Method and apparatus for the analysis of solution adjacent an electrode
AssigneeThe Ohio State University Research Foundation
InventorsRichard L. McCreery, Clyde W. McCurdy, Paula J. Rossi
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Abstract
Electrochemically generated chromophores are measured by passing a beam of electromagnetic radiation parallel and close to the surface of the electrode at which they are being generated, and collecting the diffracted radiation. The response is so rapid (.about.0.025 sec.) that modulation is practicable and the path length, which is set by the thickness of the electrode, is much greater than in optically transparent electrodes, thus rendering the method very sensitive to weak chromophores or low concentrations.
Claims25
A method for the analysis of a layer of solution adjacent a surface of an electrode, said solution being capable of undergoing an electrochemical oxidation or reduction which alters its absorbance of electromagnetic radiation of at least one wavelength, said method comprising:
- passing a beam of electromagnetic radiation at least part of which is of said wavelength across and substantially parallel to said surface;
- measuring the radiation diffracted at an angle to said beam by means of radiation measuring means lying outside said beam;
- altering the potential of said electrode, thereby causing at least part of said solution to undergo said electrochemical oxidation or reduction;
- again passing said beam across and substantially parallel to said surface;
- and
- again measuring said radiation diffracted at an angle to said beam by means of radiation measuring means lying outside said beam.
Apparatus for analysis of a layer of solution adjacent a working electrode, said apparatus comprising;
- a working electrode;
- a counterelectrode;
- means for applying a variable potential between said working electrode and said counterelectrode;
- a beam generator for passing a beam of electromagnetic radiation across and substantially parallel to the surface of the working electrode;
- a container for retaining liquid in contact with the surface of the working electrode;
- a converging lens disposed adjacent said working electrode on the opposed side thereof from said beam generator and
- a radiation detector disposed substantially in the focal plane of said lens for detecting radiation diffracted at an angle to the beam, said radiation detector being disposed outside said beam.
Dependencies are inferred from the claim text.