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1.
罂粟碱的吸附伏安行为的研究   总被引:3,自引:0,他引:3  
曾泳淮  张光润 《分析化学》1995,23(10):1137-1142
在NH3-NH4Cl底液中,罂粟碱在汞电极上有一一线性扫描还原峰,峰电位Epc=-1.44(vs.sat.Ag/AgCl)。该峰具有明显的吸附性。当PAP浓度较小时,扫速较快,搅拌富集时间较长时,电极反应完全为吸附态的PAP的还原所控制。  相似文献   

2.
王桂芬  朴元哲 《分析化学》1998,26(12):1490-1493
应用循环伏安法、微分脉冲伏安法对多菌灵在破碳电极上的电化学行为及其测定进行了研究。在pH=9.0的2mol/L NH3-NH4Cl底液中,对其进行循环伏安扫描,发现于0.61V(vs.Ag/AgCl)产生一灵敏的氧化峰。微分脉冲伏安法殉菌灵的检测限为4×10^-8mol/L。多菌灵的浓度在5.0×10^-7 ̄1.0×10^-5mol/L间与微分脉冲伏安峰电流呈线性关系(r=0.9942)。对于1×  相似文献   

3.
秋水仙碱在碳糊电极上的吸附伏安行为   总被引:6,自引:1,他引:6  
于素华  冷宗周 《分析化学》1997,25(10):1217-1220
秋水仙碱在硫酸溶液中加热水解得分析试液。在0.05mol/LH2SO4底液中,用碳糊电极吸附伏安法测定秋水仙碱,阳性峰电位为0.82V(vs.SCE),峰电流与秋水仙碱的浓度在1.0×10^-7~1.0×10^-4mol/L范围内呈良好线性关系,检测下限为5.0×10^-8mol/L回收范围为95.0%~103.5%RSD为2.8%(n=10)。本对反应机理进行了初步探讨。  相似文献   

4.
吸附伏安法测定中草药中的钼   总被引:2,自引:0,他引:2  
叙述了测定痕量钼的一种灵敏的吸附伏安法。本法以钼(Ⅵ)和茜素红络合物在悬汞电极上的吸附行为为基础,在0.01mol/LNaAc、0.08mol/LHAc和1.5×10-6mol/L茜素红底液条件下,该体系1.5、2.5阶微分吸附伏安法的线性范围是7.5×10-11~7.5×108mol/L;对2.5阶微分吸附伏安法,富集3min的检测下限是5×10-11mol/L。用此法直接测定了中草药中的痕量钼。  相似文献   

5.
示差脉冲伏安法测定黄酒中的酪氨酸   总被引:3,自引:0,他引:3  
本文研究了硼砂介质中镍与酪氨酸络合物的示差脉冲吸附伏安特性,实验了仪器参数对示差脉冲阴极吸附伏安法的影响,在最佳条件下络合物峰电流与酪氨酸浓度在2.0×10^-7~4.0×10^-5mol.L^-1范围内有线性关系,并以此法测定了黄酒中酪氨酸的含量。  相似文献   

6.
林祥钦  赵炜 《分析化学》1999,27(2):237-241
报道一种双铂盘工作电极、相应的毛细管参比电极和竖直工电化学池设计并用于快速循环伏安测量。双工作电极包括一个常规工作电极,一个辅助工作电极。后者在使用中接地,仅提供参比电位来控制工作电极的电位。参比毛细管尖端安设在接近辅助工作电极的位置上;用0.3mm直径Pt盘工作电极,在电位扫描速度高达10kV/s都可以得到类似于100%iR补偿的伏安曲线,而不必使用iR补偿电路。本文围绕高扫速伏安法中工作电极电  相似文献   

7.
研究了脱氧核糖核酸的极谱伏安行为,在0.1mol.L^-1NH4Cl溶液中DNA产生一良好的极谱峰,峰电位Ep=-1.65V(vs.Ag/AgCl),且峰电流ip与DNA的浓度在4.5*10^-5-3.7*10^-4mol.LO^-1范围内呈线性关系,可望用于DNA的定量分析。  相似文献   

