`The technique of rapid scanning amperometric detection is described.
This method combines an ability to perform rapid potential scanning of
the analyte, which facilitates the construction of a three-dimensiona
l current trace at different potentials versus time, with the techniqu
e of pulsed amperometric detection, which allows the application of cl
eaning/activation pulses to the detection electrode. Unlike pulsed vol
tammetry with scanning voltammetric detection, which is described by o
ther workers, this method employs a true microelectrode as the detecto
r (an array of eight 5 mu m band electrodes). Rapid scanning and pulsi
ng is possible without interference from non-faradaic charging current
s that may mask the faradaic signals. Catecholamine separation by high
-performance liquid chromatography was selected as a model system to d
emonstrate the detection method in flowing streams. Measurements were
made using a series of different pulsing rates; no distortion of the v
oltammetric signal was observed up to a pulsing rate of 20 ms, 50 Hz (
effective scan rate, 4.4 V s(-1)). Comparison with a series of d.c. am
perometric measurements at a set of different potentials demonstrates
the scope of analyte information that this technique makes available,
Analyte data can be obtained in both electrochemical and chromatograph
ic domains.