常压微等离子体阳极与离子溶液界面的电荷转移反应

常压微等离子体电极是一种有望取代常用贵金属电极用于电化学反应的气体电极. 然而目前关于微等离子体阳极与离子溶液界面反应的研究及其用于金属电沉积的报道还较少. 本文使用常压微等离子体作为阳极, 通过紫外-可见吸收光谱监测阳极电解液中亚铁氰化钾被氧化生成的铁氰化钾的含量, 发现铁氰化钾的含量随放电时间的延长而增加, 并且其增加的速率与放电电流成比例. 在放电结束后, 随着放置时间的延长铁氰化钾的含量继续升高, 其升高的速率与放电时间的长短有关. 放电结束后铁氰化钾含量的增加速率远小于放电时的增加速率. 实验结果表明微等离子体电极可以作为气体阳极在等离子体和液体界面进行电荷传输, 并引发电化学反应, 同时在放电的过程中产生了氧化活性物质. 在饱和硫酸铜溶液中, 使用微等离子体阳极可以在不锈钢阴极上进行铜的电沉积, 电流效率达到90%.     

微等离子体发射光谱技术的研究进展

微等离子体是被限制在一个有限空间范围内的等离子体,其作为一种新型激发源具有能耗低、体积小、价格低等优点,在发射光谱仪器的微型化发展中展现了巨大的应用潜力。该文介绍了近年来基于微等离子体激发源构建的发射光谱(OES)系统在分析化学领域中的新应用。目前,微等离子体OES系统不仅能够直接测定气相或液体中的分析物,还可与气相色谱(GC)、化学蒸气发生(CVG)、电热蒸发(ETV)、微电渗析(μED)、毛细管电泳(CE)等多种技术联用,极大地扩展了该系统的应用范围。而提高微等离子体本身的激发能力,选择合适的进样方式,有望使微等离子体OES系统的性能得到进一步的提升。同时,相关仪器设备的开发将为痕量元素的现场分析提供可靠的手段。     

Biparametric Potentiometric Analytical Microsystem Based on the Green Tape Technology

The construction and evaluation of a Low Temperature Co‐fired Ceramics (LTCC)‐based microsystem prototype as a possible on‐site microanalyzer to monitor the presence of two ions in water simultaneously is presented. The approach has been assayed to detect nitrate and chloride ions as model analytes by means of integrating in the same single substrate an ion selective polymeric membrane to nitrate and two screen‐printed Ag/AgCl electrodes. One supplies the chloride ion concentration and the other is to complete the potentiometric detection system as the reference electrode. The results obtained by the full characterization of the microanalyzer prove the relevance of the proposal and the possibility to be transferred to real‐world samples and environmental monitoring.     

Microplasma electrochemistry (MIPEC) strategy for accelerating the synthesis of metal organic frameworks at room temperature

Metal organic frameworks(MOFs) are a kind of promising materials in many applications,while the fast and controllable synthesis of MOFs is still challenging.Here,taking HKUST-1 as illustration,a microplasma electrochemistry(MIPEC) strategy was developed to accelerate the synthesis process of MOFs with micro-plasma acting as cathode.Treating the HKUST-1 precursor solution with micro-plasma cathode could not only transfer the electrons into the solution leading to the deprotonation effect,but also generate radical species to trigger and accelerate the nucleation and growth of MOFs at the plasmaliquid interface.Thus,uniform and nanosize MOFs could be prepared within minutes.The obtained MOFs show similar excellent uranium adsorption properties compared with those obtained by other method,with a highly adsorption capability of uranium with 550 mg/g in minutes.The novel MIPEC strategy developed in this work provides an alternative for controllable synthesis of MOFs,and especially has potential application in accelerating traditional organic synthesis.     

Photoconductive UV Detectors Based on ZnO Films Prepared by Sol-Gel Method

Highly c-axis oriented ZnO thin films were deposited on single crystal Si (111) substrates by sol-gel method. The photoconductive UV detectors based on ZnO thin films, being a metal-semiconductor-metal (MSM) structure with interdigital (IDT) configuration, were fabricated by using Au as contact metal. The characteristics of dark and photocurrent of the UV detector, the UV photoresponse of the detector were investigated. The linear current-voltage (I-V) characteristics under both forward and reverse bias exhibit ohmic metal-semiconductor contacts. Under illumination using monochromatic light with a wavelength of 365 nm, photo-generated current arrived at 44.89 μ A at a bias of 6 V. The detector exhibits an evident wide-range spectral responsivity and shows a trend similar to that in photoluminescence (PL) spectrum. PL spectrum of detector exhibits two peaks, one is the near band edge emission, and another is the deep-level emission in the visible region.     

