水样中Pu、Np、Am和Cm的联合快速分析方法

环境监测、辐射防护、核取证和核应急等领域对环境和生物样品中²³⁸Pu、²³⁹Pu、²⁴⁰Pu、²⁴¹Pu、²³⁷Np、²⁴¹Am、²⁴³Cm和²⁴⁴Cm测定的需求日渐增大。本研究提出一个自上而下串联TEVA树脂、UTEVA树脂和DGA树脂的联合、快速、可靠、可批量操作的分析方法，该方法首先通过水合氧化钛（HTO）共沉淀将待测核素从样品基质中分离，其后使用串联层析柱中的TEVA树脂柱分离纯化Pu与Np，DGA层析柱分离纯化Am与Cm。对于α放射性核素，通过CeF₃微沉淀法制备薄层α测量源，使用高分辨率α谱仪分别测量^239+240Pu、²³⁸Pu、²³⁷Np、²⁴¹Am与^243+244Cm；对于β放射性核素²⁴¹Pu，使用液体闪烁计数器测量。²³⁶Pu和²³⁴Am示踪表明该流程的化学回收率大于80%，加标实验结果表明期望值与测量值相吻合，证明了该方法的高可信度及稳定性。α谱仪测量48 h，最小可探测活度²⁴¹Am为0.40 mBq，^243+244Cm为0.33 mBq，²³⁸Pu为0.72 mBq，^239+240Pu为0.44 mBq，²³⁷Np为0.72 mBq。液闪计数器测量1 800 s，²⁴¹Pu的最小可探测活度为0.17 Bq。使用12孔真空盒同时制备12个样品，可加快制样时间，批次制样时间小于3 h，极大地降低了样品的使用量、制备时间和分析成本。

Rapid and Simultaneous Separation and Determination of Pu,Np, Am and Cm in Water Samples

There is a growing demand for the determination of Pu, Np, Am and Cm in environmental and biological samples in fields of environmental radioactivity monitoring, radiation protection, nuclear forensics and nuclear emergency preparedness. A reliable and efficient method based on TEVA+UTEVA+DGA chromatography separation has been developed for simultaneous determination of these radionuclides in water samples. Hydrous titanium oxide(HTO) was used to pre-concentrate the analyte nuclides, then the TEVA column of stacked extraction chromatographic columns was used to retain Pu and Np, and Am, Cm were separated together with the DGA resin. Alpha emitting isotopes ^239+240Pu, ²³⁸Pu, ²³⁷Np,²⁴¹Am, ^243+244Cm were determined by alpha spectrometry after CeF₃ micro precipitation, while beta emitters²⁴¹Pu was determined by liquid scintillation(LS) counter. The overall recoveries of these nuclides for the entire procedure indicated by ²³⁶Pu and ²³⁴Am are higher than 80%. Spiked samples along were analyzed to evaluate the performance of the method. The measured results agree very well with the expected values for all the spike samples. With 48 h of counting, the minimal detectable activities(MDAs) are found to be 0.40 mBq for²⁴¹Am, 0.33 mBq for ^243+244Cm, 0.72 mBq for ²³⁸Pu, 0.44 mBq for ^239+240Pu, 0.72 mBq for ²³⁷Np by alpha spectrometry; and 0.17 Bq for²⁴¹Pu with a counting time of 1 800 s by liquid scintillation counter. Using vacuum box technique for batch processing, it can reduce the sample preparation time. The time required for analysis of a batch of 12 samples is less than 3 h. This method can provide high sample analysis throughput, quick analysis turn around time for cost and time saving.