Abstract Thermal ionization mass spectrometry (TIMS)-based isotopic analysis of various amounts of uranium was performed to experimentally evaluate three detection methods: multi-dynamic, dynamic, and static. The analytical performances of the detection methods in terms of accuracy, precision, and measurement uncertainty were not significantly different for the analysis of 1 ng and 100 pg of uranium, whereas using ion counters for detecting 238U+ signal intensity slightly enhanced the performance for analyzing 30 pg of uranium. The static detection method improves the analysis performance for 5 pg and 1 pg of uranium due to the higher detection sensitivity of ion counters than faraday cups, elimination of ion signal drift, and increased number of valid data sets in a measurement. The experimental evaluation of the detection methods provides a basis for optimizing the detector configuration of TIMS in terms of the amount of uranium in samples. The uranium isotope ratios in microparticles measured by the static method agreed well with the certified values; this verified the applicability of the static detection method to particle analysis of environmental samples required for nuclear safeguards.

中文翻译：

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超痕量铀同位素分析热电离质谱检测方法的实验评价

摘要 对不同量的铀进行了基于热电离质谱 (TIMS) 的同位素分析，以通过实验评估三种检测方法：多动态、动态和静态。对于 1 ng 和 100 pg 铀的分析，检测方法在准确度、精密度和测量不确定度方面的分析性能没有显着差异，而使用离子计数器检测 238U+ 信号强度略微提高了分析 30 pg 的性能铀。由于离子计数器的检测灵敏度高于法拉第杯、消除了离子信号漂移以及增加了测量中有效数据集的数量，因此静态检测方法提高了 5 pg 和 1 pg 铀的分析性能。检测方法的实验评估为根据样品中铀的含量优化 TIMS 的检测器配置提供了基础。静态法测得的微粒中铀同位素比值与标准值吻合良好；这证实了静态探测方法适用于核保障所需的环境样本的粒子分析。