Some trends in the development of microplasmas for spectrochemical analysis

The development of microplasmas for spectrochemical analysis by optical methods is discussed. Recent achievements in miniaturization are highlighted, especially for three types of plasmas, namely high-frequency plasmas, dc-discharges and microwave plasmas. The potentials of each of these groups of plasmas as sources for atomic emission spectrometry are discussed. Literature citations and experiments indicate that the plasmas are also very useful as atom reservoirs for atomic absorption spectrometry. Methods of sampling, including feeding with gas chromatography effluents, the use of electrothermal vaporization, and the evolution of gaseous species (as shown for the case of Hg vapor), are discussed as prominent interfaces to make use of these sources for elemental analysis.     

A Bipotentiostat for Four-Electrode Electrochemical Detectors

Abstract

The design and operation of a double or bipotentiostat used to independently cont.ro1 the potential and measure the current produced at two working electrodes in a four-electrode thin-layer electrochemical detector, is described.     

钙钛矿阵列化组装及其多功能探测器的应用

钙钛矿材料优异的光电性能使其在高集成、 高性能、 多功能光电探测领域具有广泛的应用前景. 近年来, 科研人员致力于钙钛矿阵列化探测器的研究, 并取得了一系列重要的成果. 本文重点评述了钙钛矿材料的阵列化及其多功能探测器的制备和应用, 介绍了钙钛矿材料的结构分类、 阵列化集成方法及光电探测器的基本器件类型和性能指标, 并进一步阐述了基于钙钛矿一维阵列的高性能光电探测器及其多功能探测器的相关应用研究进展. 最后, 对该研究领域未来的发展方向进行了总结和展望.     

质谱匹配概率方法及结果可靠性评价

质谱匹配概率方法不仅能提供纯样品的分析结果,而且也能区分混合物中的成分。因而为大大提高对质谱数据的分析能力提供了可能性,并扩大了它在有机物鉴定方面的应用。本文介绍该方法作环境空气中有机物质谱分析及与综合控制系统资料的比较,并以美国标准局的标准参考数据库作比较。同时讨论了该方法的优点和不足     

A sensitive and compact mercury analyzer by integrating dielectric barrier discharge induced cold vapor generation and optical emission spectrometry

An environmentally friendly,low power consuming,sensitive and compact mercury analyzer was developed for the determination of mercury in water samples by integrating a thin film dielectric barrier discharge induced cold vapor reactor and a dielectric barrier discharge optical emission spectrometer into a small polymethyl methacrylate plate(10.5 cm length×8.0 cm width×1.2 cm height).Mercury cold vapor was generated when standard or sample solutions with or without formic acid were introduced to the reactor to form thin film liquid and exposed to microplasma irradiation and subsequently separated from the liquid phase for transport to the microplasma and detection of its atomic emission.Limits of detection of 0.20 μg L~1 and 2.6 μg L~1 were obtained for the proposed system using or not using formic acid,respectively.Compared to the conventional microplasma optical emission spectrometry used for mercury analysis,this system not only retains the good limit of detection amenable to the determination of mercury in real samples,but also reduces power consumption,eliminates the generation of hydrogen and avoids the use of toxic or unstable reductant.Method validation was demonstrated by analysis of a certified reference material of water sample and three real water samples with good spike recoveries(88-102%).     

气相色谱用氦等离子体离子化检测器研究进展

本文对用于气相色谱的直流放电等离子体、微波等离子体和脉冲放电等离子体等三种等离子体离子化检测器进行了评述。对气相色谱用等离子体离子化检测器的发展前景进行了展望。     

微小型氢火焰离子化检测器及在色谱中的应用

构建了一种微小型氢火焰离子化检测器(μ-FID).与传统FID不同,助燃空气从收集极上部侧面导入,沿收集极与检测器壳体之间的缝隙向下流动,以环状气流沿壁流入燃烧室,流向反转后从中空的收集极内流出.火焰喷口位于燃烧腔的正中心轴线上,该区域助燃气的流动非常稳定,因此噪音电平非常低.采用更高的极化电压以提高离子化效率.对喷口...     

