|Budget Amount *help
¥3,800,000 (Direct Cost : ¥3,800,000)
Fiscal Year 1999 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1998 : ¥2,600,000 (Direct Cost : ¥2,600,000)
In order to clarify the effect of tritium (T) on the functional groups in living systems, the hydrogen-isotope exchange reaction between important functional groups in the systems and T in the environment was quantitatively observed. The following two observations were dynamically carried out in two years : (1) T dispersed from T-labeled polyacrylamide (PAAm(T)) was measured in the constant temperature (and moisture) oven ; (2) the hydrogen-isotope exchange reaction between each kind of unlabeled poly(vinyl alcohol) (PVA) and HTO vapor.
From the above-mentioned, the following eight matters were clarified. (1) When the temperature is high, T from PAAm(T) is great. (2) The form of T-dispersion from PAAm(T) is changed at the moisture of 90 %. (3) In the temperature range of 35〜80 ℃ the T-for-H exchange reaction between HTO vapor and PVA occurred, and in this case, the atoms participating in the reaction are the H atoms in the OH groups in PVA and T atoms in HT0 vapor. (4) The reactivity of
each PVA increases with rising temperature, and decreases with increasing the degree of polymerization. (5) The rate of the decreasing of the rate constant with increasing the degree of polymerization changes at near the degree of polymerization of 1000, and the rate is fairly large under the degree of 1000. (6) Under the degree of polymerization of 1000, the reactivity of PVA is more affected by the effect of the degree of polymerization than by the effect of temperature, and the reactivity is large when the degree of polymerization is small. (7) Over the degree of polymerization of 1000, the reactivity of PVA is affected by both the degree of polymerization and temperature, and the reactivity is large when temperature is high. (8) For the T-for-H exchange reaction in a gas-solid system, the reaction form is unchanged in the range of 35〜80 ℃, and the reactivity at 35 ℃ cannot be neglected.
Moreover the results obtained in this work shows the effect of T on the functional groups (I.e., OH and NHィイD22ィエD2 groups) in living systems, and the effect of T on the systems cannot be neglected. Less