阳极溶出伏安法连续测定土壤中的铅、镉和铜

文章研究了应用阳极溶出伏安法 ,在 0 .1 mol/ L NH3 - NH4Cl底液中 ,以银基汞膜电极为工作电极 ,连续测定了土壤中的铅、镉和铜三种元素的方法。在选定的实验条件下 ,铅、镉和铜的浓度分别在 1 0～ 360 μg/ L、5～ 2 4 0 μg/ L、2 0～ 42 0 μg/ L的范围内与峰高成线性关系。样品测定结果表明 ,方法简便可靠 ,令人满意     

鱼油中多氯联苯的气相色谱-质谱(GC/MS)分析

采用凝胶渗透色谱法 (GPC)和 Florisil土填充的 SPE小柱对鱼油样品进行净化处理 ,应用 GC/MS的分段选择性离子监测 (SIM)定性定量分析。结果表明 :SIM法可以定性分析鱼油实际样品中 3 1种多氯联苯 ,检测限为 1 0～ 1 0 0 fg,定量分析了其中的七种用来监测海洋受污染程度的多氯联苯     

电感耦合等离子体质谱测定生物样品中超痕量稀土元素(英文)

本文描述了用电感耦合等离子体质谱仪分析生物样品中超痕量稀土元素的方法 ,采用优良的测试方法和合适的样品处理程序 ,对毛发、血清、血液和组织样品的稀土成份分析能够获得高的准确度和精密度 ,检测限达到 7～ 2 6 pg/m L。 GBW 0 91 0 1品稀土元素的回收率为 95～ 1 0 5% ,相对标准偏差为 2 .6～ 4.2 %。     

3.53μm激光外差太阳光谱测量系统

激光外差技术具有高光谱分辨率特性,常用于地球大气探测研究,尤其是测量整层大气透过率及气体浓度反演。本论文设计了以窄线宽3.53μm分布反馈式带间级联激光器作为本振光源的激光外差系统,实现了整层大气中水汽和甲烷气体吸收光谱的测量,系统光谱分辨率达到0.002cm-1,信噪比为24.9dB,达到多普勒线型吸收谱线的测量要求。利用自行搭建的测量系统测量了3.53μm波段整层大气透过率,与辐射传输软件仿真分析结果进行对比,其绝对差值小于0.1,实测透过率与仿真透过率具有相同的变化趋势。该系统结合最小二乘法实现了实际大气中水汽和甲烷的同步反演,合肥地区春季水汽和甲烷的柱浓度均值分别为1.20g/cm2和1.31mg/cm2。通过对3.53μm激光外差太阳光谱测量系统的研究,掌握了调提高光谱分辨率和信噪比的方法,为获取大气分子更加准确的吸收谱线和气体浓度反演奠定了基础。     

变截面 FeGa 膜 / AT 切石英晶片复合谐振磁场传感器

提出用变截面 FeGa 磁致伸缩膜与 AT 切石英晶片双面复合的磁场传感结构,变截面形状降低了磁膜汇聚区域的退磁 因子,进而将磁致伸缩应变汇聚到晶片的电极区域。 同时双面复合结构避免了晶片中沿厚度方向的应变方向发生改变,两者结 合提高了谐振传感器的磁场灵敏度。 推导的灵敏度公式表明,灵敏度与复合结构确定的应变传递系数、磁膜材料的压磁系数以 及磁膜厚度均成正比,与晶片厚度的平方成反比。 在厚度为 200 μm 的 AT 切石英晶片表面双面沉积 1 μm 厚的变截面 FeGa 膜 制备传感器样品,测试结果表明:传感器 Q 值为 5 489,线性区间的灵敏度达到 -0. 82 Hz / Oe,据此,当晶片厚度降低至 7. 5 μm 时,传感器灵敏度将达到 -583 Hz / Oe,并且可通过采用更高压磁系数的材料进一步提高。     

