| 摘要 |
A high sensitivity multiple waveform voltammetric method and instrument are provided for use in electrochemical and other applications. The method consists of applying one or several variable potential excitation signals between electrodes of an electrochemical cell to produce an electrochemical reaction in the solution. The excitation signals include a DC bias potential increasing cyclically by a potential step to form a potential staircase signal sweeping across a potential domain, and a number of pulse trains either of opposite polarity or shifted in potential per potential step. An electric current derived from a diffusion flux of ions through the solution is measured as a result of the applied excitation signal. The instrument is adapted to perform the method, and is provided with an accurate and low noise signal generator circuit, a circuit for reducing a double layer capacitive effect in the cell, a potentiostat having a virtual mass counter electrode, a feedback circuit for compensating an ohmic drop in the cell, and an integrator circuit for integrating the current signal produced by the cell. |
