非完全消化-火焰原子吸收光谱法测定润滑油中钙锌

在低温加热的条件下,油样用浓硝酸消化,所得试液中加入适量Triton X-100及Tween 80使乳化从而得到均匀的透明或半透明的呈橙黄色或黄绿色的试样溶液,供火焰原子吸收光谱法(FAAS)测定钙及锌.对非完全消化所用的酸和乳化剂的选择和FAAS测定中的化学干扰、背景干扰以及空白溶液及试样溶液粘度的一致性等分析务件进行了试验和优化.钙及锌两元素的线性范围依次为0～12 mg·L-1和0～1.6 mg·L-1,检出限(3σ/s)依次为0.14 mg·L-1及0.018 mg·L-1.此方法应用于润滑油实样分析,所得两元素分析结果的RSD(n=6)值均小于5%,回收率均在100.0%～102.1%之间.     

火焰原子吸收光谱法测定纯棉纺织品中锌和锰的可提取态与总量

采用酸性汗液提取纯棉纺织品中锌和锰,火焰原子吸收光谱法(FAAS)测定可提取态含量;同时建立了微波辅助消解溶样,FAAS测定纯棉纺织品中锌和锰总量的方法。锌和锰的检出限分别为2.0和3.0μg·L-1,可提取态和总量测定结果的相对标准偏差在1.8%～6.6%之间,加标回收率在91.2%～104.8%范围。对5种北京市市售纯棉纺织品测定,锌的可提取态含量在0.31～3.26μg·g-1之间,总量为3.43～37.93μg·g-1;锰的可提取态含量在0.19～1.39μg·g-1之间,总量为0.56～3.17μg·g-1。     

火焰原子吸收光谱法及比浊法测定聚氯乙烯中氯

以无水碳酸钠为灰化固定剂,于瓷坩埚中加热将试样灰化,于高温炉中在700℃燃烧2 h,用水溶出残渣,分取部分试液用火焰原子吸收光谱法(FAAS)或浊度法测定其中氯离子.加入过量银以沉淀样品溶液中的氯离子,用FAAS法测定银以间接测定氯,或通过测定氯化银悬浮体的表观吸光度而测定氯,建立了FAAS法及比浊法测定聚氯乙烯中氯含量的方法.线性范围:FAAS法为0～140μmol·L-1,比浊法为0.4～4.8 mg·L-1.测定结果的相对标准偏差≤1.9%,加标回收率95.0%～102.5%.两种方法测定结果的相对误差小于士1.1%.     

电感耦合等离子体质谱法同时测定枇杷叶中多种无机元素

枇杷叶试样于聚四氟烯消解罐中加入硝酸及过氧化氢置于微波炉中加热消解,对所得试样溶液中的14种无机元素用电感耦合等离子体质谱法同时测定.在测定钙、锰、镁、磷及铁的试验中,测得其线性范围在0～200μg·L-1之间,用标准加入法对所测定的14种无机元素作了回收试验,所得回收率在90%～110%之间.按规定要求测定14种无机元素的检出限,测得结果在0.002～0.4μg·L-1之间.     

花椒中五种微量元素含量的测定

采用原子吸收光谱法,测定了河南太行山区花椒及椒皮、椒籽中锰、铁、铜、锌、铅的含量。结果显示,各元素在实验范围内,线性关系良好,回收率在92%~103%之间。花椒及椒皮、椒籽中均含有微量元素,花椒中锰、铁、铜、锌、铅的含量分别为78.851、90.868、11.571、18.818、0.086μg.g-1,其中锰、铁含量丰富,有害元素铅的含量极低。椒籽中铁、铜、锌的分布量大于椒皮;椒皮中锰的分布量大于椒籽。为探讨花椒的高药用价值提供了有力的证据,椒籽中铜、锌、铁含量高于椒皮,应大力开发利用。     

土壤中铅的含量及其化学形态分析

对广州市黄埔港区所取土壤中铅的化学形态分析进行了研究。采用含不同组分提取剂的连续提取程序对1 g土壤进行提取,使之分成8种形态的铅,并用火焰原子吸收光谱法(FAAS)对每种提取所得的形态中的铅进行了测定。另在一份试样中直接测定其总铅量,对提取剂的组成及其溶液的浓度及提取操作条件进行了研究和优化,对FAAS测定方法的仪器工作条件作了说明。试验结果表明,所取试样中大部分铅以稳定的结合形态存在,以可交换态和碳酸盐结合态存在的铅仅达6%,总铅量随土壤深度的增加而减少。FAAS测定方法的灵敏度和检出限依次为0.007 mg.L-1及0.01 mg.L-1,分析和测定了4个试样中8种形态的铅量,其加和量为147.9 mg.kg-1,与直接测得的总铅量(159.9 mg.kg-1)之间的偏差小于10%。     

TBP柱上分离—ICP—AES法测定二氧化铀中微量杂质元素

用ICP-AES法对二氧化铀中23个微量杂质元素进行了测定.取样量100mg时铝、钡、钙、钴、铬、铜、饵、铁、铪、铟、镁、锰、钼、铌、钛、铅、锡、钽、镍、钒、钇、锌和锆的测定范围是20～800μg·g~(-1),回收率为94%～106%,RSD(n=8)为0.2%～1.6%.     

茶叶中多元素的微波消解等离子体发射光谱法测定

采用密闭式微波消解系统处理茶叶样品,以电感耦合等离子体发射光谱法测定茶叶样品中铜、铁、锌、锰、钡和铝6种元素.分别从消解液的选择、用酸量及样品消解量等方面进行消解条件的优化,对测定钡、铝元素存在的干扰进行了讨论.各元素的检出限范围为0.15～0.65μg·g-1,回收率为98.6%～106%,精密度为0.8%～5.3%...     

共沉淀-微量进样火焰原子吸收光谱法测定海水中铁和锰

海水中微量铁和锰用氢氧化镁共沉淀法预富集,所得沉淀溶于1.0 mL HNO3(1 3)中,分取250 μL进样作铁与锰的火焰原子吸收光谱法(FAAS)测定.经此处理,克服了海水的基体干扰.用于测定北仑港近岸海域海水中铁和锰,方法检出限分别为6.4,3.0 μg·L-1.     

电感耦合等离子体原子吸收光谱法测定木菠萝树叶与树干中12种元素

采用用电感耦合等离子体原子发射光谱法测定了木菠萝树叶与树干中铁、锰、铜、锌、钙、镁、钠、钾、铝、铅、镉和镍等12种元素含量。试样用灰化法处理,其残渣用稀硝酸和过氧化氢溶解。选择硝酸(2+98)溶液作为介质,选择波长为238.204,257.610,327.393,206.200,317.933,285.213,589.592,404.721,396.153,220.353,228.802,221.648 nm 12条谱线依次作为铁、锰、铜、锌、钙、镁、钠、钾、铝、铅、镉和镍的分析线,测得12种元素的检出限(3s)均低于0.100 mg.L-1。方法用于木菠萝树叶和树干试样分析,所得测定值的相对标准偏差(n=6)为0.38%~5.52%。     

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).     

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。     

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.     

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.     

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.     

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。     

含茂基苯并三氮唑基镧系有机配合物的合成及表征

三茂基镧系化合物和苯并三氮唑在四氢呋喃中反应,合成了7个未见文献报道的含茂基苯并三氮唑基镧系有机配合物,经元素分析、IR和MS测定,从有关数据推测了这类配合物的可能结构。