RADIOISOTOPES

Determination of Short Life Nuclides with Time Interval Analytical Technique

Yasuhiro UEZU, Tetsuo HASHIMOTO

2002 Volume 51 Issue 6 Pages 229-236
Published: June 15, 2002
Released on J-STAGE: March 01, 2011

DOIhttps://doi.org/10.3769/radioisotopes.51.229

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A new determination method for short life nuclides with linking technique between time interval pulse distribution and energy information was developed In this system, alpha pulses within 100 us time resolution were sent to multi channel analyzer and timer simultaneously. After measurement, energy and time interval information is loaded from hard disk and a combination of time interval and energy distributions are sorted to determine short half-life nuclides.
Besides, this system also has a subtraction function within short time intervals. Thus, this system is able to determine for long half-life nuclides such as Pu or Am in dust samples by subtraction of backgrounds as progenies of Rn or Tn.

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Development of a New Non-dispersed Infrared Analyzer for ¹³C Breath Test

Kazuhiko TAKATORI, Takeshi CHIYODA, Toshihiro ISHII, Masao YAMAZAKI, M ...

2002 Volume 51 Issue 6 Pages 237-243
Published: June 15, 2002
Released on J-STAGE: March 01, 2011

DOIhttps://doi.org/10.3769/radioisotopes.51.237

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A new small infrared analyzer for ¹³C breath tests was developed by using a Golay cell as a nondispersed detector. This analyzer, equipped with an automatic sampling system, does not require a thermoregulator and liquid nitrogen. By the device of the optical system and the piping, the measurement became possible in the amount of one sample of 100mL. Moreover, the measurement time of a one-set sample, which consists of two samples, was able to be carried out within 8 min. The reproducibility was S.D. ≤ Δ 0.8 ‰, and the linearity of Δ ‰ value measured by this analyzer was good as compared with IRMS In measurement of breath samples, the correlation between Δ ‰ value measured by this analyzer and those measured by MS was also good, when CO₂ concentration is more than 2.5%.

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Effect of the Number of Methylene Groups in Aliphatic Dicarboxylic Acid on the Reactivity of the Material (Use of T-for-H Exchange Reaction)

Hiroshi IMAIZUMI, Takehisa KATO, Dongyu ZHAO, Naoki KANO

2002 Volume 51 Issue 6 Pages 244-248
Published: June 15, 2002
Released on J-STAGE: December 16, 2010

DOIhttps://doi.org/10.3769/radioisotopes.51.244

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Hydrogen-isotope exchange reaction (T-for-H exchange reaction) between HTO vapor and aliphatic dicarboxylic acid having different number of methylene groups with each other has been observed at 50°C. Consequently, the quantitative relation was obtained between the reaction time and the increase of the activity of aliphatic dicarboxylic acid. The reaction was dynamically analyzed with both the A″-McKay plot method and data obtained.
As to aliphatic dicarboxylic acids, the following two matters have been consequently found : (1) as the reactivity of each material decreases with increasing the number of methylene groups in the material, the effect of the number of methylene groups per molecule on the reactivity of the material can be quantitatively evaluated, (2) using the A″-McKay plot method, the reactivity of solid organic compounds can be evaluated, nondestructively.

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Stable Hydrogen Isotope Analysis of Individual Biomolecules and Its Application to Geochemistry and Environmental Science

Hiroshi NAKAMURA, Yoshito CHIKARAISHI

2002 Volume 51 Issue 6 Pages 249-250
Published: June 15, 2002
Released on J-STAGE: July 21, 2010

DOIhttps://doi.org/10.3769/radioisotopes.51.249

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