| 摘要 |
PURPOSE:To detect the concentration of a metal ion by adding a complexing agent to a liquid while measuring the concentration thereof in the liquid. CONSTITUTION:A fixed amount of a liquid to be detected is placed into a reactor 3 and the concentration of a metal ion in the liquid is measured as potential of an ion selective electrode 8 while adding a solution 6 (of known concentration) of a complexing agent which reacts the metal ion to form a complex to the liquid gradually. During the adding of the complexing agent, a time at which the potential of the electrode 8 changes suddenly is checked to detect the concentration of the metal ion from the amount of the complexing agent added. The logarithm of the concentration thereof has a linear relationship with the potential of the ion-responsive electrode and the potential of the electrode suddenly changes at a point where the metal ion is equivalent to the complexing agent thereby enabling accurate measurement of the concentration of the metal ion in the liquid being detected. |
