| 摘要 |
<p>A method of determining chemical oxygen demand (COD) of a water sample which is useful in a probe configuration includes the steps of a) applying a constant potential bias to a photoelectrochemical cell, having a photoactive working electrode optionally a reference electrode and a counter electrode, and containing a supporting electrolyte solution; b) illuminating the working electrode with a light source and recording the background photocurrent produced at the working electrode from the supporting electrolyte solution; c) adding a water sample, to be analysed, to the photoelectrochemical cell; d) illuminating the working electrode with a light source and recording the steady state photocurrent produced with the sample; e) determining the chemical oxygen demand of the water sample using the formula (I): where d is the Nernst diffusion layer thickness, D is the diffusion coefficient, A is the electrode area, F the Faraday constant and iss the steady state photocurrent. The method can accommodate a broad range of light intensity and pH.</p> |
