吸收光谱法测定不同价态钚的含量  

Absorption Spectrophotometric Determination of Plutonium in Different Oxidation States

作　　者：伊小伟[1] 党海军[1] 曾斌[1] 林剑锋[1] 

机构地区：[1]西北核技术研究所,西安710024

出　　处：《理化检验（化学分册）》2017年第2期160-164,共5页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：科技部科技基础性工作专项(2015FY110800)

摘　　要：用带有50cm液芯波导毛细管池的光纤光谱仪测定了混合溶液中不同价态钚[Pu(Ⅲ)、Pu(Ⅳ)和Pu(Ⅵ)]的含量。根据Pu(Ⅲ)、Pu(Ⅳ)和Pu(Ⅵ)的吸收光谱特征,分别选择600,474,828nm作为测定这3种离子的波长,并选择在其吸收曲线的波谷区640,492,850nm依次作为参比波长。将在测定波长处所测吸光度减去在参比波长处的吸光度,从而得到上述3种价态钚离子的有效吸光度以扣除基线漂移等所导致的偏差。同时,用单一价态不同浓度的钚离子分别测定其在3个波长处的吸光度绘制标准曲线,并计算得其有效摩尔吸光率。将所测得的有效吸光度及有效摩尔吸光率代入相应的计算公式,即可计算得到上述3种价态钚离子的含量。本方法的测定结果与TTA萃取法所测得的结果比较,两种方法的测定结果在不确定度范围内是一致的。Optical fiber absorption spectrophotometer equipped with 50 cm liquid core waveguide capillary cell was used for determination of plutonium in various oxidation states, i.e. Pu（ III ）, Pu（ IV ） and Pu（ VI ）, in a mixed solution. Based on the spectrometric characteristic of Pu in the 3 oxidation states, 600, 474, 828 nm were chosen as the wavelengths for measuring the absorbances of Pu（ III ）, Pu（ IV ） and Pu（ VI ） respectively. To eliminate deviations due to drift of baselines in measurements of absorbances, values of absorbances were measured at the reference wavelengths at 640, 492, 850 nm, which were selected from the trough of the respective measuring wavelengths, and substracted from their values of absorbance of Pu（ III ）, Pu（IV） and Pu（VI） respectively, to obtain their valid values of absorbance. Simultaneously, standard curves and valid values of molar absorptivities were determined with Pu standard solutions of single oxidation state by measuring the absorbances at the related wavelengths. The values obtained were substituted into the given formulas and contents of Pu（ III ）, Pu（ IV ） and Pu（ VI ） in the mixture were calculated. The results obtained were checked by the TTA extraction method, and consistency within the range of uncertainty between the results of the 2 methods was attained.

关 键 词：吸收光谱法 钚 价态 

分 类 号：O657.31[理学—分析化学]