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.     

光学玻璃105-1013泊粘度的测定

光学玻璃生产制造的全过程中,玻璃的澄清、搅拌、出炉、成型都与玻璃的粘度有关。     

53Mn/55Mn实验室标准样品制备及加速器质谱测量

宇宙成因核素⁵³Mn是一种非常理想的地质定年工具。近年来,随着加速器质谱（AMS）技术的不断发展,⁵³Mn的高灵敏测量成为可能。本工作介绍了⁵³Mn/⁵⁵Mn的系列实验室标准样品的制备以及AMS测量,结果表明：⁵³Mn/⁵⁵Mn的测量值与标称值在误差范围内比较吻合且呈现良好的线性关系,中国原子能科学研究院的AMS系统对⁵³Mn的测量灵敏度可以达到10^-14。     

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）。     

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。     

H2O2浸泡对无机碳酸盐沉积11B的影响

Pretreatments were used to remove organic “contaminant” material prior to isotopic analyses of coral skeletal samples. We conducted one experiments to test the pretreatment effect of 30% hydrogen peroxide (H₂O₂) on the boron isotopic composition of inorganic carbonate. The experimental results indicate that H₂O₂ can change the boron isotopic composition.     

32Si半衰期的加速器质谱测量方法研究

³²Si是宇宙射线与空气中的Ar通过散裂反应产生的长寿命放射性核素,利用³²Si可以开展广泛的应用研究。然而作为放射性核素关键数据的³²Si半衰期数据仍然存在较大的偏差,这在很大程度上阻碍了³²Si的应用。本工作利用中国原子能科学研究院的加速器质谱系统开展了³²Si半衰期的测量。通过反应堆辐照Mg₂P₂O₇生产³²Si并制备出用于加速器质谱测量和活度测量的样品;利用加速器质谱技术进行了³²Si/Si绝对比值的测定;通过液闪对样品进行了放射性活度测量,从而实现了³²Si半衰期的测定,得到³²Si的半衰期值为(182±16)a。     

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法测定79Se

The analysis of ⁷⁹Se in high radioactive waste using a multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) is described, Hexapole collision cell was used to remove argide-based interferences, which have always presented a problem to the measurement of certain elements, such as Ca, Cr, Fe, and Se. ⁷⁸SeH was deducted from the measurement of ⁷⁹Se.     

EA-MS测试过程中添加助燃剂的影响效应研究

利用元素分析-质谱仪(EA-MS)联用系统,探讨对高C/N植物样品测试过程中添加助燃剂对样品氮同位素比值、氮含量和仪器本底的影响。在植物样品中添加CuO或者V₂O₅,测定的氮同位素组成结果表明：添加助燃剂导致样品测试的结果偏差更小,这与测试过程中植物样品能够完全燃烧有关;添加助燃剂使测试的氮含量高于不添加助燃剂的情况,同时仪器本底也能迅速降低,说明助燃剂的添加有助于样品在瞬间燃烧,因此使测试结果更为精确;不同助燃剂的添加对植物氮同位素比值结果的影响程度不同,与不添加助燃剂的情况相比,CuO的添加使得同位素比值偏正,而V₂O₅的添加结果不具有规律性;在样品中添加CuO助燃剂（和植物样品以4∶1的质量比混合）,样品测试的同位素值偏差最小,测试结果也更加可信,样品本底可以达到连续做样而不影响测定下一样品的氮同位素组成。该方法简单、有效、投入较少,可以用于难以反应的样品分析中。     

超高压液相色谱-质谱联用法研究L,L-双半胱氨酸的氧化反应动力学

L,L-ethylene dicysteine(L,L-EC) is a diaminodithiol(N₂S₂) ligand used in nuclear medicine for the preparation of ^99mTc-L,L-EC, a tracer agent for renal function studies. The dithiol groups of L,L-EC are easily oxidized and form the corresponding disulfide. In this paper, the dynamic oxidation process of L,L-EC was studied by ultra-performance liquid chromatography tandem mass spectrometry(UPLC/MS/MS) in multiple reaction monitoring(MRM) mode. The kinetic experiments were conducted at three different temperatures. The reaction order and the rate constants for the transformation of L,L-EC were calculated using kinetic data under pseudo-first-order reaction conditions. The activation energy of the oxidation of L,L-EC was calculated by an Arrhenius graph.     

锂分子的TIMS探测

After the determination for lithium isotope abundant was accomplished, the electrical current on the ionization and vaporization strip is increased and the big current of lithium ion is kept. The ionic current of Li2 is inspected by magnetic field scanning and the ionic current of Li₂ is reality, but ¹²Li₂^＋、¹³Li₂^＋、14Li₂^＋ are not separated and they compose the widest peak form.     

EGC/GC和EGCG/GCG的ESI-IT-TOF质谱裂解规律研究

利用离子阱飞行时间质谱仪的高质量准确度、高分辨率、多级测定的性能，对表没食子儿茶素/没食子儿茶素(EGC/GC)和表没食子儿茶素没食子酸酯/没食子儿茶素没食子酸酯(EGCG/GCG)（二组对映异构体）的质谱裂解规律进行了研究，并利用氢/氘交换的方法对其裂解方式进行了确证。研究发现，儿茶素对映异构体间具有相同的质谱裂解途径，即使在多级质谱中也无明显区别，仅碎片离子的相对丰度存在差异。二级质谱中， EGC/GC在B环丢失CO₂，且其A, B环都可失去C₂H₂O。^1,4A^-、^1,3A^-、^1,2A^- 和[M-H-B环]^-四个碎片离子是EGC/GC的特征性离子，通过此四离子质荷比的变化，可推测A环上的取代情况。因EGCG/GCG的结构上都含有没食子酸的取代基，在二级质谱中均可见m/z 169的特征性离子峰，此离子可用于EGCG/GCG和EGC/GC的区分。     

高分辨电感耦合等离子体质谱法测量放射性废液中239Pu与240Pu

²³⁹Pu和²⁴⁰Pu含量对分析放射性废液来源、选择后续处理工艺十分关键。本研究应用高分辨电感耦合等离子体质谱法（HR-ICP-MS）直接测定放射性废液中的²³⁹Pu、²⁴⁰Pu含量。由于²³⁸U与¹H结合产生的铀氢复合离子会对²³⁹Pu、²⁴⁰Pu造成同质异位素干扰,本研究通过测定铀氢复合离子产率进行质谱干扰修正,将²³⁹Pu、²⁴⁰Pu系列浓度标准扣除铀氢复合离子干扰后,分别绘制²³⁹Pu、²⁴⁰Pu质量浓度-计数率标准曲线。测量放射性废液样品时,先利用铀氢复合离子产率修正²³⁹Pu和²⁴⁰Pu的同质异位素干扰,再将样品计数率值代入标准曲线方程,计算得到放射性废液样品中²³⁹Pu和²⁴⁰Pu的质量浓度,最后计算²³⁹Pu和²⁴⁰Pu的活度。将质谱法与液闪法测量结果进行比对,结果表明,两者所测结果偏差小于4%,方法相对扩展不确定度为4.6%（k=2）。该方法制样简单,适用于辐射水平高、铀基体含量大的放射性废液中²³⁹Pu和²⁴⁰Pu的快速测量。