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Disposable twin gold electrodes for amperometric detection in capillary electrophoresis
Author(s) -
Richter Eduardo M.,
Fracassi da Silva José A.,
Gutz Ivano G. Rolf,
do Lago Claudimir L.,
Angnes Lúcio
Publication year - 2004
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.200305960
Subject(s) - amperometry , microelectrode , potentiostat , electrode , capillary electrophoresis , ascorbic acid , capillary action , analytical chemistry (journal) , materials science , analyte , detection limit , working electrode , chromatography , frit , iodate , chemistry , iodide , electrochemistry , composite material , food science , organic chemistry
We describe a simple and easy way to construct gold microelectrodes for amperometric detection in capillary electrophoresis (CE). The gold microelectrodes, in single or twin sets, were obtained from recordable compact discs (gold‐sputtered type), which present highly reproducible surface characteristics. The performance of these electrodes was evaluated by using a home‐made CE equipment. The basic steps for the electrode construction are: drawing on a microcomputer; laser printing of the design on wax paper; heat‐transfer of the toner onto the gold surface of a peeled recordable compact disc (CD‐R); etching of the gold layer from unprinted regions; removal of the toner with a solvent; sealing of unused electrode areas with varnish. One electrode at a time was connected to a potentiostat (or two, to a bipotentiostat) and operated in a wall jet configuration relative to the CE capillary outlet. The amperometric signals were integrated for quantification purposes. Repetitive injections ( n = 10) of a mixture containing iodide, ascorbic acid, dipyrone, and acetaminophen (20, 200, 500, and 100 μ M ), presented relative standard deviations of 2.9, 4.5, 6.1, and 4.0%, respectively. For these analytes, the detection limits (S/N = 3, 30 s of 100 mm hydrodynamic injection) were 0.1, 0.5, 3.1, and 1.1 μ M , respectively.