8.
头孢噻肟钠的降解及其产物伏安行为的研究   总被引:18,自引:1,他引:18  
头孢噻肟钠在NaOH溶液中降解后,于0.1mol/LNaOH中得一灵敏的吸附伏安原峰,Ep=-0.78V(νsAg/AgCl),ip与头孢噻肟钠浓度在1.0×10^-^9-1.0×10^-^8,1.0×10^-^8-1.0×10^-^7,1.0×10^-^7-1.0×10^-^6mol/L范围内呈线性关系,检出限为5.0×10^-^1^0mol/L。用多种电化学手段研究其降解产物的伏安行为,测定了  相似文献   

9.
自从1990年用电弧法成功地制备出宏观量的C60和C70以来,富勒烯的电化学研究有了迅速的发展.理论研究指出,在一个C60簇化合物中,有六个吡喃环烯单元,可分别得到一个电子使五元环芳香化,从而形成C(n=1~6)阴离子.Haufler首先报导了C60可逆的两步单电子还原,之后一些作者陆续得到了三步、四步和五步单电子电还原过程.直到达1992年,在使用混合溶剂并控制低温-10℃至5℃和-88℃至60℃条件下,才得到了C60的六步电还原伏安图.富勒烯的微电极伏安法的研究极少见报导.杨汉西等用铂微电极得到了C60三步电还原的稳态伏安图.本文在…  相似文献   

10.
2.5次微分溶出伏安法测定茶叶中痕量锌   总被引:4,自引:0,他引:4  
本报告了测定痕量锌的一种新方法,在0.01mol/LHAc-0.01mol/LNaAc溶液中,锌和乙醛酸缩氨基硫脲形成的配合物产生一个很灵敏的还原峰,峰电位是一-0.82V(vs.SCE),锌的浓度在2.0×10^-8-8.0×10^-7mol/L范围内与峰高呈直线关系,检测限是6.0×10^-9mol/L,该方法用于测定茶叶中痕量锌,结果令人满意。  相似文献   

11.
The importance of reliable detection systems for enantiomeric assays increases with the necessity of high throughput screening analysis of raw materials for the pharmaceutical industry. The utilization of electrochemical sensors in enantioselective analysis is an accurate and precise alternative to chromatographic techniques. The reliability of the response characteristics as well as of the analytical information obtained by using electrochemical sensors is strictly correlated with the design of the sensors. The designs evaluated for sensors have been based on PVC, imprinting polymers and carbon paste matrices. Among these, carbon paste sensors have been the most reliable and have been utilized for the construction of potentiometric, enantioselective membrane electrodes as well as for amperometric biosensors, and immunosensors. There are two ways to use the electrochemical sensors in enantioselective screening analysis: selective binding and catalyst selectivity. A molecule with a special chemical architecture is required for selective binding: a lock for a key. The high reliability of analytical information obtained using these sensors has made possible the automation of potentiometric and amperometric techniques by integration of enantioselective sensors as detectors in flow injection analysis and sequential injection analysis techniques.  相似文献   

12.
Detection of relevant contaminants using screening approaches is a key issue to ensure food safety and respect for the regulatory limits established. Electrochemical sensors present several advantages such as rapidity; ease of use; possibility of on-site analysis and low cost. The lack of selectivity for electrochemical sensors working in complex samples as food may be overcome by coupling them with molecularly imprinted polymers (MIPs). MIPs are synthetic materials that mimic biological receptors and are produced by the polymerization of functional monomers in presence of a target analyte. This paper critically reviews and discusses the recent progress in MIP-based electrochemical sensors for food safety. A brief introduction on MIPs and electrochemical sensors is given; followed by a discussion of the recent achievements for various MIPs-based electrochemical sensors for food contaminants analysis. Both electropolymerization and chemical synthesis of MIP-based electrochemical sensing are discussed as well as the relevant applications of MIPs used in sample preparation and then coupled to electrochemical analysis. Future perspectives and challenges have been eventually given.  相似文献   

13.
Bacterial sensors are indispensable in environmental monitoring, analysis of food and drink safety, prevention and treatment of pathogenic infections, antibiotic resistance screening, in combatting biocorrosion, and in biodefense. Recent discoveries within Human Microbiome project disclosed vital bacteria's role in human health and disease prognosis and treatment; they also placed in focus new analytical tools for bacterial analysis. Here, I discuss several basic concepts underlying the electrochemical bacterial biosensors: metabolic sensors, biosensors for DNA and RNA extracted from bacterial cells, and whole bacterial cell sensors, and their contribution to practically sought solutions for bacterial analysis. Current analytical issues and perspectives are outlined.  相似文献   

