一种基于双工作电极-双通道的毛细管电泳电化学检测系统

报道了一种双工作电极-双通道毛细管电泳电化学检测系统，实现电导和安培 同时检测或者安培与安培检测联用，使两种方法相互补充，发挥各自的优势。其中 ，工作电极与检测池的制作工艺简单，操作简便，通过不锈钢针管和毛细管作为套 管，无需三维微调装置即可简单实现双工作电极的准确放置及分离毛细管与工作电 极的准确对接，并根据分析体系的需要采用不同类型的工作电极和检测器；同时采 用复式滤波电路解决了不同检测器之间的电场叠加对输出信号的干扰问题。采用该 装置可以同时检测复杂体系中的电活性和惰性物质，或同时测定只能氧化或只能还 原的物质，还可以对具有氧化还原性质的物质进行纯度的确证。将该装置应用于实 际样品的测定，节约了分析时间，提高了分析速度，扩大了检测范围，结果令人满 意。     

毛细管电泳多道电化学检测器的研制及其应用

报道了毛细管电泳多道电化学检测器的研制及其应用，安培检测器和电导检测器并联在同一毛细管电泳检测系统中，在同一缓冲体系，同一工作电极下对同一复杂的分析体系同时进行电导和安培检测；整个装置综合了电导检测和安培检测两种检测器的优点，性能优良，造价低廉，对实际样品的检测取得了令人满意的结果。     

Conductivity detection in capillary electrophoresis

Among electrochemical detection methods in capillary electrophoresis, conductometric methods are of specific interest for the determination of inorganic species. This is due to the fact that inorganic ions exhibit a high equivalent conductivity which corresponds to the analytical signal in conductivity detection. Indirect optical absorption methods, which are widely used in capillary electrophoretic ion analyses, become less sensitive with smaller capillary dimensions and thus have disadvantages in electrokinetic chip separation technologies.Conductivity detection for capillary electrophoresis is performed either through galvanic contact or in a contactless mode. Techniques using a galvanic contact of the sample ions with the measuring electrode are performed either on-capillary without decoupling of the separation high voltage, or off-capillary after grounding the separation voltage in order to avoid interferences. This technology is specifically important when a suppressor is used prior to detection. Most contactless methods use oscillometric techniques in order to obtain the analytical signal.This review discusses the theoretical and instrumental background of conductivity detection in capillary electrophoresis and reports on recent aspects and applications using conductometric detection methods for capillary zone electrophoresis.     

毛细管电泳-荧光/非接触电导组合型检测器的研制

报道了一种毛细管电泳-荧光／非接触电导组合型检测器。该检测器共用非接触电导检测池,实现了双检测器响应同步。优化了非接触电导检测系统中激发电压信号及其频率;荧光检测是用发光二极管作为激发光源,用光纤收集并传输荧光信号至光电倍增管。用无机金属离子和异硫氰酸荧光素评价该体系,结果表明,该检测器达到了任一单类型检测器性能指标。     

毛细管电泳安培及电导检测最新进展

对毛细管电泳安培检测和电导检测的研究近况进行了综述,分别介绍了电导法和安培法与毛细管电泳的联接及应用,并对其发展方向作了展望。     

Nickel Amperometric Detector Prepared by Electroless Deposition for Microchip Electrophoretic Measurement of Alcohols and Sugars

Nickel was deposited directly at the end of an electrophoretic glass microchip using an electroless deposition procedure leading to an attractive amperometric detector for sugars and alcohols. Such direct electroless deposition of nickel at the end of the separation chip greatly simplifies the preparation of on‐chip electrochemical detectors. Variables affecting the preparation and operation of the new detector are characterized and optimized. The integrated capillary electrophoresis‐electrochemical detection microsystem was evaluated for the separation of alcohols and sugars in connection to assays of different beer and wine samples. Linear calibration plots and favorable detection limits are found that meet the needs of real sample (wine and beer) analyses. This represents the first example of using nickel electrode and detecting alcohols on microchip platforms.     

Electrochemical Detection of Capillary Electrophoresis and Its Data Processing using Spline Wavelet Least Square

In this paper, two new electrochemical detection for capillary electrophoresis and its data processing by spline wavelet least square have been presented. An new type of on-column conductometric detection was assembled. A photo-couple separator was adopted in order to eliminate the influence of high voltage.     

