Читать книгу Electroanalytical Chemistry - Gary A. Mabbott - Страница 18

Potentiometry is a category of electroanalytical techniques that involves measuring the potential energy difference that develops at the boundary between a sensor and the sample solution as a function of the analyte concentration in the sample solution in which current does not flow. Alternatively, one can use an external power source, such as a battery, to impose a voltage to an electrode surface. This strategy drives an electron transfer reaction between an electrode and analyte in solution at select voltages. Current is measured in these experiments, and it may be proportional to analyte concentration under the right conditions. Voltammetry is a category of methods that measure the current in response to applying a range of voltages to the electrode/solution interface. The term “voltammetry” implies that the voltage is scanned in some manner. If the voltage is held at a constant value while measuring the current, the technique is called amperometry.