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A contactless conductivity detector for capillary electrophoresis: Effects of the detection cell geometry on the detector performance
Author(s) -
Tůma Petr,
Opekar František,
Štulík Karel
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200211)23:21<3718::aid-elps3718>3.0.co;2-u
Subject(s) - detector , electrode , thermal conductivity detector , materials science , conductivity , sensitivity (control systems) , noise (video) , optoelectronics , analytical chemistry (journal) , capillary action , capillary electrophoresis , optics , chemistry , physics , electronic engineering , chromatography , computer science , composite material , artificial intelligence , image (mathematics) , engineering
The effect of the gap between the electrodes and of their width on the behavior of a capacitively wired contactless conductivity detector was studied. The results obtained have indicated that the detector response can be qualitatively described by a model based on the concept of the effective electrode width which is a complex parameter determined by the gap between the electrodes, the frequency of the input signal and the conductivity of the test solution. The detector sensitivity and the effect on the separation efficiency depend on the difference between the effective and geometric electrode widths. Higher detection sensitivities have been attained for detectors with wide electrodes operating at lower frequencies, however, better separation efficiencies have been achieved using detectors with narrow electrodes and higher operational frequencies. The noise increases with decreasing gap between the electrodes and increasing frequency, especially with detectors employing narrow electrodes.