耦联式安培-电导检测器的研制及其在CE中的应用

毛细管电泳(CE)检测器的研究是一个具有挑战性的课题.目前已发展的一些检测方法有光学、电化学、质谱的和放射同位素等.     

毛细管电泳光学检测器的进展

对毛细管电泳的光学检测器作了简要评述。根据所采用的检测原理。光源检测器可分为紫外检测器，激光诱导荧光检测器、化学肆光检测器、荷耦合器件检测器、折射指数检测器等许多种类，具有简单方便、使用广泛，信息量较大等特点，是一类有良好诉检测器。     

发光二极管诱导荧光检测器*

发光二极管诱导荧光检测器（LED-IF）是近十年来发展起来的一种微型化荧光检测器,在流动注射、毛细管液相色谱、毛细管电泳及芯片电泳等微流动分析系统中具有广泛的应用。本文讨论了LED-IF的4种光学结构,并对其主要器件,包括光源、滤光片、透镜、光纤、光电检测器以及检测池作了详细讨论,还介绍了LED-IF与其它技术的联用及其在生物、医药和环境样品检测中的应用,对未来的发展趋势作了展望。     

毛细管电泳和火焰光度检测器的联用研究

研究了毛细管电泳与火焰光度检测器的联用技术及其应用。有机磷农药经毛细管电泳分离后，流出液被引入气相色谱的火娄光度检测器进行特效检测，毛细管电泳的接地电极接口采用毛细管裂缝处裹醋酸纤维膜的方法，而毛细管电泳和火焰光度检测器的接口则借用了气相色谱的进样口。     

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。     

高效毛细管电泳-电荷耦合器件检测器联用技术研究(Ⅶ)──低聚肽及其降解产物的分离

高效毛细管电泳－电荷耦合器件检测器联用技术研究（Ⅶ）──低聚肽及其降解产物的分离熊少祥,李建军,程介克（武汉大学化学系,武汉,４３００７２）关键词毛细管电泳．电荷耦合器件检测器．荧光检测．联用技术多肽及其降解产物氨基酸是组成生命物质蛋白质的基础,某些...     

毛细管电泳与化学发光检测联用方法的研究进展

毛细管电泳由于其超高的分离效率广泛应用于生物医药、环境监测、食品科学以及公共安全等领域。然而,由于毛细管电泳具有进样量较少、检测光程较短等缺点,需要与高灵敏度检测器联用实现低浓度样品的分析。化学发光检测由于其背景信号低而具有超高的灵敏度。毛细管电泳-化学发光检测联用方法将毛细管电泳的高效分离特性与化学发光检测的高灵敏性相结合,成为一种非常重要的分析方法,广泛用于化学分析、药物筛选以及环境监测等领域。该文对近年来毛细管电泳-化学发光检测联用方法的基本原理进行概述,并对其发展趋势和应用前景进行了展望。     

发光二极管诱导荧光用于毛细管电泳检测

利用发光二极管作为激发光源，组装了用于毛细管电泳的荧光检测器。光纤用于传输荧光信号；光纤端面修饰成球形使耦合效率比平面端光纤提高了50．8％；光阑、光纤及毛细管检测池之间的光学校准简单、便捷。荧光素染料用于评价该体系性能，得到了fmol的质量检出限。     

毛细管电泳化学发光在线检测

评论了毛细管区带电泳化学发光检测联用技术这一新兴的研究领域。化学发光检测具有背景低、热力学范围宽、灵敏度高的优点，适于毛细管电泳柱后微量样品的在线检测。论述了该检测器与毛细管电泳联用的接口和应用状况。     

毛细管区带电泳电化学检测器

本文阐述了毛细管区带电泳探针式安培检测器的构造、工作原理、理论及其与电泳系统的联结技术;介绍了该检测器的应用情况。     

The application of spline wavelet transform to the determination of electroosmotic mobility in capillary electrophoresis

