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 共查询到16条相似文献,搜索用时 781 毫秒
1.
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.  相似文献   

2.
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。  相似文献   

3.
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。  相似文献   

4.
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.  相似文献   

5.
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)。  相似文献   

6.
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。  相似文献   

7.
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.  相似文献   

8.
9.
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.  相似文献   

10.
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。  相似文献   

11.
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.  相似文献   

12.
逯海  周涛  王军  赵墨田  李金英 《质谱学报》2008,29(Z1):23-24
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.  相似文献   

13.
为了实现快速分离钚与其他基体,准确测定钚同位素比值,建立了离子色谱(IC)与多接收电感耦合等离子体质谱(MC-ICP-MS)联用测定环境水样品中钚同位素比值的方法。实验选取7.5 mol/L硝酸作为色谱柱的上柱液,以0.35 mol/L HNO3和0.01 mol/L HF的混合溶液为淋洗液,用Pu计数最高点法(peak apex ratio)作为最终同位素比值的测定方法。实验对模拟环境水样进行测定,测量相对标准偏差为0.50%,与Pu标准同位素比值的相对偏差为5.7%。采用该方法对实际环境水样品进行测定,测量相对标准偏差为0.97%,与传统的TBP-7402色谱柱离线分离法测量的钚同位素比值进行对比,相对偏差为1.3%。结果表明,该方法的样品预处理简单、分离速度快、结果可靠,具有广阔的应用前景。  相似文献   

14.
The plutonium isotopic abundance ratio was analyzed by thermal ionization mass spectrometry (TIMS) with the ion counting technique. The ion counting system was developed and applied by our lab teem on the MAT261. It is verified with the certificated isotopic reference material. Using 3×10-9 g of plutonium, the combined standard uncertainty of ratio of 240Pu to 239Pu plutonium isotopes in 3 ng is 0.070%.  相似文献   

15.
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(fRe和 fIr)是不相等的,如果认为 fRe=fIr,将会导致187Re/185Re同位素比值偏低,但是 fRe/fIr比值固定不变,这样可以通过已知的 fIr 计算出 fRe,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 fRe=fIr 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。  相似文献   

16.
为满足核保障和核取证中含铀颗粒物分析的需求,建立了激光剥蚀-多接收电感耦合等离子体质谱(LA-MC-ICP-MS)测定铀颗粒物中~(235)U/~(238)U值的方法,并研究了铀颗粒物样品的装载、质量分馏的影响因素和校正方法,以及粒径10μm以下铀颗粒物的定位和分析等关键技术问题。建立了基于GBW04234的外标标准化法、基于膜去溶和LA-MC-ICP-MS联用的标准样品交叉法(SSB法)两种质量分馏校正技术,该方法对CRM124-1中~(235)U/~(238)U测量结果的相对扩展不确定度小于0.14%(k=2),测量结果与参考值在不确定度范围内一致。用显微操纵技术将颗粒物转移至覆盖定位铜网的导电胶表面,解决了微米级铀颗粒物的装载和定位问题,通过优化参数,实现了粒径5μm铀颗粒物中~(235) U/~(238)U比值的准确测量,测量结果的相对扩展不确定度小于0.64%(k=2)。  相似文献   

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