VOLTAMMETRY WITH AN ION-SELECTIVE MICROELECTRODE BASED ON POLARIZABLE OIL-WATER INTERFACE

Theoretical expressions are presented for the potential step chronoamperometry, normal pulse voltammetry and cyclic voltammetry of the ion-transfer at an ion-selective microelectrode in which a polarizable nitrobenzene/water interface is formed at the tip of a micropipet of mu-m-order diameter with the nitrobenzene phase inside the micropipet. Experiment includes the ion transfer voltammetry of acetylcholine at the microelectrode. The experimental results are well explained by the theoretical predictions. Stripping voltammetry with the microelectrode is also studied; this proved to be promising for determination of acetylcholine at micromolar concentration levels.