| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for accurately determining the quantity of a chemical substance contained in a sample solution with an extremely low concentration of 1×10M or less.SOLUTION: There is provided a measurement system which includes a counter electrode 13, a first reference electrode 12, a first working electrode 11a, a second working electrode 11b, and a second reference electrode 14. Subsequently, a voltage (V1>V2) of V1 volt and V2 volt respectively is applied to the first working electrode 11a and the second working electrode 11b for a first predetermined period t1. When a first predetermined period t1 has elapsed, the application of the voltage to the second working electrode 11b is stopped. A sample solution 15 is left for a second predetermined period t2. Finally, a voltage difference &Dgr;E between the second working electrode 11b and the second reference electrode 14 is measured and the concentration of the chemical substance is calculated based on the &Dgr;E. |
