酸碱两种方法消解-电感耦合等离子体发射光谱法(ICP-AES)分析空气滤膜样品中的19种元素

特氟龙空气滤膜试样用反王水浸泡预消解,电热板加热,反王水-高氯酸-氢氟酸四酸体系分解滤膜样品吸附的空气颗粒物。在无合适监控样品的情况下,采用国家一级标准物质GBW07401模拟滤膜吸附的空气颗粒物与空白滤膜一起消化分解、上机测定,优化ICP-AES光谱仪的最佳测试条件,分析样品中的Ba、Cr、Cu、Li、Mn、Ni、P、Pb、Sr、Ti、V、Zn、Al、Ca、Fe、K、Mg、Na共18种元素,测定值与标准物质的认定值相符,各元素分析结果的相对标准偏差RSD在1.42%～9.21%之间,方法回收率在89%～112%之间,元素检出限在0.002 0～0.35 μg/g 之间。滤膜中的Si元素测定采用微波马弗炉碱熔法,水提取酸化定容,同步采用国家一级标准物质GBW03105a模拟空气颗粒物样品加入空白滤膜,灰化碱熔,进行ICP AES测定。相对标准偏差RSD为7.68%,检出限为0.12 μg/g。采用酸溶法和碱熔法2种方法分解样品,实现了空气滤膜样品中19个多元素的快速测定。     

微波密闭消解-等离子体质谱法测定岩石样品中的稀土元素

建立了有微波密封ＨＦ＋ＨＮＯ３消解样品,等离子体质谱测定岩石样品中１５个稀土元素的分方法。用该方法对国内外岩石标准品进行测定,结果表明稀土元素的测定值与标准值之间的相对偏差小于５％,检出限为（０．１－０．９）＊１０＾－９,多次测定结果的相对标准偏差在１．３％－５．２％。各类实际岩石样品中稀土元素的分析结果均与地质规律相符,进一步证明了方法的可靠性。     

锍镍试金富集-等离子体质谱法测定西太平洋富钴结壳中的铂族元素

根据西太平洋麦哲伦海山富钴板状结壳样品的成分特征，对常规的锍镍试金配方作了改进；酌情减少捕集剂羰基镍的加入量，可显著降低铂族元素的空白值。富集后的样品，采用电感耦合等离子体质谱测定铂族元素（PGE）。其中，Ru、Rh、Pd、Ir和Pt用常规外标法测定，^175Lu作内标；Os用同位素稀释法测定。用国家一级标准物质GBW07290和GBW07291作监控分析质量的参考样，结果满足要求。     

铼-锇同位素的等离子体质谱法测定及其在辉钼矿测年中的应用

研究了用ICPMS法测定地质样品Re-Os同位素的条件。通过选用Meinhard同心雾化器进样对Os(Ⅷ)水溶液进行测定,可使Os的测定灵敏度提高50倍。讨论了质量歧视效应校正中的有关问题。采用氧化剂清洗,克服了Os在进样系统中的严重记忆效应。用同位素稀释法测定了辉钼矿中Re和~(187)Os的含量,计算了成矿年龄。     

用粒子模拟方法研究离子声波

<正>向传播朗缪尔波被离子声波散射是太阳射电Ⅲ型暴基波和谐波激发的重要过程.使用粒子模拟方法对电子束流激发朗缪尔波的过程进行了模拟,同时对产生的反向朗缪尔波、朗缪尔波2次谐波和朗缪尔波通过非线性过程产生的离子声波的性质进行了分析研究.为了更好地研究离子声波,模拟时单独计算了由离子扰动引起的电场.模拟计算了不同初始参数下产生的离子声波强度,发现离子的温度和质量对离子声波的产生有重要作用,验证了反向朗缪尔波与离子声波的相关性.同时在模拟中验证了朗缪尔波的衰变过程,确认了离子声波对反向朗缪尔波的放大作用.     

电感耦合等离子体质谱法测定地质样品中的碲

本文采用电感耦合等离子体质谱法,对地质样品中的碲的测定进行了研究,建立了一种快速、准确、简便的测定土壤样品中碲的方法。该方法克服了常规方法的局限性。此方法对6个国家标准物质进行了方法验证,12次测定精密度、准确度均符合标准要求。     

Nano‐Powdered Calcium Carbonate Reference Materials: Significant Progress for Microanalysis?

