Suppressed conductometric capillary electrophoresis separation systems

Dasgupta, Purnendu Κ.; Bao, Liyuan.

doi:10.1021/ac00056a010

Cited by 107 publications

(42 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In ion chromatography, very low detection limit at ppb (ng/mL) level can be reached by background depression. Introduction of background depression normally used in ion chromatography was also found effective in CE as demonstrated in the reports [27,28].…”

Section: Capillary Chip Electrophoresis With Conductivity Detectionmentioning

confidence: 97%

On‐column conductivity detection in capillary‐chip electrophoresis

Fang

Josserand

2007

Electrophoresis

View full text Add to dashboard Cite

On-column conductivity detection in capillary-chip electrophoresis was achieved by actively coupling the high electric field with two sensing electrodes connected to the main capillary channel through two side detection channels. The principle of this concept was demonstrated by using a glass chip with a separation channel incorporating two double-Ts. One double-T was used for sample introduction, and the other for detection. The two electrophoresis electrodes apply the high voltage and provide the current, and the two sensing electrodes connected to the separation channel through the second double-T and probe a potential difference. This potential difference is directly related to the local resistance or the conductivity of the solution defined by the two side channels on the main separation channel. A detection limit of 15 mM (600 ppb or 900 fg) was achieved for potassium ion in a 2 mM Tris-HCl buffer (pH 8.7) with a linear range of 2 orders of magnitude without any stacking. The proposed detection method avoids integrating the sensing electrodes directly within the separation channel and prevents any direct contact of the electrodes with the sample. The baseline signal can also be used for online monitoring of the electric field strength and electroosmosis mobility characterization in the separation channel.

show abstract

Section: Capillary Chip Electrophoresis With Conductivity Detectionmentioning

confidence: 97%

On‐column conductivity detection in capillary‐chip electrophoresis

Fang

Josserand

2007

Electrophoresis

View full text Add to dashboard Cite

show abstract

“…In 1993, two different research groups reported the use of a suppressor in combination with contact conductivity detection in CE [20,22]. Dasgupta and Bao [22] coupled a Nafion membrane between two pieces of fused-silica capillary.…”

Section: Contact Conductivity Detection In Capillariesmentioning

confidence: 99%

Conductivity detection for conventional and miniaturised capillary electrophoresis systems

Guijt¹,

Evenhuis²,

Macka³

et al. 2004

Electrophoresis

128

View full text Add to dashboard Cite

Since the introduction of capillary electrophoresis (CE), conductivity detection has been an attractive means of detection. No additional chemical properties are required for detection, and no loss in sensitivity is expected when miniaturising the detector to scale with narrow-bore capillaries or even to the microchip format. Integration of conductivity and CE, however, involves a challenging combination of engineering issues. In conductivity detection the resistance of the solution is most frequently measured in an alternating current (AC) circuit. The influence of capacitors both in series and in parallel with the solution resistance should be minimised during conductivity measurements. For contact conductivity measurements, the positioning and alignment of the detection electrodes is crucial. A contact conductivity detector for CE has been commercially available, but was withdrawn from the market. Microfabrication technology enables integration and precise alignment of electrodes, resulting in the popularity of conductivity detection in microfluidic devices. In contactless conductivity detection, the alignment of the electrodes with respect to the capillary is less crucial. Contactless conductivity detection (CCD) was introduced in capillary CE, and similar electronics have been applied for CCD using planar electrodes in microfluidic devices. A contactless conductivity detector for capillaries has been commercialised recently. In this review, different approaches towards conductivity detection in capillaries and chip-based CE are discussed. In contrast to previous reviews, the focus of the present review is on the technological developments and challenges in conductivity detection in CE.

show abstract

“…Similarly to ion-chromatography single-column and the suppressed one, introduction of suppressed conductivity detection to CE allows fot the decrease of the limit of detection for common organic and inorganic ions to the level 1 ± 10 ppb [180,181]. As is shown in Figure 9, the suppressor is made from a short ion-exchange membrane capillary and placed between the separation capillary and the ion-chromatography conductivity detector, with one of the conductivity electrodes being grounded.…”

Section: Conductivity Detection In Cementioning

confidence: 99%

Electroanalytical Flow Measurements–Recent Advances

2003

View full text Add to dashboard Cite

As general trends in current development of chemical analysis, including electroanalysis, one can indicate a search for methods fast and multianalyte, for miniaturized measuring devices, mechanization and automation of analytical processes. In all these trends a significant role is played by measurements in flow conditions. The major advantage of flow electroanalysis is a possibility of utilizing a kinetic discrimination in potentiometric measurements and enhancement of mass transport in voltammetric techniques. Flow injection techniques provide shortening of time of a single analytical determination due to reproducible use of transient signal from the detector without need of obtaining a steady-state equilibrium signal. Electrochemical detection in HPLC gives often improved selectivity and detection limit for electroactive solutes, whereas in capillary electrophoresis it allows a convenient design of portable, integrated chips for field application. This review presents state-of-the -art of flow electroanalysis based on 226 cited literature references

show abstract

Suppressed conductometric capillary electrophoresis separation systems

Cited by 107 publications

References 23 publications

On‐column conductivity detection in capillary‐chip electrophoresis

On‐column conductivity detection in capillary‐chip electrophoresis

Conductivity detection for conventional and miniaturised capillary electrophoresis systems

Electroanalytical Flow Measurements–Recent Advances

Contact Info

Product

Resources

About