流动注射分析血清中葡萄糖的电化学检测池

测定血清中葡萄糖含量是临床检验的重要项目之一。何立千曾对各种血糖测定方法做过综述。葡萄糖氧化酶-4-氨基安替比林-苯酚光度法(酶制剂法)虽能较好地测定血清中葡萄糖的含量,但成本较高,耗时长。因此有必要研究一种快速、廉价、稳定的分析方法。人们考虑到酶的专属性,对葡萄糖氧化酶电极做了大量工作,然而,这种电极的寿命仍不理想。     

A Simple Low-Cost Conductivity Cell for Flow Analysis Measurements

Abstract

A versatile low-cost conductivity flow-cell design is proposed. Its characteristics permit discrete variations in the cell volume and in the electrode area/distance ratio by varying the sealing gasket thickness, favoring high sensitivity applications in continuous flow measurements. Its dynamic characteristics as a flow conductivity detector were observed using a single-line FIA system and standard KC1 solutions, while its performance in routine work was tested by determining the NH₄ ⁺ content in plant Kjeldahl digests using FIA processing. These results are in good agreement with those obtained by the usual distillation/titration method.     

Application of a Hexa-Electrode Electrochemical Detector for Flow Injection Analysis

Extending from the development of dual-electrode electrochemical detector, a hexa-electrode electrochemical detector for use with the FIA was proposed. With this hexa-electrode detector, the in-series and in-parallel modes of dual-electrode can be easily performed either individually or simultaneously. Feasibility of the hexa-electrode detector for repetitive analyses which would result in an enhancement of S/N ratio was demonstrated by running the square wave anodic stripping voltammetry (SWASV) analysis of cadmium. From the normalized linear calibration graph and the enhanced sensitivity obtained. applicability of the HED as a versatile electrochemical detector for flow injection analysis was confirmed.     

Fabrication and Characterization of a Thin-Layer Electrochemical Flow Cell and Its Application for Flow Analysis

The design and fabrication of a home-made thin-layer electrochemical flow cell are reported. The performance and electrochemical characteristics of thin-layer cells are evaluated in terms of flow rate and channel thickness. The adaptability of the flow cell for amperometric and electrochemiluminescence measurements is demonstrated. Also, a flow injection method comprising electrochemical generation followed by spectrophotometric detection is proposed for determination of bromide using the fabricated cell. The influence of chemical, electrochemical, and flow parameters on the absorbance and current signals are investigated, and under optimized conditions, the analytical features of the proposed method with respect to bromide detection are evaluated.     

Direct Solid-Phase Optical Measurements in Flow Systems: A Review

Measurements based on absorption, reflectance, or luminescence of molecular species or complex ions can be carried out directly on a solid support simultaneously to the retention of the analyte. The use of this strategy in flow-based systems is advantageous in view of the reproducible handling of solutions in retention and elution steps of the analyte. This approach can be exploited to increase sensitivity, minimize reagent consumption as well as waste generation, improve selectivity or for simultaneous determination based on selective retention or differences in sorption rates of the analytes. This review focuses on the main characteristics of direct solid-phase measurements in flow systems, including the discussion of advantages and limitations and practical guidelines to the successful implementation of this approach. Selected applications in diverse fields, such as pharmaceutical, food, and environmental analysis are discussed.     

一种单细胞电化学模拟分析装置

单细胞分析是近年来生命科学中一个新兴热点研究领域。活细胞具有多种维持细胞生物活性的电化学活性物质 ,所以 ,建立在生物微环境中电极表面的电子传递反应的伏安测定对阐明细胞内发生的生化反应具有重要意义。我们设计制作了一种单细胞电化学模拟分析装置 ,让大体积的溶液生成一个微体积的小液滴 ,小液滴就是单细胞的模拟物 ,其大小与单细胞相仿。由于小液滴的成分与大体积溶液的成分相同 ,这样就可以人为地改变大体积溶液的成分与含量 ,来达到控制微体积小液滴的成分及含量的目的 ,给微电极的测定分析、选择和研究带来很大的方便 ,很容易对测定所用的微电极进行选择 ,找到该微电极对微滴中某成分的响应规律及相应的干扰组分 ,从而应用于单细胞内液中有关成分的实际测定。本装置结构简单 ,具有易建立、易操作的特点     

Flow Injection Analysis of Iodate Reduction on PEDOT Modified Electrode

Poly‐(3,4‐ethylenedioxythiophene) (PEDOT) films were electrodeposited by cyclic voltammetry on glassy carbon electrode at different anodic potentials in the range of 1.0–1.5 V (Ag/AgCl) and its electrocatalytic properties towards reduction of iodate were reported. The effect of the pH of the solution on the response of PEDOT electrode towards iodate also studied. The modified electrode was employed successfully as an amperometric sensor for iodate in a flow injection apparatus. The repeatability of the method for 14 injections of a μM iodate solution was 7%. Interference from other oxidant anions such as nitrate was not noticeable, whereas bromate, chlorate and nitrite interfere at slight levels.     

