聚丙烯纤维滤材气溶胶样品的浸取-灰化-消解前处理方法

在《全面禁止核试验条约》(CTBT)体系的放射性核素监测中,需要对气溶胶可疑样品进行前处理,以便进行详细分析。这类气溶胶样品基体质量大,待测元素多且化学性质差异大,单用某一种前处理方法难以保证回收率。本工作提出了浸取-灰化-消解联用的方法,即微波密闭浸取易挥发元素、灰化除去滤材基体、再用微波密闭消解溶解难溶元素的方法。实验用聚丙烯纤维滤材制备了模拟样品,以铯、铈和锆为代表研究了浸取压力、功率、时间、灰化条件以及消解酸种类和用量等条件对回收率的影响。实验结果表明:在最佳条件下,外加于气溶胶样品的铯、铈和锆可以定量回收。

Extraction-Ashing-Digestion Pretreatment Method for Polypropylene Fibrous Filter Collected Aerosol Samples

Suspicious aerosol samples need to be pretreated for detailed analysis in radionuclide monitoring proposed by the Comprehensive Nuclear-Test-Ban Treaty(CTBT).These samples are quite different from common aerosol samples since their filter matrix are massive and the number of analysed elements is large and their contents are very different.As a result,any single pretreatment method is not effective for recovering all radionuclides.A novel extraction-ashing-digestion method is proposed in this paper,including microwave extraction of volatilizable radionuclides,ashing of filter matrix and microwave digestion of difficultly soluble radionuclides.The spiked samples with polypropylene fibrous filter matrix were prepared.Natural abundance elements cesium,cerium and zirconium were selected as trace elements to validate the method.The recoveries under varied conditions such as pressure,power,duration time of microwave extraction,ashing temperature and time,as well as composition and concentration of microwave digestion reagents,were studied experimentally.The results show that cesium,cerium and zirconium in samples can be recovered completely under the optimum conditions.