Purex流程中二甲基羟胺与甲基肼的分析

摘要

研究了在测定1BP中的N,N-甲基羟胺(DMHAN)和甲基肼(MMH)的浓度之前用TODGA将其中的Pu(Ⅲ)萃取出来；并基于所发现的在室温下pH为2.0～5.5时,Fe3+只与DMHAN反应而不与稀的MMH发生反应;以及在室温下pH为0～5.5时,稀的I2溶液只与MMH发生反应而不与稀的DMHAN反应；分别建立了用Fe3+/邻菲罗琳-分光光度法测定1BP萃余液中DMHAN的浓度,相对偏差小于1.0％,检测下限为3.00×10-6 mol/L;用I2溶液褪色-分光光度法测定了其中的MMH的浓度,相对偏差小于1.0％,检测下限为3.00×10-5 mol/L.并考察了反应时间、甲醇、甲醛和酸度等对结果的影响.该方法不仅适用于测定1BP中DMHAN和MMH的浓度,也适用于1BX、2BX和2BP中.%The extraction of Pu( Ⅲ) with TODGA from IBP solution prior to the determination of N, N-dimethylhydroxylamine (DMHAN) and methylhydrazine (MMH) in it was studied and excellent removal was observed. It was found that Fe3+ could react with DMHAN but did not react with MMH in the pH range 2. 0-5. 5 at room temperature. It was also found that dilute I2 solution reacted only with MMH but not with dilute DMHAN in the pH range 0-5. 5 at room temperature. Based on these findings the determination of DMHAN with Fe3+/1, 10-phenanthroline spectrophotometry? And the determination of MMH by iodine fading spectrophotometry were developed. Their detection limits were found to be 3. 00×10-6 mol/L and 3. 00 × 10~5 mol/L, respectively. Their analytical errors were estimated lower than 1. 0%. The influence of reaction time? Acidity? And the existence of metha-nol or formaldehyde on the determination was examined. These methods could also be used to analyze DMHAN and MMH in 1BX, 2BX, and 2BP solutions.