A Novel Flow Injection Optical Fiber Biosensor for Hypoxanthine Based on Luminol Electrochemiluminescence

IntroductionIn the food industry,the determination of hy-poxanthine in fish meatcan be regarded as a simplemethod for evaluating fish freshness.When a fishis caught and killed,the breakdown of adenosine-5 - triphosphate( ATP) in the fish meat results inthe release of adenosine- 5 - diphosphate ( ADP) ,and further degradation products are adenosine- 5 -monophosphate( AMP) ,inosine- 5 - monophosphate( IMP) ,inosine( Hx R) ,hypoxanthine( Hx) ,xan-thine( X) and uric acid( UA) . It has be…     

Tubular Detector of Silver Solid Amalgam for Electrochemical Measurements in Flow Systems

This paper presents the application of the tubular detector based on silver solid amalgam (TD‐AgSA) for electrochemical determinations of reducible inorganic (Cd²⁺, Zn²⁺) and organic (4‐nitrophenol) compounds under flow injection analysis conditions. The newly developed TD‐AgSA is simple, robust and inexpensive. The limits of detections of Zn²⁺, Cd²⁺ and 4‐nitrophenol are 1.4×10^?6, 7.0×10^?7, and 5.0×10^?7 mol dm^?3, respectively (i.e. 0.09, 0.08 and 0.07 ppm). The obtained results proved the long‐term stability of the detector (RSD of the determination of Zn²⁺, Cd²⁺, and 4‐nitrophenol were 0.8, 0.9 and 0.8 % (n=10; c_Zn=7.7×10^?5 mol dm^?3, c_Cd=4.5×10^?5 mol dm^?3 and c_4‐NPh=3.6×10^?5 mol dm^?3), respectively and its applicability for cathodic measurements in aqueous solutions at potentials up to ?2 V.     

自组装金电极的电化学测试及其FTIR和AFM分析

利用交流阻抗谱测试了自组装免疫电极的抗原响应特性，对生物电极解离过程的机理进行了研究，用傅里叶变换红外反射光谱（FTIR）和原子力显微镜（AFM）对电化学实验过程进行了直观观测和定量分析。     

测定青霉素浓度的流动注射分析系统及其特性的研究

基于青霉素在青霉素酶的作用下会水解生成青霉素酸，降低了系统的ｐＨ值，一个青霉素流动注射分析系统在我们实验室建立起来了。大量的实验结果表明，青霉素浓度与［Ｈ￣＋］输出峰面积成正比，与［Ｈ￣＿］输出峰高成非线性关系，青霉素浓度的峰面积计算法比峰高计算法具有更高的准确性。     

Measurements and Analysis of Electrochemical Noise of Li-Ion Battery

Russian Journal of Electrochemistry - Electrochemical noise of Li-ion rechargeable battery was measured during its discharging via a constant-value resistor. Statistical analysis of the measured...     

肾上腺素在亚甲绿碳糊修饰电极上的电催化氧化及流动注射分析

将亚甲绿浊混合在碳糊中制成化学修饰电极对肾上腺素的氧化具有良好的电催化作用，降低Ｅｐ氧化过电位４００ｍＶ。该电极用于流动注射分析能大大提高Ｅｐ的检测灵敏度。     

A Reference Electrode System for Electrochemical Measurements in Pure Water

A reference hydrogen electrode systems is constructed by employing a strip of proton‐type Nafion membrane as an ion‐conducting “bridge” to connect a reversible hydrogen electrode (RHE) in an acidic solution to an electrochemical system using pure water as electrolyte, in which the working electrode (WE) is placed. Using such a reference electrode system, the potential at the “WE/pure water” interface is equal to the equilibrium hydrogen electrode potential in pure water when the potential difference between RHE and WE is zero, irrespective of the pH value of the acidic solution in the RHE compartment. The accuracy and reproducibility of the WE potential measurements are within 1–2 mV.     

Silver Amalgam Tubular Detector Combined with Platinum Auxiliary Electrode for Electrochemical Measurements in Flow Systems

A new type of tubular detector with platinum auxiliary electrode inside the silver amalgam tube (TD+AuxE) was proposed, fabricated, tested and compared with a typical silver amalgam tubular detector developed earlier. Non‐stop‐flow differential pulse voltammetric anodic stripping method (AS‐DPV) and amperometric method in a glucose oxidase biosensor arrangement were tested. Both detectors were applied for AS‐DPV detection in flow systems for the first time. Solutions of zinc and cadmium cations were used as the testing species for voltammetry, and detection of oxygen concentration was used for amperometry. All these experiments require application of highly negative potentials, which is possible to realize with detectors made of silver solid amalgam. The proposed combination of TD+AuxE provides a much greater current response than the arrangement with three individual electrodes. All relevant parameters were optimized for the developed TD+AuxE. The simple and fast measuring protocol for the determination of the zinc content in commercial food supplement tablets has been developed.     

Chemiluminescent Method for Flow Injection Analysis of Anions

Abstract

We present here the preliminary results on a new flow injection chemiluminescent method of analysis for anions. This technique is rapid and sensitive with detection limits on the order of 1 × 10^?6M for chloride and 30 samples/hr possible.     

在线自发电源激发的流动注射电致化学发光测定异烟肼

采用了一种与流动注射体系组合的在线自发电池作为电致化学发光的激发源（ 简称FI－GCECL）。实验发现在碱性介质中，Al/Ag双金属对可以提供稳定的电位输 出并可激发鲁米诺在铂电极表面的电致化学发光。此自发电池具有使用寿命长、电 位可由碱性介质组成调节、可组合到流动注射体系中等特点，利用这种组合体系， 检测了三家厂生产的片剂中的异烟肼含量，将结果与药典标准方法进行了比较，证 明了这种电致发光分析的可行性。     

Electrocatalytic Reduction and Flow Injection Analysis of Organic Peroxides at Polymeric Tetra-Amino Iron Phthalocyanine Modified Electrode

Abstract

It has been demonstrated that tetra-amino iron phthalocyanine can be polymerized onto a glassy carbon electrode by electrooxidation of the monomer in solution. Organic peroxides can be catalytically reduced at such polymeric film modified electrode. While on a bare glassy carbon electrode, none of the peroxides can be reduced within the potential range studied. When used in flow injection analysis, the modified electrode permits the detection of these compounds by reduction mechanism at higher potentials without the interference from oxygen. The response is stable and has a wide dynamic range.