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The Effects of the Electrode System Geometry on the Properties of Contactless Conductivity Detectors for Capillary Electrophoresis
Author(s) -
Novotný Martin,
Opekar František,
Štulík Karel
Publication year - 2005
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200403232
Subject(s) - electrode , detector , planar , capillary action , thermal conductivity detector , materials science , conductivity , capillary electrophoresis , noise (video) , analytical chemistry (journal) , optics , chemistry , optoelectronics , chromatography , physics , composite material , computer graphics (images) , image (mathematics) , artificial intelligence , computer science
The basic analytical parameters of contactless conductivity detectors with planar, semi‐tubular and tubular electrodes have been compared. It has been found that the differences in the analytical parameters of the detectors are not significant for analytical use. The mean values of baseline peak‐to‐peak noise of 0.27, 0.35 and 0.33 mV, sensitivities of 0.97, 2.08 and 2.27 mV/pg (for K + ion), limits of detection of 0.93, 0.65 and 0.53, and the heights equivalent to a theoretical plate of 2.83, 2.39 and 2.40 μm were obtained for the detectors with planar, semi/tubular and tubular electrodes, respectively. Modifications of the basic detectors, namely a detector with thinned capillary wall and planar electrodes, and a detector with semi‐tubular electrodes placed one against the other on the opposite sides of the capillary were also tested. The configuration with the electrodes placed one against the other permits detector construction with zero gap between the electrodes without increasing the noise; when the electrodes overlap, the detector begins to operate as a permittivity detector.