共查询到20条相似文献,搜索用时 93 毫秒
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本文探讨了盐酸介质中,聚苯胺在超微电极上的伏安性质,峰电流(ip)a与聚合电量、扫描速率等关系,在Qp较小时,具有薄膜电极特性,Qp很大时峰电流受扩散控制。 相似文献
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本文推导了超微带电极上准稳态过程可逆波及其微分、半微分伏安曲线方程式,对曲线的性质进行了详细的讨论。在K4Fe(CN)6·KCl体系中用超微金带电极对理论进行了验证,结果表明,理论与实验相符。 相似文献
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张祖训 《高等学校化学学报》1993,14(1):21-24
本文提出了超微盘电极上电位溶出分析法理论,内容包括:过渡时间(τ)方程式、电位(E)-时间(t)曲线方程式及微分电位溶出分析法dt/dE-E曲线方程式,并对该曲线的性质进行了论述。 相似文献
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本文用苯醌在Mcllvaine缓冲溶液(pH=7.0)中的电化学可逆还原反应体系验证了超微半扁球电极上的稳态电流方程式,理论与实验结果相符,超微半扁球汞电极用电镀法制备。 相似文献
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超微盘电极上苯胺的循环扫描伏安法电化学聚合 总被引:1,自引:0,他引:1
本文对超微盘电极上苯胺的循环扫描伏安法电化学聚合进行了研究。对研究过程的伏安曲线性质以及峰电流和单体浓度,循环扫描次数和速率及电位之间的关系作了详细的探讨,还给出了峰电流的经验式。 相似文献
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计算机化的多功能超微电极电化学仪器 总被引:4,自引:1,他引:3
报道了一种计算机化的多功能超微电极电化学仪器.它具有12种基本功能和正确的电流、电位性质及很高的灵敏度.能用于超微电极的电化学研究和测试,也适用于常规电极. 相似文献
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本文在阐述超微电极技术相关原理的基础上,总结了超微电极的特点、类型及研究方法,综述近十年来超微电极的制备与应用进展,并介绍了超微电极的发展现状。 相似文献
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超微电极研究—电迁移对准稳态线性扫描伏安法的影响 总被引:4,自引:0,他引:4
提出了受电迁移影响且适用于超微盘电极的准稳态线性扫描伏安电流方程,考察了各种价态的离子在不同浓度的支持电解质中电迁移对伏安曲线的影响,并将实验结果与理论进行了比较讨论。 相似文献
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《Electroanalysis》2006,18(10):947-954
In this work, for the first time a fast continuous cyclic voltammetry was used as a highly sensitive detection method for Penicillin G in a flow‐injection system. A special computer‐based numerical calculation method (using Fast Fourier Transformation) is introduced here for enhancing the analyte signal and noise reduction. During the measurements, the potential waveform (consists of potential steps for cleaning, stripping and potential ramp) was continuously applied on an Au disk microelectrode (with a radius 12.5 μm in radius). The stripping time was less than 200 ms. Effects of rest potential, sweep rate, and delay time on the sensitivity of the method were investigated. The limit of detection of the method was 1.0 × 10?11 M. The detection limit of the method is 660 times lower than the most sensitive reported method. The relative standard deviation of the method at 1.0×10?7 M of Penicillin G was 2.7% for 10 runs. 相似文献
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《Electroanalysis》2006,18(17):1703-1709
A simple bipartite expression for transient amperometric currents at a membrane covered planar electrode has been derived. This expression is uniquely applicable across the entire measurement time frame and enables a rapid, comprehensive dynamic simulation of solute diffusion through the membrane barrier. The effective diffusion coefficient through the membrane for an electrochemically active solute can be readily obtained by employing the simple curve fitting routine. The diffusion coefficients for 4‐acetaminophenol through 0.05 and 0.025 μm pore diameter mixed cellulose esters membranes were determined to be 1.96×10?7 and 1.21×10?7 cm2/s, respectively. For catechol respective values were 1.55×10?7 and 1.15×10?7 cm2/s. Diffusion coefficients were reduced following membrane exposure to bovine serum albumin and this change provided a functional counterpart to conventional structural measures of surface biofouling. The approach has relevance to both sensors and membrane separation systems in biomedicine, and has the potential to offer a rapid assessment of membrane surface biofouling. 相似文献
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Recent progress in the application of chitosan and its derivatives in analytical chemistry, especially their application in the field of separation science including as capillary coating materials, chromatographic column fillings, and adsorption materials, during the past 8 years is reviewed. 相似文献
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中医药现代化对分析化学的机遇与挑战 总被引:3,自引:0,他引:3
综述了多种分析方法在中医药现代化中的重要作用,内容包括中药面临的机遇与挑战,中药市场及所存在的问题,当前在中药鉴别、分离、提纯以及复方药效的研究常用的分析方法,中药指纹图谱以及残留农药的检测。引用文献183篇。 相似文献
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Werner Stumm Ren Schwarzenbach Laura Sigg 《Angewandte Chemie (International ed. in English)》1983,22(5):380-389
