79SeAMS测量实验室标准中79Se/78Se比值

Using liquid scintillation counting (LSC) to determine the ratio of ⁷⁹Se/⁷⁸Se in the irradiated sample was reported. Firstly, the γ and β spectrum of irradiated sample was measured to find out the interferefering nuclide. Then, the irradiated sample was heated up to remove the interferefering nuclide from the sample as much as possible. At last, the activity ⁷⁹Se was determined by LSC, and the ratio of ⁷⁹Se/⁷⁸Se was determined to be (5.44±0.23)×10^－5. It provides reliable standard sample for AMS measurement.     

79Se-AMS生物示踪方法学的研究

由于具有放射性非常弱以及对生物组织甚至是细胞无损伤的特点，⁷⁹Se是对硒元素进行长期无损伤生命科学研究的理想示踪核素。⁷⁹Se示踪方法学的建立对于硒的生命科学与生物医学研究将具有十分特殊的意义。加速器质谱测量⁷⁹Se（⁷⁹Se-AMS）的生物示踪方法学具有高灵敏度，高准确性以及高精度等特点。通过采用⁷⁹Se-AMS方法对亚毒性剂量的硒代谢过程进行研究，建立了⁷⁹Se-AMS生物示踪方法学，重点探索了生物示踪样品的制备流程，化学处理以及样品测量过程。采用分子负离子的引出形式以及四阳极双栅电离室对⁷⁹Se和⁷⁹Br两种同量异位素进行鉴别，从而记录实际样品中⁷⁹Se的原子个数。实验建立了亚毒性剂量硒在Wistar大鼠肾脏内的代谢曲线，为生命科学以及生物医学领域提供了新的测量方法与手段，也为AMS的应用开拓了新的领域。     

加速器质谱测量93Zr的刻度研究

A method of determination for ⁹³Zr/⁹²Zr ratio by multi-collector inductively plasma mass spectrometry (MC-ICP-MS) was described in this paper. A ⁹³Zr/⁹²Zr ratio of (2.75±0.07)×10^－5 was obtained in the original sample for AMS measurement and its relative standard error was 2.5%. Considered the contribute of above-thermal neutron, a calculated ⁹³Zr/⁹²Zr ratio of 2.56×10^－5 was obtained and it was according with measurement of the result. The results showed that it can be used for AMS measurement standards sample preparation. A series 93Zr standards sample for AMS measurement were diluted by irradiated sample with enriched 92Zr.     

长寿命裂变产物126Sn活度和原子数的γ能谱法测定

By using HPGe γ-ray spectrometry, the activity of the long-lived fission product ¹²⁶Sn was measured. The number of ¹²⁶Sn atoms and the isotopic abundance of 126Sn/Sn were calculated based on the half-life value of 2.35×10⁵ a. The result of the isotopic abundance, (1.037±0.044)×10^－8, is consistent with the results measured by the accelerator mass spectrometry (AMS) within uncertainty limits, that confirms our procedures in the measurement of ¹²⁶Sn by AMS and lays a foundation for the AMS measurement of ¹²⁶Sn at much lower levels.     

多接收电感耦合等离子体质谱测定182Hf/180Hf的方法研究

¹⁸²Hf is an important radionuclide for nuclear research and supernova explosions. The reference material of ¹⁸²Hf/¹⁸⁰Hf is especially important, but not yet available. Considering the demands of nuclear science research an development, a method was developed to measure the ratio of ¹⁸²Hf/¹⁸⁰Hf with high-precision by using multi-collector inductively plasma mass spectrometry (MC-ICP-MS). The operating parameters of MC-ICP-MS were optimized. Isobar interference and mass bias were studied. The measurement result of the ratio of ¹⁸²Hf/¹⁸⁰Hf was obtained based on deducting the interference of isobaric ¹⁸²W.     