Advances in amperometric and conductometric detection in capillary and chip-based electrophoresis

Amperometric and conductometric detection are currently the two major electrochemical detection modes in capillary and chip electrophoresis. The ease of miniaturization and integration of electrochemical detection elements offers a high potential for the development of portable analytical devices based on electromigrative separations. The challenges and basic concepts of both detection principles in the context of capillary/chip electrophoresis are shortly introduced and milestones of the methodical developments are summarized from a historical perspective. Recent advances and applications are discussed with more detail. Particular attention is paid to new trends in this area of research such as measurements in short capillaries and the enormous progress and increased popularity of contactless conductivity detection. Correspondence: Frank-Michael Matysik, Institute of Analytical Chemistry, University of Leipzig, Linnéstr. 3, D-04103 Leipzig, Germany     

Improved dual photometric-contactless conductometric detector for capillary electrophoresis

A new design of a dual, UV photometric - contactless conductometric detector is described. The separation capillary with an optical window created is pressed onto two semitubular electrodes, 3 mm wide and 2 mm apart. The electrodes form the detection cell of the contactless conductometric detector. An optical fiber, placed in the gap between the conductometric electrodes, brings radiation from the source. The radiation that passes through the separation capillary is recorded by a large-area photodiode. The optical fiber and the photodiode operate the photometric cell which is between the conductometric electrodes. The detector thus permits simultaneous photometric and conductometric detection in the same place of the capillary, while exchanging of the separation capillary is easy and without effect on the detector geometry and performance.     

Simultaneous light emitting diode-induced fluorescence and contactless conductivity detection for capillary electrophoresis.

A combined detection system of simultaneous contactless conductometric and fluorescent detection for capillary electrophoresis (CE) has been designed and evaluated. The two processes share a common detection cell. A blue light-emitting diode (LED) was used as the excitation source and an optical fiber was used to collect the emitting fluorescence for fluorescent detection (FD). Inorganic ions, fluorescein isothiocyanate (FITC)-labeled amino acids and small molecule peptides were separated and detected by the combined detector, and the detection limits (LODs) of sub-microM level were achieved.     

Electrochemical and optical detectors for capillary and chip separations

In separations in capillaries or on chips, the most predominant detectors outside of the field of proteomics are electrochemical (EC) and optical. These detectors operate in the μM to pM range on nL peak volumes with ms time resolution. The driving forces for improvement are different for the two classes of detectors.With EC detectors, there are two limitations that the field is trying to overcome. One is the ever-present surface of the electrode which, while often advantageous for its catalytic or adsorptive properties, is also frequently responsible for changes in sensitivity over time. The other is the decoupling of the electrical systems that operate electrokinetic separations from the system operating the detector.With optical detectors, there are similarly a small number of important limitations. One is the need to bring the portability (size, weight and power requirements) of the detection system into the range of EC detectors. The other is broadening and simplifying the applications of fluorescence detection, as it almost always involves derivatization.Limitations aside, the ability to make detector electrodes and focused laser beams of the order of 1 μm in size, and the rapid time response of both detectors has vaulted capillary and chip separations to the forefront of small sample, fast, low mass-detection limit analysis.     

Recent developments in electrochemical flow detections—A review: Part I. Flow analysis and capillary electrophoresis

Recent years have provided numerous new examples of applying flow-through electrochemical detectors in chemical analysis. This review, based on about 250 original research papers cited from the current analytical literature, presents their application in flow analysis and capillary electrophoretic methods. Example applications are also given for arrays of electrochemical sensors in flow analysis and electrochemical detection in microfluidic systems. Potentiometric detection with ion-selective electrodes predominates in flow analysis carried out mostly in a flow-injection system, while amperometric and conductivity detections are most commonly employed in capillary electrophoresis.     

毛细管电泳与芯片毛细管电泳的双检测技术

综述了毛细管电泳和芯片毛细管电泳的3种双检测技术,包括荧光-散射等光学双检测技术、安培-非接触电导等电化学双检测技术和荧光-非接触电导等光电联用双检测技术.介绍了3种双检测方法的仪器的检测原理及应用,并展望了双检测技术的发展前景.引用文献54篇.     

