| 摘要 |
A method of measuring pH of aqueous liquid with little or no buffer present uses an electrochemical sensor which has an electrode comprising a substrate 45, at least one redox active compound 46 on the substrate which is able to undergo a redox reaction involving both electron and proton transfer, such as an aromatic quinone, and a covering layer 49 over the redox active compound. The covering layer allows the passage of hydrogen ions to the redox active compound(s) through the covering layer by exchange of hydrogen atoms along a sequence of groups connected by hydrogen bonds. The covering layer may be formed from a polymeric compound, such as polyvinyl alcohol, or surfactant or lipid compounds. Such an electrochemical sensor may be used for pH measurement in computer controlled equipment for processing an aqueous liquid. |
