GB2012435A - Electrochemical Measuring System - Google Patents

Abstract

An electrochemical measuring system which determines selected substances in a sample solution is provided. The system includes a cell which is constructed for simultaneous measurement on at least two electrodes of at least two electrolytic potentials with reference to a reference potential. In a preferred form the cell comprises a hollow, cylindrical body formed of an electrically insulating material. The electrode is open at least at one end and has a generally smooth cylindrical inner surface. A plurality of electrically discrete active electrode segments are mounted on the inner surface of the electrode with their active surfaces substantially flush with the generally smooth cylindrical inner surface. Completing the electrochemical measuring system are a stirring means for creating a relatively high degree of mixing adjacent the electrode active surfaces, means for charging liquid samples to the cell, and means connecting at least two of the electrically discrete active electrode segments to different electrical potentials. In use a sample to be tested is charged to the cell, and stirring is commenced. One of the electrode segments is held at a potential at which a selected substance of interest and also one or more interfering substances responds, while another of the electrode segments is held at a potential at which only the interfering substances respond. The presence of a substance of interest can be determined by subtracting the signals from the one and another electrode segments, and its quantity determined by integrating the signal difference. <IMAGE>