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A parallel dual‐electrode detector for capillary electrophoresis
Author(s) -
Dorris Megan K.,
Crick Eric W.,
Lunte Craig E.
Publication year - 2012
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/elps.201200113
Subject(s) - electrode , capillary electrophoresis , working electrode , oxidizing agent , reference electrode , quinhydrone electrode , palladium hydrogen electrode , analytical chemistry (journal) , electrochemistry , electrode potential , redox , materials science , standard hydrogen electrode , chemistry , electrophoresis , detection limit , dual mode , capillary action , chromatography , inorganic chemistry , composite material , organic chemistry , engineering , aerospace engineering
An approach to on‐capillary dual‐electrode detection for CE using a parallel electrode configuration has been developed. The parallel configuration provides two operating modes. In the first mode, one working electrode is held at an oxidizing potential and the second working electrode is held at a reducing potential. This results in redox cycling of analytes between the oxidized and reduced forms, enhancing sensitivity compared to single‐electrode detection. In the second mode, both working electrodes are held at different oxidizing potentials. This mode provides electrochemical characterization of electrophoretic peaks. In the redox cyclying mode, signal enhancement of up to twofold was observed for the dual‐electrode detection of phenolic acid standards compared to single‐electrode detection. Variation in response of less than 10% from electrode to electrode was determined (at a concentration of 60 nM) indicating reproducible fabrication. LODs were determined to be as low as 5.0 nM for dual‐electrode configuration. Using the dual‐potential mode peak identification of targeted phenolic acids in whiskey samples were confirmed based on both migration time and current ratios.