Homogeneity, mass fractions of about forty trace elements and Sr isotope composition of Ca carbonate reference materials (RMs) between original and nano‐powdered pellets are compared. Our results using nanosecond and femtosecond LA‐(MC)‐ICP‐MS show that the nano‐pellets of the RMs MACS‐3NP, JCp‐1NP and JCt‐1NP are about a factor of 2–3 more homogeneous than the original samples MACS‐3, JCp‐1 and JCt‐1, and are therefore much more suitable for microanalytical purposes. With the exception of Si, the mass fractions of the synthetic RM MACS‐3 agree with its fine‐grained analogue MACS‐3NP. Very small, but significant, differences between original and nano‐pellets are observed in the RMs JCp‐1 and JCt‐1 for some trace elements with very low contents, indicating the need for re‐certification. Strontium mass fractions in the analysed RMs are high (1500–7000 mg kg^?1), and their isotope compositions determined by LA‐MC‐ICP‐MS in the original and the nano‐pellets agree within uncertainty limits.     

基于LC-MS/MS 技术对蓝藻Gloeobacter violaceus PCC 7421细胞膜的蛋白质组学研究

Gloeobacter violaceus PCC 7421是一种在进化上很古老的无类囊体蓝藻,由于光合作用电子传递链与呼吸系统在其细胞质膜上共存,这两个系统可能会共享一些元件,为研究其光合作用系统结构的独特之处,应用高效液相色谱-串联质谱联用(LC-MS/MS)技术对其细胞膜蛋白进行蛋白质组学分析.经鉴定发现, G. violaceus的细胞质膜上具有PSⅠ、PSⅡ和细胞色素b6等光合作用关键蛋白,同时具有呼吸作用过程中的关键酶1,5-二磷酸羧化酶/加氧酶、F0F1- ATP酶α和β亚基、细胞分裂蛋白、硝酸盐/亚硝酸盐转运蛋白、青霉素结合蛋白以及多种药物受体ABC转运蛋白.由此可知, G. violaceus的细胞质膜不仅能够同时进行光合作用和呼吸作用,且营养盐运输等转运功能也同时存在.G. violaceus的全基因数据分析显示其基因序列具有独特性,其蛋白注释相对比较少,因此其蛋白功能的研究需要更多数据的支持.     

Chemical Speciation of Vanadium in Coal Bottom Ash

Chemical speciation of vanadium is important to understand the true nature of this element in the environment as well as its biochemical pathways. Sample pretreatment, preparation, and chemical speciation methods were applied for vanadium in coal bottom ash here. Two‐stage microwave acid digestion was used to preparation of samples. Determination of vanadium was performed using inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Speciation of vanadium was carried out using a seven‐step sequential extraction procedure of the coal bottom ash each releasing species of vanadium: Water soluble, exchangeable, carbonate, reducible, oxidizable, sulfide, and residual fractions. Total vanadium concentration in the coal bottom ash is 701 mg kg^?1 d.w. The most abundant form of vanadium in coal bottom ash is residual fraction of vanadium (196 mg kg^?1 d.w.). Relative abundances of the remaining vanadium fractions in coal bottom ash are as follows: Reducible (176 mg kg^?1 d.w.) > sulfide (176 mg kg^?1 d.w.) > carbonate (85 mg kg^?1 d.w.) > oxidizable (50 mg kg^?1 d.w.) > water soluble (10.6 mg kg^?1 d.w.) > exchangeable (9.0 mg kg^?1 d.w.).     

Dynamics of cosmic current layers with localized lower-hybrid-drift turbulence

A two-dimensional magnetohydrodynamic model of the dynamics of tail-like current layers caused by anomalous electrical resistivity in a plasma with lower-hybrid-drift (LHD) turbulence is considered. Additionally to the LHD-resistivity, a resistivity pulse in the magnetic neutral sheet is given initiating a magnetic reconnection process. Then the temporal and spatial evolution of the magnetic and electric fields, the plasma convection and the anomalous resistivity are obtained numerically. Taking into account more exact expressions for the LHD-resistivity in the current layer as done in former works, the LHD-turbulence is found to be excited farther from the neutral sheet, and thus, with the time, secondary current sheets are obtained in the plasma-magnetic field system. It is shown that the inductive electric field moving from the magnetic neutral sheet to the current layer periphery during the reconnection process may be considered as indicator of the plasma disturbances.