analysis. It was found that at the center of the sample, the maximum and stable secondary ion intensities were obtained and a 90 V offset of the sample bias offered the reasonable compromise between analytical sensitivity and reproducibility with the effective suppression of spectral interference. The ESBS method allows the high sensitive analysis of insulating specimens without both any special sample pretreatment and costly modification of the SIMS instrument.View full abstractDownload PDF (612K)
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