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On-chip contactless four-electrode conductivity detection for capillary electrophoresis devices


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Laugere, F and Guijt, RM and Bastemeijer, J and van der Steen, G and Berthold, A and Baltussen, E and Sarro, PM and van Dedem, GWK and Vellekoop, MJ and Bossche, Aé (2003) On-chip contactless four-electrode conductivity detection for capillary electrophoresis devices. Analytical Chemistry, 75 (2). pp. 306-312. ISSN 0003-2700

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In this contribution, a capillary electrophoresis microdevice with an integrated on-chip contactless four-electrode conductivity detector is presented. A 6-cm-long, 70-μm-wide, and 20-μm-deep channel was etched in a glass substrate that was bonded to a second glass substrate in order to form a sealed channel. Four contactless electrodes (metal electrodes covered by 30-nm silicon carbide) were deposited and patterned on the second glass substrate for on-chip conductivity detection. Contactless conductivity detection was performed in either a two- or a four-electrode configuration. Experimental results confirmed the improved characteristics of the four-electrode configuration over the classical two-electrode detection setup. The four-electrode configuration allows for sensitive detection for varying carrier-electrolyte background conductivity without the need for adjustment of the measurement frequency. Reproducible electrophoretic separations of three inorganic cations (K+, Na+, Li+) and six organic acids are presented. Detection as low as 5 μM for potassium was demonstrated.

Item Type: Article
Journal or Publication Title: Analytical Chemistry
Page Range: pp. 306-312
ISSN: 0003-2700
Identification Number - DOI: 10.1021/ac0157371
Additional Information:

Copyright 2002 American Chemical Society.

Date Deposited: 22 Apr 2008 06:37
Last Modified: 18 Nov 2014 03:38
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