膜去溶和ICP-MS联用冷焰模式直接测定CMOSⅡ40％_HF中金属离子的含量

文章建立了直接测定半导体二级40％含量氢氟酸(CMOSⅡ40％_ HF)多元素含量的方法.以膜去溶作为进样系统,电感耦合等离子体质谱仪(ICP-MS)作为分析仪器,分别采用热焰和冷焰模式分析,首先测定CMOSII 40％_ HF,然后测定以Be、Co、In和Bi作为加标的CMOSII 40％-HF,加标样品测定加标回收率,同时测定Na、Mg、K、Ca和Fe的检出限.实验结果证明该方法具有进样速度快、精密度高等优点,冷焰模式降低了Na、Mg、K、Ca和Fe的检出限,同时降低了CMOSⅡ40％_ HF的检出下限,提高了准确度.膜去溶与ICP-MS联用是快速分析高纯度HF中金属离子的有效方法,膜去溶的使用解决了使用玻璃雾化器和石英炬管时HF无法直接进样的问题,有效地减小了基体干扰,同时冷焰模式提高了碱金属元素的测量精度.     

大气浓度下N2O中氮稳定同位素比值测定的GasBench-IRMS系统改造

为实现在线自动测定大气环境N₂O中氮稳定同位素比值,本工作对多用途在线气体制备和导入系统（GasBench）进行了改造。增加了化学阱和2个冷阱,与八通阀构成预浓缩装置,以期达到纯化和浓缩大气样品中N₂O的目的,同时更换大体积进样瓶及其配套样品盘,用于增加样品进样量。优化了质谱测定条件、样品收集和浓缩时间等关键参数,并进行了系统的线性、稳定性测试以及方法准确性验证。结果表明,在本方法条件下,当离子流强度在280～3000 mV时,系统线性关系良好,δ¹⁵N_Air值随离子流强度的增加而变化不大;不同压力条件下,δ¹⁵N_Air值的S.D<0.04‰,达到仪器稳定性指标的要求。利用该方法测量配制的400 mg/L N₂O标准样品气,δ¹⁵N_Air平均值为7.253‰,接近标准气的氮稳定同位素标准值,说明该方法准确性良好,可用于大气浓度下N₂O中氮同位素比值测定。     

AZ91D镁合金微弧氧化低能耗的电解质配方研究

利用自制微弧氧化装置在铝酸盐体系中对AZ91D镁合金进行微弧氧化处理.采用多重正交试验,从考察膜层厚度、单位能耗和耐蚀性出发,确定了AZ91D镁合金在铝酸盐体系中的最佳工艺参数.结果表明:在最佳电解质配方下,处理过程工作电压约在120 V,电流密度可以低到0.5 A/dm2,生长1 μm陶瓷涂层的单位面积能耗仅为456 W/(m2·μm).微弧氧化膜呈多孔结构、孔径较小,裂纹较少,分布均匀,膜层较为致密;微弧氧化膜由MgO和MgAl2O4组成;处理后AZ91D镁合金样品的腐蚀电流密度为0.014 μA/cm2,比未处理合金降低了接近3个数量级.     

热表面电离源同位素丰度测量的理论模型

根据对热表面电离源同位素丰度测量过程中样品蒸发的微观研究 ,提出如下三条假设 :(1 )未被外层原子覆盖的原子才能蒸发 ;(2 )被外层原子覆盖的原子只能扩散不能蒸发 ;(3 )同位素原子的扩散几率与蒸发几率成正比。根据这三条假设建立了样品原子数的微分方程及边界条件 ,推导出了不同扩散系数的样品原子数的理论公式 ,从理论上讨论了熔融态、固态样品以及蒸发分解同时发生的样品同位素丰度比与样品消耗量间的关系。研究表明 :扩散系数 >1 0 -15m2 / s的样品同位素丰度比与样品消耗量的关系与 H.Kanno得出的结论相同 ,扩散系数 <5× 1 0 -2 1m2 / s的样品同位素丰度比与样品消耗量无关 ,等于实际值 ;蒸发分解同时发生的样品同位素丰度比与分解率蒸发率之比有关     