Development and Characterization of a Disposable Electrochemical Detector Arrangement for Capillary Electrophoresis Prepared by Thermal Lamination

A disposable electrochemical detector arrangement for capillary electrophoresis has been developed. The detection system consists of an assembly of a fused silica capillary and a microfiber electrode which are fixed in a proper position by sealing this configuration with the help of thermal lamination. The detector design is easy to prepare and inexpensive. Therefore it is used as a disposable device which can be replaced by a new one if any degradation of the performance characteristics occurs. The parameters influencing the detection performance were studied and optimized using nonaqueous capillary electrophoresis and ferrocene derivatives as model compounds. The practical utility was demonstrated by studying the separation and detection of water‐resistant dye compounds.     

Carbon nanotube and diamond as electrochemical detectors in microchip and conventional capillary electrophoresis

As two important polymorphs of carbon, carbon nanotube (CNT) and diamond have been widely employed as electrode materials for electrochemical sensing. This review focuses on recent advances and the key strategies in the fabrication and application of electrochemical detectors in microchip and conventional capillary electrophoresis (CE) using CNT and boron-doped diamond. The subjects covered include CNT-based electrochemical detectors in microchip CE, CNT-based electrochemical detectors in conventional CE, boron-doped diamond electrochemical detectors in microchip CE, and boron-doped diamond electrochemical detectors in conventional CE. The attractive properties of CNT and boron-doped diamond make them very promising materials for the electrochemical detection in microchip and conventional CE systems and other microfluidic analysis systems.     

用于高效毛细管电泳的电化学检测器

阐述了高效毛细管电泳电化学检测器（包括电导、电势和安培检测）的研究现状，重点是检测器的研制及接口的制作技术。对各种电化学检测器的应用情况也进行了总结。展望了高效毛细管电泳电化学检测的发展前景。     

Microchip electrophoresis with wall-jet electrochemical detector: influence of detection potential upon resolution of solutes

This report studies the electrochemical response of wall-jet detector for microchip electrophoresis (microCE). It shows that in wall-jet configuration, the electrochemical detector operates in coulometric mode and that there is an influence of detection potential upon peak width and therefore upon the resolution of solutes. Upon raising the detection potential from +0.3 to +0.9 V, the resolution between model analytes, dopamine and catechol, increases from 0.63 to 2.90. The reasons for this behavior originate in wall-jet detector design and in its typically significant higher detector volume than the volume of injected sample. The conversion efficiency of the wall-jet electrochemical detection cell was found to be 97.4% for dopamine and 98.0% for catechol. The paper brings deeper understanding of operations of wall-jet electrochemical detectors for microchip devices, and it explains previously reported significantly sharper peaks when electrocatalytic electrodes (i.e., palladium and carbon nanotube) were used in microCE-electrochemistry wall-jet detector.     

毛细管电泳电导法快速检测饲料添加剂氯化胆碱

采用毛细管电泳电导法对饲料添加剂氯化胆碱进行了测定.实验优化了缓冲介质、分离电压、毛细管长度和内径等参数.结果表明:在优化条件下,氯化胆碱在4 min左右可以实现分离检测,线性范围在41.8～1.20 μg/mL,检出限为0.8 μg/mL;迁移时间和峰面积的相对标准偏差分别为0.6%、2.1%;样品加标回收率为97%～105%.将该法用于粉剂和饲料中氯化胆碱的检测,取得了满意的结果.     

毛细管电泳多道电化学检测工作站

设计的毛细管电泳多通道电化学检测系统是一个可供在同一个检测环境下，用多台电化学检测器循环对物质进行测定的工作站。工作站采用计算机控制，利用电导和伏安检测器对样品同时进行电导、氧化和还原检测，并实时对数据进行采集，处理，以图形方式显示。     

Towards disposable lab-on-a-chip: poly(methylmethacrylate) microchip electrophoresis device with electrochemical detection

A fully disposable microanalytical device based on combination of poly(methylmethacrylate) (PMMA) capillary electrophoresis microchips and thick-film electrochemical detector strips is described. Variables influencing the separation efficiency and amperometric response, including separation voltage or detection potential are assessed and optimized. The versatility, simplicity and low-cost advantages of the new design are coupled to an attractive analytical performance, with good precision (relative standard deviation RSD = 1.68% for n = 10). Applicability for assays of mixtures of hydrazine, phenolic compounds, and catecholamines is demonstrated. Such coupling of low-cost PMMA-based microchips with thick-film electrochemical detectors holds great promise for mass production of single-use micrototal analytical systems.