电感耦合等离子体质谱法测定环境评价性土壤中铬铜镉铅

针对环境评价性土壤,采用HNO_3-HClO_4-HF消解样品、HNO_3提取技术,以52Cr、65Cu、114Cd、208Pb作为测定同位素,采用间接经验公式校正质谱干扰,最终实现了电感耦合等离子体质谱法(ICP-MS)同时对Cr、Cu、Cd、Pb等4种重金属的测定。详细对比分析了HCl-HNO_3-HClO_4-HF、HCl-HNO_3-H_2SO_4-HF、HNO_3-HClO_4-HF消解法等3种试样处理方法对土壤成分分析标准物质的分析数据,结果表明:HNO_3-HClO_4-HF消解法测定值与认定值相符。Cr、Cu、Cd、Pb的校准曲线相关系数均达0.9999以上,方法测定限(μg·L~(-1))分别为:Cr1.54,Cu 0.83,Cd 0.024,Pb 0.29。将方法应用于土壤4种重金属元素的测定,结果与认定值基本一致,相对标准偏差(RSD,n=12)均小于8%,加标回收率在96.7%~102.3%。方法应用于实际环境评价性土壤样品分析,结果与X射线荧光光谱法(XRF)相吻合。     

海洋及河口沉积物中15种微量及常量元素的原子吸收分光光度法测定

海洋及河口沉积物是物质迁移的重要归宿,了解沉积物的微量及常量元素化学组成对海洋地球化学的研究具有重要意义。消解沉积物的方法很多,目前大多在铂坩埚或聚四氟乙烯烧杯中采用酸消化,如王水、HNO_3-HClO_4-HF、王水-HF等。近年来发展起一种全聚四氟乙烯厚壁消化罐,完全排除了金属材料,适用于微量金属的分析。     

土壤环境背景值试样的前处理研究

土壤是人类赖以生存的重要环境要素之一,环境保护工作者已将对土壤的研究列为重点研究对象.“七五期间”,全国进行了土壤环境背景值研究.这项研究工作,在合理布点,正确采样的基础上,土壤样品的前处理成为获取准确结果的关键步骤之一.关于这方面的研究已有不少报道,本工作对土壤样品的过氧化钠碱熔融、HNO_3-HClO_4-HF、HNO_3-HClO_4-HF封闭增压分解法进行了比较研究,分解好的土壤样品用苯羟乙酸催化极谱法测V,原子吸收法测定Cu、Pb、Zn、Cd、Cr、Co、Ni、Mn等.结果表明,后两法适于作为     

土壤和沉积物中全硼量与其他微量及常量元素的ICP-AES同时测定

用含有氢氟酸的混酸(H_3PO_4-HClO_4-HNO_3-HF或H_3PO_4-HNO_3-HF)分解样品,磷酸的存在可以避免硼挥发损失。利用ICP-AES法同时测定土壤和水系沉积物样品中全硼量及其他18个常量及微量元素,对标准参考物质的分析结果表明,方法有良好的准确度和精密度。硼的回收率在84.8—100％之间,相对标准偏差小于7.4％(微量元素)和小于3.9％(大量和小量元素)。方法适合于土壤和沉积物批量样品的多元素快速分析。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定硒片中的硒、铁、钙和锌

用HNO_3-HClO_4(4∶1)溶解硒片,电感耦合等离子体原子发射光谱(ICP-AES)法测定其中的硒、铁、钙和锌,实验表明硒片中硒、铁、钙和锌的含量较为丰富,与外包装承诺的含量一致。方法灵敏可靠,测量相对标准偏差3%,加标回收率在96.5%~101%,实验结果为探讨硒片对人体的保健作用提供了参考数据。     

硒的气相色谱法测定

本文报告用气相色谱法测定环境中多种样品如污水、海水、土壤、底质、作物、以及海洋生物等样品中的痕量硒。比较了数种处理样品的方法,确定以钼酸钠为催化剂的硫酸-高氯酸混合酸氧化有机物较为完全,适合于气相色谱法测定。消解后的浓酸溶液不需经其它处理,直接用水稀释即可在高至5N的酸度下,加入4-硝基邻苯二胺与硒作用生成可挥发的5-硝基-2,1,3-苯并硒二唑化合物,用甲苯萃取,气相色谱法测定。数十种元素不干扰。方     

电感耦合等离子体质谱法测定土壤中痕量铊的方法研究

采用电感耦合等离子质谱法(ICP-MS)测定土壤中的痕量铊,并对前处理方法进行研究,建立了一种使用HNO_3-H_2O_2-HF酸消解体系测量土壤中痕量铊的方法。该方法在0.00~5.00μg/L范围内线性良好,相关系数为0.999 8,方法检出限为0.1 ng/kg,对4份铊土壤标准样品测定的结果均在保证值范围内,RSD为1.8%~6.6%,2份土壤实际样品的加标回收率为95.4%~102.4%。     

氢化物发生-原子荧光光谱法测定海洋沉积物中砷、锑、铋、汞、硒

提出了用盐酸-硝酸-水(3+1+4)混合酸消解样品,氢化物发生-原子荧光光谱法测定海洋沉积物样品中砷、锑、铋、汞、硒的方法。考察了原子荧光光谱仪的最佳工作条件。在最佳条件下砷、锑、铋、硒的检出限(3s/k)分别为0.018,0.004,0.001,0.003μg.g-1,汞的检出限(3s/k)为0.604ng.g-1。应用于3种海洋沉积物标准物质的测定,测定值与标准值吻合。     

电感耦合等离子体质谱法测定接装纸中砷、钼、镉、铊和铅

建立了一种同时测定接装纸中砷、钼、镉、铊和铅5种元素的电感耦合等离子体质谱分析方法,实验采用微波消解前处理样品,HNO3-H2O2-HF混合体系作消解剂。方法的加标回收率94.79%~114.6%,检出限0.002~0.18μg/L,相对标准偏差1.1%~4.4%(n=5),线性相关系数0.9996~1.000。用所建立的方法测定了17个牌号接装纸中砷、钼、镉、铊和铅的含量,结果发现:砷、钼、镉、铊和铅在接装纸中的含量较低,其平均值均低于1.0μg/g,接装纸中钼和铊两种元素的变异较大,镉的变异最小,其变异系数分别为98.5%、151.1%,53.0%。     

一次消解土壤样品测定汞、砷和硒

建立了测定土壤中3种挥发性元素(汞、砷、硒)的一次消解方法,确定以程序控温石墨自动消解仪+王水-氢氟酸-硼酸络合敞开体系为最佳消解体系,采用氢化物发生-原子荧光光谱法(HG-AFS)分别测定同一消解液中汞、砷、硒的含量.采用国家标物中心有证标准物质土壤环境样品GSS-1~GSS-8进行了方法验证,结果均符合标准偏差的允许范围.此消解方法相比于现行标准方法,避免了针对各元素的分次处理,简化了消解步骤,节省了前处理时间,减少了试剂消耗,提高了实验效率,适用性广、灵敏度高、检出限低,尤其适合批量样品的微量/痕量元素分析,可作为一种大规模土壤样品中重金属污染监测和治理的快捷方法.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.