氢醌-双(β-羟乙基)醚工业品中相关杂质的气相色谱-飞行时间质谱定性研究

建立了气相色谱 -飞行时间质谱 ( GC-TOFMS)法测定聚氨酯扩链剂氢醌 -双 ( β-羟乙基 )醚 ( HQEE)工业品中相关杂质的方法。以 5 0 mg HQEE溶解于约 5 0 m L异丙醇中 ,选用 HP-5毛细管柱 ( 3 0 m× 0 .2 5 mm× 0 .2 5μm)进行分离并对其中所含相关杂质进行了定性研究 ,通过色谱保留值和质谱图的信息推断出HQEE样品中主要杂质。结果表明 :样品中三个主要杂质均可被准确定性为 HQEE的同系物 ,相对分子质量分别为 1 5 4、2 42和 2 86。根据合成工艺路线推测出杂质的结构。考察了样品合成过程中环氧乙烷的用量。该方法可及时解决 HQEE产品在合成工艺中出现的问题 ,有效控制并提高产品的质量     

多接收电感耦合等离子体质谱法精确测量

经过核燃料后处理得到的铀产品中含有极微量钚杂质, 对其同位素组成进行分析有利于对应铀材料的溯源。本工作在铀钚化学分离的基础上,对影响MC-ICP-MS法精确测量痕量钚同位素丰度比值的仪器条件进行了优化,研究了仪器分辨率、离子提取模式的选择、“背景和干扰”等参数的影响,探索研究了MC-ICP-MS上质量偏倚的校正方法。对选择的两个后处理铀产品中痕量钚同位素比进行了测量,当铀钚比例达10¹⁰时,测得的²³⁹Pu/²⁴⁰Pu相对不确定度优于5％。并且建立了在MC-ICP-MS上测量ng•L^-1量级钚同位素丰度比值的方法。     

多接收电感耦合等离子体质谱测定皮克量级钚240Pu/239Pu的方法研究

In order to analyze plutonium isotope ratios precisely at picogram levels by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), the various parameters of instrument were optimized. The interference caused by uranium, thorium, lead and other metal ions were studied. The mass bias and the inter-detector bias can be obtained by using the reference material of uranium. The results that the accuracy of 240Pu/239Pu is less than 0.5% at 50 pg·g－1 level when this method is utilized.     

电热蒸发-电感耦合等离子体质谱法测量铀、钚同位素丰度

A method on determination of isotope ratio of 235U/238U and 239Pu/240Pu by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICPMS) is developed. The operation parameters of ETV and ICPMS are optimized respectively. The absolute detected limit is 0.3 pg (3k), and the RSDs of 235U/238U and 239Pu/240Pu are better than 5%.     

多接收电感耦合等离子体质谱法测量痕量钚同位素

The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct the metrical data, and the analytical precision is about 0.5%.     

Anthropogenic Plutonium in Soils of the Ural Region

The Pu content and distribution in soils of certain territories of the Ural region located in zones of nuclear accidents and regular operation of power reactor facilities are studied. The maximum content of ^239;240Pu isotopes (up to 5000 Bc/m²) was revealed in soils of the central axis of the East Ural radioactive contamination at a distance of 30 km from the accident point. Regular gas-aerosol releases from the PO “Mayak” plants appreciably contribute to contamination of the neighboring territories. It is shown that almost 10¹² Bc of ^239;240Pu was released in the environment as a result of two nuclear accidents in 1957 and 1967. The nonuniform terrestrial plutonium contamination (from 200 to 5000 Bc/m²) is noted within the expected central axis of the Totsk radioactive trail. The contribution of the Beloyarsk nuclear power plant to the soil contamination in the fall-out zone of the aerosol emission plume is estimated on the basis of an analysis of the ²³⁸Pu/^239;240Pu isotope ratio.     