14.
分子印迹聚合物具有空间结构选择性高、稳定性好和制备过程简单等特点,结合表面等离子共振传感器,可用于分子间相互作用和结合特性的研究。随着石墨烯、量子点等纳米材料的出现和广泛应用,基于分子印迹技术的表面等离子共振传感器的灵敏度获得了改善,促进了该技术在食品安全检测领域的快速发展。该文基于分子印迹技术简要介绍了表面等离子共振传感器芯片的制备技术、分析体系及其优点,重点分析了国内外将分子印迹-表面等离子共振传感器用于食品安全检测的最新研究成果,阐释了分子印迹-表面等离子共振技术的优势,并展望了该技术在食品安全分析领域的发展趋势。  相似文献   

15.
The mass transfer in amperometric gas sensors intended for atmosphere monitoring is studied theoretically and experimentally. External and internal constituents of the diffusion resistance (DR) of the sensors are determined. The external constituent is defined by conditions of convective diffusion of air under analysis relative to the sensor. The internal constituents are defined by parameters of construction of sensor elements, and electrolyte film, as well as the structure of the indicator electrode, and solubility of the gas under analysis in the electrolyte. Testing a chlorine sensor shows that the DR of the internal constituents is independent of the conditions of convective diffusion of the environment under analysis near the sensor. The similarity criterion of sensors of different types is shown to be the relative share of DRs of individual constituents in the overall DR of the sensor. The results obtained can be used for the development and design of sensors with required range and resolution.  相似文献   

16.
光电化学传感器以光作为激发源,以光电流或光电压作为检测信号,具有响应快速、灵敏度高、设备简单等特点,目前已在环境、食品、医学等多个领域的分析测试中得到广泛应用。该文阐述了光电转换材料与光电化学传感器的制备方法,介绍了光电化学传感器的原理和分类。光电化学传感器包含光寻址电位型传感器和电流型光电化学传感器,其中,电流型光电化学传感器由于优良的光电性能、检出限低、所需材料低廉且易加工等优势而被广泛应用。文中着重介绍了电流型光电化学传感器在金属离子、有机污染物、核酸、蛋白质、细胞等方面的应用,并对光电化学传感器的发展前景进行了展望。  相似文献   

17.
We review the state-of-the-art application of nanoparticles (NPs) in electrochemical analysis of environmental pollutants. We summarize methods for preparing NPs and modifying electrode surfaces with NPs. We describe several examples of applications in environmental electrochemical sensors and performance in terms of sensitivity and selectivity for both metal and metal-oxide NPs. We present recent trends in the beneficial use of NPs in constructing electrochemical sensors for environmental monitoring and discuss future challenges.NPs have promising potential to increase competitiveness of electrochemical sensors in environmental monitoring, though research has focused mainly on development of methodology for fabricating new sensors, and the number of studies for optimizing the performance of sensors and the applicability to real samples is still limited.  相似文献   

18.
在现代分析领域中,对于生物传感器的要求不断倾向于微型化和便捷化。基于酶型生物燃料电池的自供能传感器在检测目标物的同时可以提供能量,避免了外电源的使用,为生物传感器的微型化和便捷化发展提供了有效途径,日益成为人们关注的焦点。本文按照设计原理进行分类,对近五年内发展的基于酶型生物燃料电池的自供能传感器进行了综述,并展望了其今后的研究趋势和应用前景。  相似文献   

19.
Electroanalytical sensors, suitable for the analysis and monitoring of electroactive analytes present in gaseous phase or low-conductive liquid media, and based on electrodes in close contact with perfluorinated ion-exchange polymers are reviewed. The basic operative mechanism of these sensors, in which ion-exchange polymers act as solid polymer electrolytes (SPE's), is thoroughly discussed, while stressing the fundamental reasons why their behavior differs from that of conventional membrane electrodes. The procedures for preparing composite working electrodes by coating one side of ion-exchange membranes with stable porous films of conductive materials are described, along with the most common strategies followed to assemble this type of sensors. Useful examples of measurements in electrolyte-free media of inorganic and organic electroactive species of interest mainly for environmental analysis are given. Future prospects for the development of these sensors are also discussed.  相似文献   

20.
The literature data published in 1993–2012 on the development and application of optical sensors for the determination of phenolic compounds of various structures are summarized. The design, analytical characteristics, and advantages and disadvantages of the existing optical sensors are reviewed, and some examples of using optical sensors in the analysis of real samples, including those from field experiments, are considered in detail.  相似文献   

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