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1.
对受前行化学反应控制的络合吸附催化体系循环叠式方波伏安法进行了理论推导和实验验证,讨论了电流的特性。结果表明,对于络合吸附催化体系的测定,循环叠式方波伏安法的灵敏度比现行方波伏安法高约25倍。  相似文献   

2.
莫金垣  张润建 《分析化学》1995,23(3):255-258
本文提出平行催化体系的对位叠式循环方波伏安法,并对共作了系统的研究,推导了这一方法的催化电流理论方程,并用验验证这理论的正确性,得到其各脉冲电流皆为同方向,对位叠式循环催化电流相当于将电流叠加4次,而波形不受方波幅度大小的影响,因而灵敏度和分辨率有较大提高,优于其它方波伏安法。  相似文献   

3.
研究了络合吸附催化不可逆体系受前行化学反应控制(K<<1)和不受前行化学反应控制(K>>1)两种情况下的循环叠式方波伏安法的电流理论,并进行了实验验证,讨论了电流特性,获得区分K<<1和K>>1的判据。对于上述体系的测定,循环叠式方波伏安法的灵敏度比普通差式采样方波伏安法高一个数理级以上。  相似文献   

4.
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   

5.
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   

6.
推导出受前行化学反应控制的络合吸附不可逆体系叠式循环方波伏安法的电流方程及其各阶导数卷积方程,研究了各峰电流与诸因素的关系,并推导出峰电势表达式。理论推导与实验结果一致。  相似文献   

7.
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   

8.
吸附方波伏库仑法研究:I.简单吸附体系   总被引:1,自引:1,他引:0  
对简单吸附体系方法伏库仑法进行了理论推导和实验验证,讨论了各种因素对伏库仑曲线的影响,研究表明,对于简单吸附体系,方法伏库仑法的灵敏度和检测限均优于方波伏安法。  相似文献   

9.
纳米TiO2电极在不同介质中的电化学行为   总被引:1,自引:0,他引:1  
纳米电极;电催化;纳米TiO2电极在不同介质中的电化学行为;循环伏安法;循环方波伏安法  相似文献   

10.
本文研究了准可逆过程的方波伏安法和作者提出的循环方波伏安法,建立了电流函数理论表示式。理论和实验都表明,循环方波伏安法正向和逆向扫描伏安曲线的峰电势之差(ΔE_p)严格地依存于电极反应的标准速率常数(K_s~-)和电压扫描速度(ΔE/τ)。对于完全可逆过程ΔE_p~-=0随着可逆程度的降低,△E_增加,但不受方波振幅值的影响。引入一个与K_s、ΔE/τ有关的参数K_c,经计算可以得到K_c-ΔE_p理论曲线。由实验得到ΔE_s,从理论曲线查得K_c值,便能估算K_s值。将此法初步应用于测定[Fe(CN)_6]~(3-)-H_2SO_4体系在玻碳电极上的标准反应速率常数,K_s=2.5×10~(-3)cm/s与用阶梯扫描伏安法测得值2.1×10~(-3)cm/s和文献值2.2×10~(-3)cm/s颇为接近。  相似文献   

11.
研究了酚酞在0.5 mol/L氨水-氯化铵缓冲溶液(pH 10)介质中汞膜电极上的电化学行为,并依此建立了酚酞含量的方波伏安法测定.酚酞于-0.98 V(VS.Ag/AgCl)处出现一灵敏的阴极还原峰,峰高与酚酞的浓度在3.0×10-7-5.0×10-5mol/L范围内有良好的线性关系.方法的最低检出限为1.0×10-7mol/L,方法用于酚酞片中酚酞含量的测定,结果满意.  相似文献   

12.
A direct voltammetric method for the rapid determination of butylated hydroxytoluene has been developed. The procedure utilizes a hydrolyzed cellulose acetate film in intimate contact with a glassy carbon electrode and square wave voltammetry. The coated electrode prevents passivation due to adsorption of polymeric oxidation products by way of a size exclusion principle. BHT solutions containing lipid-like surfactants can be analyzed without the need for frequent resurfacing of the electrode.  相似文献   

13.
谢天尧  莫金垣 《分析化学》1993,21(12):1387-1391
本文报道了在不可逆电极过程的强催化体系中,当采用快速方波扫描时,正、逆向电流将出现峰形。依据实验结果,提出了“迁出-进入”的等浓度面理论模型,推导了并讨论了电流方程式。结果表明,文中提出的理论能较好地说明实验结果。  相似文献   

14.
In this work, we designed and manufactured a microfluidic device for isolation and purification of glycoprotein samples. The conceived sample preparation device was fabricated in polycarbonate by micro‐milling. The flow control and the fluid dosage into the micro‐channels was solved by equipping the device with integrated pneumatic valves. The biochemical functionality was provided by beaded support modified by molecules with affinity to glycoproteins which was stacked inside the micro‐channel reminiscent of packed affinity columns used in glycoprotein lectin assays. Unlabeled glycoproteins, namely fetuin, asialofetuin, and prostate‐specific antigen, were voltammetrically analyzed using catalytic peak H at silver amalgam electrode.  相似文献   

15.
A rapid and precise method has been developed for the determination of hydrazine in polyvinylpyrrolidone (PVP). Hydrazine is converted to salicylaldazine by reaction with salicylaldehyde. After extraction, the azine is reduced at –1.56 V versus the SCE at the hanging drop electrode. Detection is accomplished using square wave voltammetry and comparison to an external salicylaldazine standard. The described procedure can detect as little as 70 ng/g hydrazine in PVP.  相似文献   

16.
Determinations of Cu, Fe, Mn and Zn were performed in an oxisol soil treated with effluent originated from a biodigester septic cesspool. The extracts were obtained from a DTPA/TEA (pH 7.3) solution and analysed by electroanalytical methodologies using square wave anodic stripping voltammetry (SWASV) for the analysis of Cu, Mn and Zn and square wave voltammetry (SWV) for Fe analysis, both of them with a thin mercury film microelectrode (ME-Hg). DTPA (diethylenetriaminepentaacetic acid) complexes with Cu, Mn and Fe show electroactivity in the potentials range close to the ones for the free ions in solution, but the Zn complex did not show any electroactivity at the potential range analysed. SWASV/ME-Hg and SWV/ME-Hg results were in good agreement (r2 = 0.996) with the flame atomic absorption spectroscopy (FAAS) analyses, demonstrating that electroanalytical methodologies can be used for micronutrient determinations in soil extracts without serious interferences of the matrix components. Some characteristics of the complex formed between DTPA-metals are explored by EPR experiments.  相似文献   

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