电感耦合等离子体发射光谱法(ICP-AES)测定矿石中钼

本文报道了电感耦合等离子体发射光谱(ICP-AES)快速测定矿石中钼的方法 ,为了消除矿石的基体干扰,溶解国家一级标准样品制备成标准系列的标准溶液,制作校准曲线。钼的测定波长为202.030nm。本法检出限为0.094μg/mL,实际测定矿石中大于0.005%以上的钼。相对标准偏差(RSD)的范围:0.12%～1.4%。标样测定结果与国家标准样品值结果一致,矿石样品测定值与分光光度法测定结果一致。     

Mass spectrometry of atmospheric aerosols--recent developments and applications. Part II: On-line mass spectrometry techniques

Many of the significant advances in our understanding of atmospheric particles can be attributed to the application of mass spectrometry. Mass spectrometry provides high sensitivity with fast response time to probe chemically complex particles. This review focuses on recent developments and applications in the field of mass spectrometry of atmospheric aerosols. In Part II of this two-part review, we concentrate on real-time mass spectrometry techniques, which provide high time resolution for insight into brief events and diurnal changes while eliminating the potential artifacts acquired during long-term filter sampling. In particular, real-time mass spectrometry has been shown recently to provide the ability to probe the chemical composition of ambient individual particles <30 nm in diameter to further our understanding of how particles are formed through nucleation in the atmosphere. Further, transportable real-time mass spectrometry techniques are now used frequently on ground-, ship-, and aircraft-based studies around the globe to further our understanding of the spatial distribution of atmospheric aerosols. In addition, coupling aerosol mass spectrometry techniques with other measurements in series has allowed the in situ determination of chemically resolved particle effective density, refractive index, volatility, and cloud activation properties.     

激光共振电离质谱法选择性电离铀钚混合物中的痕量钚

利用实验室开发的激光共振电离质谱仪,初步建立了激光共振电离质谱测定钚同位素比值的方法。通过扫描测量钚原子的自电离态能级,获得了一种具有较大电离截面的三色三光子共振电离方案。对铀钚混合物模拟样品,钚元素相对于铀元素的选择性在5×10⁶以上,²⁴⁰Pu/²³⁹Pu比值测量结果的相对标准偏差为1.1%。结果表明,激光共振电离质谱技术能有效避免同量异位素干扰以及其他元素带来的强峰拖尾干扰。     

亚皮克量级钚的质谱分析技术

By using active carbon powder as ionization enhance matter, the detect sensitivity of 239Pu ,which was 0.5 pg (1±0.15, 95% confidence level), was about 20 times that of the tradition method. The sub-picogram plutonium sample was determined quantitatively by isotope dilution mass spectrometry (IDMS).     

钚气溶胶直接进样ICP-MS快速分析技术-6级高效过滤器后钚气溶胶的定量

A technique for fast analysis of plutonium in airborne aerosol was developed with directly sampling ICP-MS in this laboratory. And the Pu-242 aerosol particle addition calibration method was established. The nebulized Pu-242 solution aerosol was quantitatively mixed with the airborne aerosol and then introduced into ICP-MS. The results show that the detection limit for Pu-239 concentration is down to 1.4×10^－6 Bq·L^－3. The airborne aerosol sample after through a high efficiency particulate air (HEPA) filter with six stages (efficiency per stage 99.95%) was analyzed using this technique, the plutonium concentration determined is 3×10^－4 Bq·L^－3. However plutonium could not be detected when sampling using HEPA filter at same situation, airborne aerosol also could not be detected at same situation with Condensation Particle Counter (CPC). This result shows there were some tiny plutonium particulates which passed through the six stages HEPA filter with airflow and could not be collected by the HEPA filter