Hydrodynamic modulation voltammetry with an oscillating microjet electrode
UNSPECIFIED. (1999) Hydrodynamic modulation voltammetry with an oscillating microjet electrode. ANALYTICAL CHEMISTRY, 71 (20). pp. 4642-4648. ISSN 0003-2700Full text not available from this repository.
A new method of hydrodynamic modulation voltammetry (HMV) is introduced, based on the microjet electrode (MJE) with an oscillating nozzle position. In MJE-HMV a jet of solution is fired at high velocities from a nozzle (with a typical diameter in the range 25-50 mu m) onto the surface of a disk ultramicroelectrode (UME). The mass transport rate to the electrode is modulated by oscillating the lateral position of the jet between two different coordinates: one where the jet impinges directly on the electrode surface and the other where the flowing stream (largely) misses the electrode. The resulting modulated (transport-limited) current in phase with the moving jet is quantitative and discriminates effectively against background processes. Studies of iridium (III) hexachloride (IrCl63-) oxidation at a Pt MJE serve to demonstrate the general capabilities of the technique. For this system, detection limits are estimated to be similar to 5 x 10(-9) mol dm(-3). In its present form, modulation frequencies of as much as 20 Hz can be successfully employed without serious attenuation of the current signal, and there is scope for further improvement through the use of smaller nozzles and electrodes and piezoelectric positioners with improved frequency responses.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||ANALYTICAL CHEMISTRY|
|Publisher:||AMER CHEMICAL SOC|
|Date:||15 October 1999|
|Number of Pages:||7|
|Page Range:||pp. 4642-4648|
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