摘要
用离子色谱仪检测了在常温、稀硝酸溶液中相对过量的二甲基羟胺(DMHAN)与Fe^(3+)、Ce^(4+)和Pu^(4+)反应生成的胺类离子产物。研究表明:DMHAN与Fe^(3+)、Ce^(4+)和Pu^(4+)均可以在酸性条件下生成一定量的胺类离子,包括(CH_(3))_(2)NH_(2)^(+)、NH_(4)^(+)和CH 3NH_(3)^(+)。其反应机理为:DMHAN与Fe^(3+)、Ce^(4+)和Pu^(4+)反应时,因DMHAN中的N原子为-1价,它在酸性溶液中既可以显氧化性又可显还原性,于是部分DMHAN被还原为(CH_(3))_(2)NH_(2)^(+),其中部分(CH_(3))_(2)NH_(2)^(+)又进一步转为CH 3NH_(3)^(+)、NH_(4)^(+)。随着Fe^(3+)、Pu^(4+)和Ce^(4+)的氧化还原电位的增加,DMHAN转变为胺类离子的比例增加;(CH_(3))_(2)NH_(2)^(+)占总胺类离子的比例减小,NH_(4)^(+)占总胺类离子的比例增大。这使得在各反应中生成的NH_(4)^(+)、CH 3NH_(3)^(+)、(CH_(3))_(2)NH_(2)^(+)的比例也有所不同。
The ammonium ions produced by the reactions of relatively excessive dimethylhydroxylamine(DMHAN)with Fe^(3+),Ce^(4+)and Pu^(4+)in dilute nitric acid solutions at room temperature were determined by ion chromatographic method.The results show that the reactions between DMHAN and Fe^(3+),Ce^(4+)and Pu^(4+)all produce a certain amount of ammonium ramifications under acidic conditions,which includes(CH_(3))_(2)NH_(2)^(+),NH_(4)^(+) and CH 3NH_(3)^(+).The reaction mechanism is as follows.When DMHAN reacts with Fe^(3+),Ce^(4+)and Pu^(4+)respectively,it can be oxidized and reduced simultaneously in the acidic solution for the-1 valence of N atom in DMHAN.Then part of DMHAN is reduced to(CH_(3))_(2)NH_(2)^(+),and it is further converted into NH_(4)^(+) and CH 3NH_(3)^(+) partly.With the increase of redox potential of Fe^(3+),Pu^(4+)and Ce^(4+),the conversion ratio of DMHAN into amine ions increases and the proportion of(CH_(3))_(2)NH_(2)^(+) in total amine ions decreases,while the proportion of NH_(4)^(+) in total amine ions increases.
作者
李传博
王博
娄付燕
陈辉
杨舒茗
李想
LI Chuan-bo;WANG Bo;LOU Fu-yan;CHEN Hui;YANG Shu-ming;LI Xiang(China Institute of Atomic Energy,P.O.Box 275(26),Beijing 102413,China)
出处
《核化学与放射化学》
CAS
CSCD
北大核心
2022年第6期597-603,I0003,共8页
Journal of Nuclear and Radiochemistry
