ICP-MS法分析尿中总铀和235U/238U比值及其不确定度评价

目的 建立电感耦合等离子体质谱（ICP-MS）快速测量尿中总铀含量和²³⁵U/²³⁸U比值的方法,并进行不确定度评价。方法 尿样经浓HNO₃和H₂O₂处理后,一部分定容直接进入ICP-MS测定总铀含量;一部分经磷酸三丁酯（TBP）萃淋树脂分离富集铀,采用ICP-MS测定其中²³⁵U/²³⁸U比值。以人尿样为例,通过样品前处理、测量、标准曲线计算,建立数学模型分析总铀及²³⁵U/²³⁸U比值的不确定度来源,进行不确定度合成。结果 该方法分析尿中总铀加标回收率为98.4%~102.4%,方法检出限为0.002 μg/L。经过不确定度评价,尿样中总铀含量的相对扩展不确定度为 0.26（k=2）;²³⁵U/²³⁸U比值的相对扩展不确定度为0.001 1（k=2）。结论 该方法加标回收率高,检出限低,精密度较好,能够实现尿中总铀的定量和²³⁵U/²³⁸U比值的快速分析,适用于放射职业照射或核应急的公众照射中尿铀及²³⁵U/²³⁸U比值的分析;尿中总铀及²³⁵U/²³⁸U比值不确定度评定结果准确可靠。     

多级大气颗粒物中超痕量铀的HR-ICP-MS分析方法研究

目的 建立有效可靠地分析多级大气颗粒物中超痕量铀的方法,为环境大气中放射性铀含量的监测与评价提供快速可靠的分析方法。方法 采用撞击式六级空气采样器进行采样,对比纤维素、玻璃纤维和石英3种采样滤膜和4种酸消解体系,选择最优滤膜和消解酸系,利用微波消解-高分辨电感耦合等离子体质谱仪测定颗粒物中超痕量铀的含量。结果 纤维素带槽滤膜的铀本底含量最低,优选HNO₃-HCl （王水）-H₂O₂体系消解。利用建立方法分析标准膜（SRM2783）的实验结果相对误差为7%,铀的检出限为2×10^-4 ng/m³。应用此方法分析实际PM_2.5颗粒物中铀的含量约为0.023~0.065 ng/m³。结论 建立的方法能够有效监测多级大气颗粒物中超痕量铀的浓度水平,分析方法准确可靠。     

精神分裂症患者血清41种微量元素定量检测及分析

目的探讨血清中多种微量元素含量改变与精神分裂症的关系。方法应用高灵敏度的电感耦合等离子体质谱仪与原子发射光谱仪定量检测了119例精神分裂症患者血清中41种微量元素含量,并与126例正常人做对照,结合患者不同性别、不同年龄段及不同病程进行了分组比较。结果患者组硼、铝、锶、锂、镍、锑、铬、锰、钾、钠、磷11种元素血清含量显著升高;钛、锗、砷、钴、镉、锡、铋、钍、铀、铊、镧、铈、镨、钕、钆、铜、硫、锌18种元素血清中含量显著降低。精神分裂症患者组与性别差异相关的元素有磷、砷、铷、钛、锑;与不同年龄段相关的元素有硼、铜,不同病程比较血清元素含量无明显相关性。结论多种微量元素广泛参与了精神分裂症的发病及病理过程,多种元素的丰缺或多元素的综合作用可能是造成患者中枢神经系统功能紊乱的元素基础。     

Accurate determination of 129I concentrations and 129I/137Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry

Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low ¹²⁹I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO₃/HClO₄, (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured ¹²⁹I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of ¹²⁹I/¹³⁷Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples.     

内蒙古锡林郭勒盟饮用水中铀含量和铀同位素丰度分析

目的 采集内蒙古锡林郭勒盟饮用水中铀含量和铀同位素丰度数据。方法 采集内蒙古锡林郭勒盟有代表性的饮用水,利用电感耦合等离子体质谱(ICP-MS)法分析样品中U含量以及²³⁴U/²³⁸U与²³⁵U/²³⁸U同位素丰度。结果 样品中U浓度范围2.73~18.9 μg/L,平均值为8.20 μg/L;²³⁴U/²³⁸U的范围7.513×10^-5~3.003×10^-4,测量的相对不确定度(RSD)小于0.5%;²³⁵U/²³⁸U的范围7.196×10^-3~7.391×10^-3,测量的相对不确定度(RSD)小于0.2%。结论 东乌旗自来水样品中U含量高于世界卫生组织饮用水中U含量的限值(15 μg/L);饮用水中的铀主要来源于天然环境;水样品中²³⁴U被不同程度的富集。     

衍生化液质联用法测定大鼠血浆中丹皮酚的浓度

目的 建立灵敏、可靠的衍生化液质联用法测定大鼠血浆中丹皮酚的浓度.方法 血浆样品前处理包括蛋白沉淀和用对甲苯磺酰肼为衍生化试剂的衍生化反应,测定采用液质联用法.通过电喷雾电离源以选择离子监测方式进行正离子检测,用于定量分析的离子反应分别为m/z 335(丹皮酚衍生物)和m/z 479(内标孕二烯酮衍生物).色谱分离采用...     

Correlation and Agreement of Yttrium-90 Positron Emission Tomography/Computed Tomography with Ex Vivo Radioembolization Microsphere Deposition in the Rabbit VX2 Liver Tumor Model

PurposeTo demonstrate a stronger correlation and agreement of yttrium-90 (⁹⁰Y) positron emission tomography (PET)/computed tomography (CT) measurements with explant liver tumor dosing compared with the standard model (SM) for radioembolization.Materials and MethodsHepatic VX2 tumors were implanted into New Zealand white rabbits, with growth confirmed by 7 T magnetic resonance imaging. Seventeen VX2 rabbits provided 33 analyzed tumors. Treatment volumes were calculated from manually drawn volumes of interest (VOI) with three-dimensional surface renderings. Radioembolization was performed with glass ⁹⁰Y microspheres. PET/CT imaging was completed with scatter and attenuation correction. Three-dimensional ellipsoid VOI were drawn to encompass tumors on fused images. Tumors and livers were then explanted for inductively coupled plasma (ICP)-optical emission spectroscopy (OES) analysis of microsphere content. ⁹⁰Y PET/CT and SM measurements were compared with reference standard ICP-OES measurements of tumor dosing with Pearson correlation and Bland-Altman analyses for agreement testing with and without adjustment for tumor necrosis.ResultsThe median infused activity was 33.3 MBq (range, 5.9–152.9). Tumor dose was significantly correlated with ⁹⁰Y PET/CT measurements (r = 0.903, P < .001) and SM estimates (r = 0.607, P < .001). Bland-Altman analyses showed that the SM tended to underestimate the tumor dosing by a mean of ?8.5 Gy (CI, ?26.3–9.3), and the degree of underestimation increased to a mean of ?18.3 Gy (CI, ?38.5–1.9) after the adjustment for tumor necrosis.Conclusions⁹⁰Y PET/CT estimates were strongly correlated and had better agreement with reference measurements of tumor dosing than SM estimates.