CRM铀微粒的FT-TIMS分析方法研究

在核保障环境取样分析中，对含铀单微粒进行元素和同位素分析是十分重要的。裂变径迹(FT)与热表面电离质谱(TIMS)联用是一种公认的微粒同位素分析技术路线。本文报道了一种改进的FT-TIMS分析方法，方法分为3步：将微粒分散到火棉胶、乙酸异戊酯混合溶液中，然后将溶液平铺在光滑、洁净的玻璃表面上，干燥后形成具有一定厚度的薄膜；将薄膜放入反应堆进行辐照，取出薄膜后将其蚀刻，通过显微镜寻找以及定位铀微粒并将含有铀微粒的部分薄膜分割出来；将分割出来的含有铀微粒的薄膜制样后，用TIMS进行同位素分析。结果表明，这种方法可实现铀微粒的准确定位，有效地解决了铀微粒定位误差问题；同时避免了在微粒转移过程中可能发生的微粒丢失情况；对于CRMU200微粒，²³⁵U/²³⁸U测量值与参考值偏差在2%以内。

Analysis of Single Uranium Particle by FT-TIMS

In the safeguards environmental sampling,analyzing isotopic ratio of single uranium-bearing particle in swipe samples was very important.For this purpose,fission track(FT) technique was successfully applied in combination with thermal ionization mass spectrometry(TIMS).An improved FT-TIMS analysis method was developed.The particle was suspended in the solution of collodion commixed with isoamyl acetate and then spread onto a glass surface,and the solution was dried to form a polycarbonate film.After irradia...