共查询到20条相似文献,搜索用时 234 毫秒
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该文对质谱鉴定技术及其与色谱联用的分析方法(包括直接进样质谱分析、气相色谱质谱联用技术、超临界流体与质谱联用技术和液相色谱质谱联用技术)在甘油三酯分析方面的应用进行了综述,评述了各类分析方法的优缺点,对常用的脂质分析数据库进行了介绍,并对甘油三酯分析方法的发展及应用作了展望. 相似文献
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综述了水环境中元素形态分析技术研究进展。水环境中元素形态分析技术主要包括电感耦合等离子体质谱法、原子荧光法、气相色谱法、比色法、毛细管电泳法、原子吸收光谱法等技术及其联用技术。电感耦合等离子体质谱与液相色谱联用技术选择性好、分析速度快、分离效果好;原子荧光与液相色谱联用技术灵敏度高、检出限低、操作简单;气相色谱与电感耦合等离子体质谱联用技术可以实现非常低的检测限和良好的回收率。探索新技术的相互融合,提高元素形态分析技术的灵敏度,获得更低的检测下限,降低分析成本,是未来研究的重点。 相似文献
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分析化学教学体系重构之思考 总被引:4,自引:0,他引:4
结合分析化学学科的发展和分析化学学科的内涵定义,对现行分析化学课程的教学内容进行了分析,指出了现行分析化学课程教学的缺失,提出了以识别与信号传导原理、分析质量控制与保证原理、分析方法原理与技术、分析技术平台等主要知识模块构成分析化学教学体系的设想,并以教学案例进行了初步的探索。 相似文献
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ICP-AES分析技术的应用研究进展 总被引:5,自引:0,他引:5
ICP-AES分析技术以其快速、准确、灵敏等特点,广泛应用于环境、地矿、冶金、生物、食品、石油、医学检验等领域中的多元素分析,其分析技术和仪器已日益完善,综述了近年来ICP-AES分析技术的应用研究进展,并对其发展前景作了简要的论述与展望。 相似文献
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电致化学发光生物检测技术的新进展 总被引:1,自引:0,他引:1
电致化学发光作为一种分析技术,不仅可用于化学分析,而且正在被越来越多地用于生物检测和传感技术中。随着该分析技术与免疫检测技术生化固定化技术和微细加工技术等的相互融合,电致化学发光生物检测技术具有了更高的精度、分辨率和更广的应用范围。 相似文献
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化学发光分析是利用化学发光反应的发光现象,对化学发光物质由激发态跃迁回基态时发出的光信号进行测量的一种分析方法。化学发光分析具有无需外来光源、灵敏度高、操作方便、分析快速以及易于实现自动化等优点,可与其它分析技术联用,在临床检验、药物分析和环境监测等领域具有广泛应用。近年来,纳米材料、生物芯片及微流控技术的引入促进了化学发光分析技术的发展。本文综述了化学发光分析与高效液相色谱、毛细管电泳、量子点、微流控芯片和微阵列、以及滚环扩增、等温指数扩增和两级等温扩增联用技术的发展,介绍了化学发光分析技术在DNA、生物小分子、生物酶、蛋白质和金属离子检测中的应用研究进展,并展望了其发展趋势。 相似文献
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The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (Asi). In order to document the methylation process in humans, the kinetics of Asi, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of Asi. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As2O3) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of Asi metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of Asi uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems. 相似文献
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Electrochemistry is one of the most advanced techniques for monitoring neurochemical activities in the living brain because electrochemical approaches bear the advantageous features of high spatial and temporal resolutions, which facilitate its tremendous potential in investigating the highly spatially heterogeneous brain system and the fast dynamics of neurochemical activities. On the other hand, since brain is the most complicated organ in the sense of its numerous kinds of neurochemical species, high selectivity is always required for any analytical methods that approach the brain. In this review, we will discuss various electrochemical methodologies to achieve selective detection of neurochemicals in mammalian brain and the strategies developed mainly by our group towards selective monitoring of both electrochemically active and inactive neurochemicals. At the end, we will discuss possible solutions towards brain mapping of neurochemical species and combination of neurochemical detection strategy with electrophysiology as the direction of future development of electroanalysis in living brain. 相似文献
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A. P. Grimanis N. Kalogeropoulos V. Kilikoglou M. Vassilaki-Grimani 《Journal of Radioanalytical and Nuclear Chemistry》1997,219(2):177-185
Neutron activation analysis (NAA) is a very sensitive and accurate multielement analytical method that is widely applied to the investigation of environmental and archaeological problems. The first part of this paper is a review of pollution studies of toxic trace elements in sediments, seawater and marine organisms of Saronikos Gulf, Greece by NAA. The second part of this paper is a review of provenance studies based on minor and trace element research in ancient ceramics, obsidian, flint, limestone, marble and lead by Instrumental NAA, performed at the NCSR Demokritos. 相似文献
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In situ generation of reactive species within confined geometries, such as nanopores or nanochannels is of significant interest in overcoming mass transport limitations in chemical reactivity. Solvent electrolysis is a simple process that can readily be coupled to nanochannels for the electrochemical generation of reactive species, such as H(2). Here the production of hydrogen-rich liquid volumes within nanofluidic structures, without bubble nucleation or nanochannel occlusion, is explored both experimentally and by modeling. Devices comprised of multiple horizontal nanochannels intersecting planar working and quasi-reference electrodes were constructed and used to study the effects of confinement and reduced working volume on the electrochemical reduction of H(2)O to H(2) and OH(-). H(2) production in the nanochannel-embedded electrode reactor output was monitored by fluorescence emission of fluorescein, which exhibits a pH-dependent emission intensity. Initially, the fluorescein solution was buffered to pH 6.0 prior to stepping the potential cathodic of E(0)' for the generation of OH(-) and H(2). Because the electrochemical products are obtained in a 2:1 stoichiometry, local measurements of pH during and after the cathodic potential steps can be converted into H(2) production rates. Independent experimental estimates of the local H(2) concentration were then obtained from the spatiotemporal fluorescence behavior and current measurements, and these were compared with finite element simulations accounting for electrolysis and subsequent convection and diffusion within the confined geometry. Local dissolved H(2) concentrations were correlated to partial pressures through Henry's Law and values as large as 8.3 atm were obtained at the most negative potential steps. The downstream availability of electrolytically produced H(2) in nanochannels is evaluated in terms of its possible use as a downstream reducing reagent. The results obtained here indicate that H(2) can easily reach saturation concentrations at modest overpotentials. 相似文献
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Reactions in droplets in microfluidic channels 总被引:5,自引:0,他引:5
Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights. 相似文献
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