State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Xi'an AMS Center, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; China Institute of Radiation Protection, Taiyuan, China.
State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Xi'an AMS Center, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
Talanta. 2018 Sep 1;187:357-364. doi: 10.1016/j.talanta.2018.05.051. Epub 2018 May 21.
In order to measure trace plutonium and its isotopes ratio (Pu/Pu) in environmental samples with a high uranium, an analytical method was developed using radiochemical separation for separation of plutonium from matrix and interfering elements including most of uranium and ICP-MS for measurement of plutonium isotopes. A novel measurement method was established for extensively removing the isobaric interference from uranium (UH and UH) and tailing of U, but significantly improving the measurement sensitivity of plutonium isotopes by employing NH/He as collision/reaction cell gases and MS/MS system in the triple quadrupole ICP-MS instrument. The results show that removal efficiency of uranium interference was improved by more than 15 times, and the sensitivity of plutonium isotopes was increased by a factor of more than 3 compared to the conventional ICP-MS. The mechanism on the effective suppress of U interference for Pu measurement using NH-He reaction gases was explored to be the formation of UNH and UNH in the reactions of UH and U with NH, while no reaction between NH and Pu. The detection limits of this method were estimated to be 0.55 fg mL for Pu, 0.09 fg mL for Pu. The analytical precision and accuracy of the method for Pu isotopes concentration and Pu/Pu atomic ratio were evaluated by analysis of sediment reference materials (IAEA-385 and IAEA-412) with different levels of plutonium and uranium. The developed method were successfully applied to determine Pu and Pu concentrations and Pu/Pu atomic ratios in soil samples collected in coastal areas of eastern China.
为了测量高铀环境样品中的痕量钚及其同位素比值（Pu/Pu），开发了一种分析方法，该方法使用放射化学分离法从基体和干扰元素（包括大部分铀）中分离钚，以及使用 ICP-MS 测量钚同位素。通过在三重四极杆 ICP-MS 仪器中采用 NH/He 作为碰撞/反应池气体和 MS/MS 系统，建立了一种新的测量方法，可有效去除铀（UH 和 UH）的同位数干扰和铀的尾部，同时显著提高钚同位素的测量灵敏度。结果表明，铀干扰的去除效率提高了 15 倍以上，与传统的 ICP-MS 相比，钚同位素的灵敏度提高了 3 倍以上。采用 NH-He 反应气体有效抑制 Pu 测量中 U 干扰的机制被探索为 UH 和 U 与 NH 反应生成 UNH 和 UNH，而 NH 与 Pu 之间没有反应。该方法的检测限估计为 0.55 fg/mL 的 Pu 和 0.09 fg/mL 的 Pu。通过分析具有不同 Pu 和 U 水平的沉积物参考物质（IAEA-385 和 IAEA-412），评估了该方法对 Pu 同位素浓度和 Pu/Pu 原子比的分析精密度和准确度。该方法成功应用于测定中国东部沿海地区土壤样品中的 Pu 和 Pu 浓度以及 Pu/Pu 原子比。
