Abstract:
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)
2NH
+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)
2NH
+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)
2NH
+2 in total amine ions decreases, while the proportion of NH
+4 in total amine ions increases.