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可逆,准可逆和不可逆表面反应循环伏安法的数字模拟   总被引:1,自引:0,他引:1  
用数字模拟的方法研究了可逆、准可逆和不可逆表面反应的循环伏安法响应,与理论推导结果相一致,但数字模拟提供了更灵活、方便、通用性更强的研究表面反应机理的手段,本文建立了有关的数字模型,给出了不同动力学参数条件下的电流-电位关系曲线,讨论了动力学参数对电流函数的影响以及用于测定这些参数的方法。  相似文献   

3.
采用数字模拟法对耦联酶催化反应体系的表面循环伏安行为进行了研究,讨论了介体氧化还原动力学、酶催化动力学及介体催化酶动力学等参数对循环伏安图的影响,并用实验进行了验证。  相似文献   

4.
邓兆祥  林祥钦 《分析化学》2000,28(8):930-935
使用指数扩展的网络方法对电活性物质吸附与扩散共存的电化学体系进行了模拟,包括吸附为平衡和非平衡态的情形,所得结果跟文献报道一致并有所补充。该方法具有简便、直观、灵活性强等优点。  相似文献   

5.
对位叠式循环方波伏安法:Ⅰ.简单可逆电极体系   总被引:3,自引:0,他引:3  
莫金垣  蔡沛祥 《分析化学》1995,23(3):250-254
本文提出叠式循环方波伏安法和对位叠式循环方波伏安法,对简单可逆电极体系的理论作了推导和验证,经对各种电流的比较,发位叠式循环方波伏安法有较多的优点。较之其它方波伏安法灵敏。  相似文献   

6.
叠式循环阶梯脉冲伏安法:Ⅰ.简单可逆电极体系   总被引:1,自引:0,他引:1  
本文提出循环阶梯脉冲伏安法和对位叠式循环阶梯脉冲伏安法,推导出简单可逆电极体系的电流方程,研究了峰电流与诸因素的关系,并进行了实验验证,发现对位叠式循环阶梯脉冲伏安法有较多的优点  相似文献   

7.
推导出不受前行化学反应控制的络合吸附不可逆过程叠式循环方波伏安法的电流及其卷积和导数方程,系统地研究了各电流峰形,各峰电流与有关参数的关系,给出了峰电势表达式,并进行了实验验证。该理论同样适用于简单吸附不可逆过程。  相似文献   

8.
吕荣山 《分析化学》1998,26(3):359-365
对超微电极快速循环伏安法作了综述。讨论了该法的主要原理、特点和仪器关键性部分。并扼要介绍其主要应用。  相似文献   

9.
推导出不受前行化学反应控制的络合吸附不可逆过程叠式循环方波伏安法的电流及其卷积和导数方程,系统地研究了各电流一有关参数的关系,给出了峰电势表达式,并进行了实验验证。该理论同样适用于简单吸陵不可逆过程。  相似文献   

10.
用循环伏安法研究了N,N-二乙基对苯二胺,N,N,N′,N′-四乙基对苯二胺,N,N-二乙基氨基酚三类化合物的电化学氧化及其氧化产物的后继化学反应,求算了脱氨反应速率常数,揭示了苯环上甲基取代基和氮原子上不同取代基对脱氨反应的影响。 脱氨反应为OH-或水进攻醌亚胺的亲核反应。由于甲基的斥电子效应,当苯环上引进甲基取代基时,环上负电荷增大,带正电荷的醌亚胺趋于稳定,水解反应速度减慢。 苯环上引进二个甲基取代基,其相应的苯胺化合物的半波电位下降大约120mV。二乙基对苯二胺的苯环上每引进一个甲基取代基,其氧化产物与彩色成色剂偶合生成的染料的吸收峰向长波方向移动20-30nm。  相似文献   

11.
化学修饰电极循环伏安法的数值模拟   总被引:1,自引:0,他引:1  
许可  吴守国 《分析化学》1999,27(12):1442-1445
用CN法对化学修饰电极(CME)的循环伏安法(CV)进行了数值模拟。建立了CME的有限扩散理论模型,引入了活度系数比、扩散系数校正因子及动力学参数等。模拟的普鲁士兰(PB)修饰电极与文献相符很好。  相似文献   

12.
氨基比林的循环伏安测定及其电化学行为研究   总被引:1,自引:0,他引:1  
在0.05 mol/L Tris-HCI(pH=8.5)的底液中,采用循环伏安法测定氨基比林,得到一良好的氧化峰,峰电位Ep=0.25 V,峰电流Ip与氨基比林的浓度在8.0×10-7~1.6×10-5mol/L范围内呈线性关系,相关系数r=0.9969,检出限为9.0×10-8mol/L.采用本法测定安痛定注射液中氨基比林的含量,回收率在95.0%~106.2%相对标准偏差(RSD)为1.68%.研究了氨基比林在玻碳电极上的电化学行为,结果表明氨基比林的电极过程具有吸附性和不可逆性.  相似文献   