The development of cultural and technical civilization has been marked with increasing interference in hydrogeochemical cycles and the production of a growing number of chemicals; this is accompanied by a growing concern on the potential adverse effects of chemicals on biological systems. Assessment of the potential toxicological and ecological effects of pollutants is of central importance. We are of the opinion that this cannot be accomplished by merely evaluating the harmfulness of a substance on the basis of toxicity tests with individual organisms and by monitoring analytically the environment for pollutants. We would like to encourage chemists to participate in the solution of ecotoxicological problems: chemodynamical concepts permit the estimation-on the basis of physical-chemical generalizations and with the help of compound-specific data-of the fate, the distribution, the potential for bioaccumulation in the food chain, and the approximate residence time of pollutants (and thus the attainable residual concentrations) in the environment and therefore to predict the relative risk of different pollutants. 相似文献
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《Analytical letters》2012,45(5):771-785
Abstract Current-potential response of a small interface formed between two immiscible solutions of electrolytes is examined. The diameter of the contact area made in a thin glass wall separating two solvents is approximately 130 μm. Ion transport across the nitrobenzene-water interface is studied by addition of probe semi-hydrophobic ions such as tetramethylammonium, tetraethylammonium, picrate, choline and dodecylsulfate to either aqueous or nonaqueous phase. The voltammetric behavior observed with the microinterface generally resembles that of a solid microelectrode of a similar radius. The contribution of ohmic drop becomes less significant with decrease of the interface area. This phenomenon permits voltammetric and amperometric measurements without using a potentiostat, and the solvent resistance is of a lesser problem. 相似文献
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Norouzi P Ganjali MR Daneshgar P Dinarvand R Moosavi-Movahedi AA Saboury AA 《Analytica chimica acta》2007,590(1):74-80
In this work a novel method for the fast monitoring of lidocaine in flow-injection systems has been developed. The fast Fourier transform continuous cyclic voltammetry (FFTCV) at gold microelectrode in flowing solution system was used for determination of lidocaine in its pharmaceutical formulation. The presented technique was very simple, precise, accurate, time saving and economical, compared with all of the previously reported methods. The recommended technique demonstrated some advantages over other reported methods. Firstly, there was no need for the oxygen removal from the test solution. Secondly, a picomolar detection limit was achieved, and additionally, the method was fast enough for the determination of any such compound, in a wide variety of chromatographic methods. The method was linear across the concentration range of 240-1.1 × 105 pg mL−1 (r = 0.996) with a limit of detection and quantitation 117.3 and 240 pg mL−1, respectively. As a conclusion this system offers the requisite accuracy, sensitivity, precision and selectivity to assay lidocaine in injections. 相似文献
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Mi-Kyung Bahng Calvin Mukarakate David J. Robichaud Mark R. Nimlos 《Analytica chimica acta》2009,651(2):117-101
Pyrolysis and gasification are two of the more promising utilization methods for the conversion of biomass toward a clean fuel source. To truly understand and model these processes requires detailed knowledge ranging from structural information of raw biomass, elemental composition, gas-phase reaction kinetics and mechanisms, and product distributions (both desired and undesired). The various analytical methods of biomass pyrolysis/gasification processing are discussed, including reactor types, analytical tools, and recent examples in the areas of (a) compositional analysis, (b) structural analysis, (c) reaction mechanisms, and (d) kinetic studies on biomass thermochemical processing. 相似文献