同位素稀释-热电离质谱法测定乏燃料中裂变产物121Sn和126Sn

乏燃料样品基体复杂、具有放射性,裂变产物锡含量低,难以准确测定。本研究以天然锡（Sn）标准溶液为稀释剂,采用同位素稀释-热电离质谱法测定乏燃料元件中¹²¹Sn和¹²⁶Sn裂变产物的含量。热电离质谱测量时采用硅胶 锡 磷酸涂样,优化选择电离带升温速率和温度保持时间,利用阻滞电位四极杆（RPQ）跳峰对13个质量数信号进行数据采集,有效扣除了Te、Sb、CaPO₃⁺多个同量异位素的干扰,获得了ng/g级Sn的含量及同位素丰度测量数据。乏燃料元件中¹²¹Sn和¹²⁶Sn的质量浓度分别为5.5、230.5 ng/g,测量不确定度分别为4.2%和1.4%（k=2）。     

ICP-MS测定辐射环境监测样品中238U和232Th比活度实践

Monitoring of ²³⁸U and ²³²Th in radiation environmental samples including water and biota was requested by the related international and national safety guides and standards. Inductively coupled plasma mass spectrometry (ICP-MS) was applicable to determination of ²³⁸U, ²³²Th in such samples with a high sensitivity and working efficiency. Some practical aspects are presented.     

利用多接收器电感耦合等离子体质谱法精确测定天然岩石样品中的铼含量

利用多接收器电感耦合等离子体质谱（MC-ICPMS）精确测定了天然岩石样品的铼含量。在膜除溶雾化进样条件下,铼测试样品中加入铱标准溶液,通过在线监控铱同位素的质量分馏行为来校正铼同位素的质量分馏。实验发现,铼和铱的质量分馏系数（f_Re和 f_Ir）是不相等的,如果认为 f_Re=f_Ir,将会导致¹⁸⁷Re/¹⁸⁵Re同位素比值偏低,但是 f_Re/f_Ir比值固定不变,这样可以通过已知的 f_Ir 计算出 f_Re,从而得到准确的¹⁸⁷Re/¹⁸⁵Re同位素比值。本工作利用这种经验的质量分馏校正方法,精确的测定出天然铼标准样品的¹⁸⁷Re/¹⁸⁵Re同位素比值为1.674 3±0.000 1（2σ, n=25）,该结果与国际纯粹与应用化学委员会（IUPAC）推荐值（1.674 0±0.001 1）以及与N-TIMS测定值（1.675 ±0.001 4）在误差范围内一致。而且,采用该经验的质量分馏校正方法测得的天然铼标准样品的¹⁸⁷Re/¹⁸⁵Re同位素比值与采用 f_Re=f_Ir 校正结果相比,准确度和外部重现性都明显提高。最后采用该方法准确测定出了天然岩石中Re含量,该结果与N-TIMS测定结果吻合。     

葡萄酒中锶的分离及MC-ICP-MS测量

Isotopes can be applied to food geographical origin traceability as “fingerprint”. The radioactive disintegration of Sr in different samples leads to variation of ⁸⁷Sr /⁸⁶Sr in nature. Sr in wine comes from soils, rocks and water in vine yard, ⁸⁷Sr /⁸⁶Sr can give much information about the geographical origin of wine. This paper describes in details the separation procedure by Sr-resin and determination by MC-ICP-MS.     

同质异位素干扰下同位素比的ETV-ICP-MS测定

A self-made electrothermal vaporization (ETV) device was used to solve the isobaric interference in the isotope ratio analysis by ICP-MS. As a sampling method used in ICP-MS, ETV was used about twenty years and performed many merits. One of these merits is that it can separate the matrix of sample online according to the different evaporation rate of different element or compound on the filament of ETV. By this character, the isotope ratio of ¹⁷⁶Lu/¹⁷⁵Lu , as a example, was determined under the isobaric interference of ¹⁷⁶Yb by ETV-ICP-MS .