用于高效毛细管电泳的电化学检测器

阐述了高效毛细管电泳电化学检测器（包括电导、电势和安培检测）的研究现状，重点是检测器的研制及接口的制作技术。对各种电化学检测器的应用情况也进行了总结。展望了高效毛细管电泳电化学检测的发展前景。     

Determination of Toxic Organophosphorus Compounds by Specific and Nonspecific Detectors

Abstract

Sample preparation procedures and gas chromatography methodology are presented for the determination of tabun, sarin, soman, and VX in aqueous solutions. Extraction recoveries from chloroform were quantitative. Peak area ratios of organophosphorus compounds (OPs) to internal standard versus concentrations of OP were linear over the range of 10-1000 (μg/ml when determined by the flame ionization detector and 10-800 μg/ml when determined by the flame photometric detector. Imprecision occurring at low ng concentrations of VX was caused by its adsorption on the analytical column. Acceptable precision was regained by the addition of a weak base, such as atropine, to the sample extract prior to its injection onto the gas chromatograph (GC).     

微全分析系统检测方法的研究进展

综述了不同类型的检测方法在微全分析系统的应用，并简述了各类型的检测方法的优缺点。引用文献92篇。     

微小型氢火焰离子化检测器及在色谱中的应用

构建了一种微小型氢火焰离子化检测器(μ-FID).与传统FID不同,助燃空气从收集极上部侧面导入,沿收集极与检测器壳体之间的缝隙向下流动,以环状气流沿壁流入燃烧室,流向反转后从中空的收集极内流出.火焰喷口位于燃烧腔的正中心轴线上,该区域助燃气的流动非常稳定,因此噪音电平非常低.采用更高的极化电压以提高离子化效率.对喷口材料及其内径、收集极长度、收集极至喷口的距离等结构参数进行了优化.在最优条件下,极化电压800 V时,检测器的信噪比比极化电压为150 V时提高一个数量级以上,检出限达1×10-12 g/s.相对于常规FID,μ-FID的气体消耗降低了70%,仅需要氢气和空气两种气体;具有体积小、重量轻、结构简单、灵敏度高、成本低廉等优点,适合作为便携式微型色谱的通用型检测器.     

电荷注入检测器—端视等离子体原子发射光谱中分析动态范围

实验研究了电荷注入检测器－端视电感耦合等离子体光谱中分析动态范围，测量了ＡＬ，Ｂ、Ｂｅ，Ｃｄ，Ｃｕ，Ｃｏ，Ｆｅ，Ｌｉ，Ｓｒ，Ｖ，Ｋ，Ｓｒ等１２个元素的不同光谱级次的４４条分析工作曲线。结果表明，分析范围为４－５个数量级，无明显自吸收，Ｌｏｍａｋｉｎ公式的自吸收系数ｂ＝１，说明在ＣＩＤ－ＡＶＩＣＰ光谱中有较宽的分析动态范围 。     

Determination of Bioactive Components of Cistanche deserticola (Roucongrong) by High-Performance Liquid Chromatography with Diode Array and Mass Spectrometry Detectors

Cistanche deserticola (Orobanchaceae) has been widely used in China for food and medicinal purposes. Chemical differentiation between the raw and steamed C. deserticola was performed by high-performance liquid chromatography coupled with diode array detection and mass spectrometry. Eight chemicals (echinacoside, cistanoside A, acteoside, cistanoside C, 2′-acetylacteoside, isoacteoside, isocistanoside C, and tubuloside B) were obtained from raw and steamed C. deserticola, and the kinetics in the steaming process were investigated in detail. When the steaming time increased, the concentrations of echinacoside, cistanoside A, acteoside, cistanoside C, and 2′-acetylacteoside decreased, while the levels of isoacteoside, isocistanoside C, and tubuloside B increased. Furthermore, two compounds, 5-hydroxymaltol and 5-hydroxymethylfurfural, were found only in the steamed form. In addition, hierarchical clustering analysis and principal component analysis were performed to evaluate the classify the chemical concentrations among steamed C. deserticola. The results showed that steaming had a significant influence on the chemical constitution. The study provide chemical analysis of raw and steamed C. deserticola, including possible transformation pathways, and should allow better understanding of the steaming process of this herb.     

液相色谱仪检测器新规程的检定方法与特定条件汇总

介绍新版本液相色谱仪检定规程(JJG 705–2014)中3种变动较大检测器的检定方法,如荧光检测器、示差折光率检测器、蒸发光散射检测器。对检定不同厂家检测器设定的特定检定条件进行了汇总。