Microelectrodes
Microelectrodes
This thesis contains two sections. The first considers ways in which microelectrodes might be used to simplify laboratory based analytical procedures for silicate and/or phosphate in water samples. Silicate and phosphate can be electrochemically determined following an initial treatment of the sample with an acidic molybdate solution which leads to their conversion into the Keggin anions, SiMo12O404- and PMo12O403-. Their voltammetry was defined at gold microdisc electrodes and it was possible to define conditions where the measurement of the steady state limiting currents provided rapid, simple and convenient methods to determine Si or P in waters in the presence of 40 μM excess of the other with detection limits < 1 μM. Selectivity in the analyses of the two species was introduced by modification of the solution (e.g. variation of the pH or the addition of solvents and complexing agents) or by exploiting differences in the kinetics of formation of the two electroactive species in aqueous solution.
The second describes the principle of a new design of amperometric gas sensor. In this design non-porous electrodes are fabricated onto the atmosphere side of an ion conducting medium, so that electrodes are fabricated onto the atmosphere side of an ion conducting medium, so that electron transfer of the gas occurs at the three-phase interface between electrode, ion conductor and atmosphere. With this design the system should approximate to a line electrode. A preliminary study of the novel devices is reported during using the oxidation of sulphur dioxide as the model reaction. The cell showed the expected voltammetry in contact with N2 and N2 + SO2 atmospheres, and conditions where the amperometric response was proportional to the SO2 content could be defined. The response time of the cell was rapid and 300 ppm SO2 was well above the detection limit.
University of Southampton
Hodgson, Alexia Wilgith Elsa
1998
Hodgson, Alexia Wilgith Elsa
Hodgson, Alexia Wilgith Elsa
(1998)
Microelectrodes.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
This thesis contains two sections. The first considers ways in which microelectrodes might be used to simplify laboratory based analytical procedures for silicate and/or phosphate in water samples. Silicate and phosphate can be electrochemically determined following an initial treatment of the sample with an acidic molybdate solution which leads to their conversion into the Keggin anions, SiMo12O404- and PMo12O403-. Their voltammetry was defined at gold microdisc electrodes and it was possible to define conditions where the measurement of the steady state limiting currents provided rapid, simple and convenient methods to determine Si or P in waters in the presence of 40 μM excess of the other with detection limits < 1 μM. Selectivity in the analyses of the two species was introduced by modification of the solution (e.g. variation of the pH or the addition of solvents and complexing agents) or by exploiting differences in the kinetics of formation of the two electroactive species in aqueous solution.
The second describes the principle of a new design of amperometric gas sensor. In this design non-porous electrodes are fabricated onto the atmosphere side of an ion conducting medium, so that electrodes are fabricated onto the atmosphere side of an ion conducting medium, so that electron transfer of the gas occurs at the three-phase interface between electrode, ion conductor and atmosphere. With this design the system should approximate to a line electrode. A preliminary study of the novel devices is reported during using the oxidation of sulphur dioxide as the model reaction. The cell showed the expected voltammetry in contact with N2 and N2 + SO2 atmospheres, and conditions where the amperometric response was proportional to the SO2 content could be defined. The response time of the cell was rapid and 300 ppm SO2 was well above the detection limit.
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Published date: 1998
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Local EPrints ID: 463212
URI: http://eprints.soton.ac.uk/id/eprint/463212
PURE UUID: 75e86e46-53f3-4f63-ac02-62b135d8f9b3
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Date deposited: 04 Jul 2022 20:47
Last modified: 04 Jul 2022 20:47
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Author:
Alexia Wilgith Elsa Hodgson
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