The rule of current change was studied during capillary electrophoresis (CE) separation process while the conductivity of the sample solution was different from that of the buffer. Using a quadratic spline wavelet of compact support, the wavelet transforms (WTs) of capillary electrophoretic currents were performed. The time corresponding to the maximum of WT coefficients was chosen as the time of current inflection to calculate electroosmotic mobility. The proposed method was suitable for different CE modes, including capillary zone electrophoresis, nonaqueous CE and micellar electrokinetic chromatography. Compared with the neutral marker method, the relative errors of the developed method for the determination of electroosmotic mobility were all below 2.5%.     

A new capillary electrophoresis end-column amperometric detection system without the need for capillary/electrode alignment

A self-aligning end-column amperometric detection system for capillary electrophoresis was constructed. In this system, the electrode and capillary were exchanged easily and the capillary/electrode alignment procedure is not required. Gold, gold/mercury amalgam, copper and carbon fiber could be used as the working electrode. The principle is in the use of two disk holders with the capillary and the electrode in the center, so that by inserting the disk holders into a groove in the working electrode port, the capillary and the electrode are automatically aligned and the distance between the capillary and the electrode is assured at 0.24 mm. The relative standard deviation obtained using five different gold/mercury amalgam microdisk electrodes for determination of cysteine was 1.5% for the migration time and 3.3% for the electrophoretic peak current. The simple and convenient system was attractive for the routine analysis by capillary electrophoresis with electrochemical detection. The system was applied to the determination of promethazine hydrochloride in human serum.     

聚乙烯吡烙烷酮修饰碳糊电极-双通道毛细管电泳安培法测定环境中的硝基酚

建立了几种硝基酚的聚乙烯吡烙烷酮修饰碳糊电极-双通道毛细管电泳安培检测的新方法.采用双工作电极和两台伏安仪,将样品的检测电位分别设定在氧化电位(+0.5V_vs.SCE)和还原电位(-1.4V_vs.SCE),在一个检测池中同时获得所有样品的氧化和还原信息,以还原电流和氧化电流值之比(Nc=ir/io)作为定性依据,对样品的纯度进行确证.通过优化工作电极、检测电位、缓冲溶液、β-CD和乙醇浓度等实验参数,实现了几种硝基酚的分离检测,同时采用样条小波最小二乘法对样品数据信号进行处理,并将此法应用于实际样品的测定.     

Electrochemiluminescence detection system for microchip capillary electrophoresis and its application to pharmaceutical analysis

We describe an efficient and easily fabricated electrochemiluminescence detection system for microchip capillary electrophoresis. A 300-μm-diameter platinum disc working electrode was embedded in a titanium tube which provides an adequate holding for working electrode and acts as counter electrode. We also have designed a simplified detection cell with a guide channel for the electrode. The integrated working-counter electrode can be easily aligned to the outlet of the separation channel through the guide channel. The functionality of the system was demonstrated by separation and detection of proline and tripropylamine. The response to proline is linear in the range from 5 μM to 5,000 μM, and the detection limit is 1.0 μM (S/N?=?3). The system was further applied to the determination of chlorpromazine hydrochloride in pharmaceutical formulations. The system is believed to have potential applications in pharmaceutical analysis.

Incorporation of Disposable Screen‐Printed Electrodes for Use in Capillary Electrophoresis End‐Column Amperometric Detection System

The development and performance of an end‐column amperometric detection system integrated with disposable screen‐printed electrodes for capillary electrophoresis is presented. In this system, the electrode and capillary can be easily replaced and the capillary/electrode alignment procedure is straightforward. The use of easily replaceable screen‐printed electrodes offers a tremendous benefit for capillary electrophoresis applications requiring frequent replacement of the working electrode due to fouling. This simple and convenient system is very attractive for routine analyses by capillary electrophoresis with electrochemical detection. The separation and determination of uric acid in human urine is presented.     