13.
《Analytical letters》2012,45(15):2369-2379
Metalloenzymes that carry a pterin-based molybdenum cofactor in their center catalyze numerous reactions in the human body and play a crucial role in its metabolism. Specifically, these enzymes promote redox reactions and oxygen transport in the body. Their absence may cause many problems leading to disability or even death in early childhood. Therefore, model compounds need to be synthesized and analyzed to investigate the reactivity, redox potential, and geometry of these cofactors. This study focused on electrode processes and determined the redox potentials of the new bis-(4-mercapto-5-(p-tolyl)-3H-1,2-dithiole-3-thione)-dioxomolybdenum complex by cyclic voltammetry. The 4-mercapto-5-(p-tolyl)-3H-1,2-dithiole-3-thione ligand underwent irreversible oxidation and reduction at thiol and thione functional groups. The new dioxomolybdenum complex showed a quasi-reversible two-stage electrode process.  相似文献   

14.
The electrochemical oxidation of catechols ( 1 ) have been studied in the presence of diaza‐18‐crown‐6 (DA18C6) ( 3a ), diaza‐15‐crown‐5 (DA15C5) ( 3b ), and aza‐15‐crown‐5 (A15C5) ( 3c ) as nucleophiles in aqueous solution, by means of cyclic voltammetry and controlled‐potential coulometry. The results indicate the participation of electrochemically generated o‐benzoquinones ( 2 ) in Michael‐type reaction with aza‐crown ethers ( 3 ) to form the corresponding new o‐benzoquinone‐aza‐crown ether adducts ( 5 ). Based on ECE mechanism, the observed homogeneous rate constants (kobs) of the reaction of o‐bezoquinones ( 2 ) with aza‐crown ethers ( 3 ) were estimated by comparing the experimental cyclic voltammograms with the digital simulated results. The calculated observed homogeneous rate constants (kobs) was found to vary in the order DA18C6>DA15C5>A15C5.  相似文献   

15.
研究了抗癌药物冬凌草甲素在悬汞电极上的电化学行为。在NaAc-NaOH(pH 7.8)的缓冲溶液中,冬凌草甲素有一受吸附控制的还原峰,峰电位为-1.150 V,峰电流与冬凌草甲素浓度在7.25×10-7~1.01×10-5mol/L范围内有良好的线性关系,检出限为1.45×10-7mol/L(S/N=3)。对冬凌草片剂实际样品中冬凌草甲素含量测定,结果满意。  相似文献   

16.
《Analytical letters》2012,45(15):2691-2700
Abstract

The voltammetric behaviour of minocycline at a water/nitrobenzene interface has been studied by normal, semi-differential and semi-integral cyclic voltammetry. The semi-differential cyclic voltammetry can be used as a rapid, simple method for determination of the antibiotic minocycline in the range of 5–200 ug/ml and the relative standard deviation is within 3%. Drug samples were analyzed and satisfactory results were found as compared with US Pharmacopoeia method.  相似文献   

17.
《Analytical letters》2012,45(8):1339-1357
Abstract

An amperometric enzyme electrode for the determination of glucose (<16mmol?1) is constructed by incorporating electron mediators tetrathiafulvalene in Nafion and subsequently coating with immobilized glucose oxidase. The results obtained from measurements of glucose in fermentation samples containing biomass or molasses indicate the utility of the electrode for glucose assay in such media over at least 12 weeks. Digital simulation is employed to study the cyclic voltammetry (CV) of Tetrathiafulvalene-Glucose Oxidase-Modified Glassy Carbon Electrode (TTF-GOD-GCE); the digital model is built and the effects of kinetic parameters on CV-curves are discussed. The response process of the Tetrathiafulvalene-Glucose Oxidase-Modified Electrode is partly explained by the simulation results and further research is expected to guide the design of biosensors and improve the properties of the enzyme-mediator modified electrode.  相似文献   

18.
采用循环伏安法研究了大黄素在滴汞电极上的电化学行为,应用线性扫描法提出了药用植物大黄中大黄素不需分离的直接测定方法。大黄素在pH 5.72 B-R缓冲溶液中,在-0.434 V(vs.Ag/AgCl)处产生一灵敏的极谱峰,峰电流与大黄素浓度在1×10-6~1.5×10-5mol.L-1范围内呈线性关系。试验结果表明:该体系属具有吸附性的准可逆过程体系。  相似文献   

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