Journal ArticleDOI
Fundamental aspects of contactless conductivity detection for capillary electrophoresis. Part II: Signal-to-noise ratio and stray capacitance.
Pavel Kubáň,Peter C. Hauser +1 more
TLDR
The signal‐to‐noise ratio of a contactless conductivity detector for capillary electrophoresis was examined for different cell arrangements and operating parameters and it was shown that the best signal-to-noise ratios were achieved for the highest excitation voltage of 200 Vpp.Abstract:
The signal-to-noise ratio of a contactless conductivity detector for capillary electrophoresis was examined for different cell arrangements and operating parameters. The best signal-to-noise ratios, and hence the best detection limits, are obtained for frequencies which give highest sensitivity. Comparative experiments for three different excitation voltages (20, 100, and 200 V p p ) showed that the best signal-to-noise ratios were achieved for the highest excitation voltage of 200 V p p . Low conductivity of the background electrolyte solution is mandatory to obtain lowest noise levels, and also the improvement on applying high excitation voltages was best for the electrolyte solution with lowest conductivity. The diameter of the electrodes was found to have only a negligible effect, so that a tight fitting of the electrodes to the external diameter of the capillary is not necessary. A cell without shielding between the two electrodes showed significant direct coupling (stray capacitance) and lower signal-to-noise ratios for all experimental conditions used. A serious distortion of the peak shapes was also observed for this cell arrangement.read more
Citations
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Journal ArticleDOI
A review of the recent achievements in capacitively coupled contactless conductivity detection
Pavel Kuban,Peter C. Hauser +1 more
TL;DR: Theoretical aspects of C(4)D in both the capillary and microchip electrophoresis format have been comprehensively investigated and the method can be considered a mature detection technique.
Journal ArticleDOI
Ten years of axial capacitively coupled contactless conductivity detection for CZE--a review.
Pavel Kubáň,Peter C. Hauser +1 more
TL;DR: It is attempted in this review to summarize some of the expertise accumulated since the introduction of the axial contactless conductivity detector to CE 10 years ago.
Journal ArticleDOI
Capacitively coupled contactless conductivity detection on microfluidic systems—ten years of development
Wendell K. T. Coltro,Renato S. Lima,Thiago Pinotti Segato,Emanuel Carrilho,Dosil Pereira de Jesus,Claudimir Lucio do Lago,José Alberto Fracassi da Silva +6 more
TL;DR: The use of capacitively coupled contactless conductivity detection (C4D) on miniaturized systems has increased considerably over the last few years as discussed by the authors, and several advances on the detection cell geometry, strategies for increasing the sensitivity and a wide range of applications have been reported.
Journal ArticleDOI
Recent applications of conductivity detection in capillary and chip electrophoresis.
Veronika Šolínová,Václav Kašička +1 more
TL;DR: The review provides a comprehensive survey of the recent applications of contact and contactless conductivity detection in capillary electrophoretic and chip electrophoreic analyses of a broad scale of compounds, from low-molecular-mass highly mobile small inorganic and organic ions up to high-molesculated biopolymers, proteins and nucleic acids fragments.
Journal ArticleDOI
Capacitively coupled contactless conductivity detection for microseparation techniques - recent developments.
Pavel Kubáň,Peter C. Hauser +1 more
TL;DR: An overview of the developments of capacitively coupled contactless conductivity detection in CE and related techniques over approximately the last 2 years is given and interesting new approaches on creating low cost devices have also appeared.
References
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Journal ArticleDOI
Contactless conductivity detection for capillary electrophoresis.
TL;DR: A contactless capacitively coupled conductivity detector for capillary electrophoresis is introduced and the limit of detection of inorganic cations and anions is 200 ppb, as determined for sodium and chloride, respectively.
Journal ArticleDOI
An Oscillometric Detector for Capillary Electrophoresis
TL;DR: An oscillometric detector for capillary electrophoresis has been described in this article, where two 2-mm silver rings separated by 1 mm were painted over the polyimide coating of a fused-silica capillary and used as electrodes for oscillometric measurements.
Journal ArticleDOI
Contactless Conductivity Detector for Microchip Capillary Electrophoresis
Martin Pumera,Joseph Wang,František Opekar,Ivan Jelínek,Jason Feldman,Holger Löwe,Steffen Hardt +6 more
TL;DR: The advantages associated with the contactless conductivity detection, along with the low cost of the integrated PMMA chip/detection system, should enhance the power and scope of microfluidic analytical devices.
Journal ArticleDOI
Fundamental aspects of contactless conductivity detection for capillary electrophoresis. Part I: Frequency behavior and cell geometry
Pavel Kubáň,Peter C. Hauser +1 more
TL;DR: A good fit between theoretical and experimental results shows that the axial contactless conductometric detector can effectively be described by the simplest possible equivalent circuitry consisting of a capacitor, resistor, and a second capacitor.
Journal ArticleDOI
High-frequency contactless conductivity detection in isotachophoresis
TL;DR: In this paper, a new detection system for isotachophoresis, the high-frequency contactless conductivity detector, is described, which has a high resolving power and gives good reproducibility.
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Fundamental aspects of contactless conductivity detection for capillary electrophoresis. Part I: Frequency behavior and cell geometry
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