Analysis of alkyl polyglucosides in industrial products by capillary electrophoresis with pulsed amperometric detection

Pulsed amperometric detection following micellar electrokinetic chromatography has been applied successfully to the direct detection of alkyl polyglucosides (APGs) in shampoos and other industrial products without prior conversion to highly absorbing or fluorescing derivatives. For electrochemical detection, it is necessary to dissociate the hydroxyl groups of the APGs. Thus, we used 0.1 M NaOH in the outlet vial to dissociate the APGs. The main problems associated with the combination of electrochemical detection and capillary electrophoresis are the need to isolate the detector from the electric field used in the capillary electrophoresis separation and the difficulty of aligning the working electrode with the end of the capillary. To overcome these problems, a simple capillary-electrode holder was constructed. This holder automatically aligns the capillary and the electrode in a wall-jet configuration without the aid of micropositioners and facilitates the replacement of electrodes and capillaries without reconstruction of the entire capillary/electrode setup. Special microcylindrical gold electrodes have been produced by sealing 300-μm-diameter gold wire into borosilicate-glass capillaries.     

Sheath-flow electrochemical detection of amino acids with a copper wire electrode in capillary electrophoresis

Here, we report the detection of native amino acids using a sheath-flow electrochemical detector with a working electrode made of copper wire. A separation capillary that was inserted into a platinum tube in the detector acted as a grounded electrode for electrophoresis and as a flow channel for sheath liquid. Sheath liquid flowed outside the capillary to support the transport of the separated analytes to the working electrode for electrochemical detection. The copper wire electrode was aligned at the outlet of the capillary in a wall-jet configuration. Amino acids injected into the capillary were separated following elution from the end of the capillary and detection by the copper electrode. Three kinds of copper electrodes with different diameters-50, 125, and 300 μm-were examined to investigate the effect of the electrode diameter on sensitivity. The peak widths of the analytes were independent of the diameter of the working electrode, while the 300-μm electrode led to a decrease in the signal-to-noise ratio compared with the 50- and 125-μm electrodes, which showed no significant difference. The flow rate of the sheath liquid was also varied to optimize the detection conditions. The limits of detection for amino acids ranged from 4.4 to 27 μM under optimal conditions.     

A new electrode chamber for stable performance in capillary electrophoresis

Prerequisite to running automated sequences of analyses in capillary electrophoresis is a stable performance of the system. The products of the electrode reaction with the running background electrolyte (BGE) may play an important role, since even the neutral products may be driven into the capillary by electroosmosis and may severely deteriorate the stability of the baseline. Here, a simple, inexpensive, and fast procedure is described for improving the stability of the performance of capillary electrophoresis using a modified vial serving as the electrode chamber for the running BGE. The modification is based on creating two separate rooms in the vial, one for the electrode and a second one for the capillary. These two rooms are connected by a cotton plug. When both rooms are filled with the running BGE, the electrolytic connection between the electrode and the capillary is ensured; however, the convective transport of the electrode reaction products into the capillary is practically eliminated.     

Integration of Separation Capillary with a Au Film Electrode and an Etched Decoupler in Amperometric Capillary Electrophoresis

Introduced in this article is fabrication of an integrated capillary for the applications of electrochemical detection in capillary electrophoresis. The separation section, voltage decoupler, and working electrode were composed into a single section of capillary. The porous decoupler was constructed by HF etching till the thickness of the capillary wall less than 20 μm. The working electrode was prepared by sputtering Au-films on the outlet of the capillary. The integration of the separation capillary with a complete detection assembly improves the convenience for the routine application of electrochemical measurements in capillary electrophoresis. For a 100-μm-i.d. capillary, the theoretical plate number of catechol and the migration time reproducibility can reach 120,000 and 1.9% RSD, respectively. The linear range exceeds 3 order of magnitude and the detection limit is lower than 0.65 μM.     

A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products.