【摘要】 <正> 制备高比度氚标记化合物的方法主要有催化加氚法,催化卤-氚交换法和催化氢-氚同位素交换法。催化剂本身并不参加化学反应,只在其表面吸附氚气从气相进入液相或固相,改变反应速度,提高标记物的比度。常用的催化剂有钯、铂、铑等过渡金属元素。李志敏的工作证明钯-碳催化剂在催化加氚反应中不仅有催化作用,而且对氢-氚体系而言,还有明显的分离作用。更多还原

【Abstract】 Experimental results of catalyzed-labelling of tetramethylpyrazine by means of Pt-black, Pd-black and RhCl3 are obtained It is found that efficiency of the hydrogen-tritium isotopes exchange decreases in the order of Pt- blaek> RhCl3>Pd-black, but that of the 3H-H isotopes exchange increases in the order of Pt-black<RhCl3<Pd-black under the same conditions.更多还原