PULSED COULOMETRIC DETECTION BY AUTOMATIC DISCARD OF BACKGROUND SIGNAL IN ANODE DETECTION OF SURFACE OXIDATION CATALYST FOR GOLD ELECTRODE IN PASSAGE CELL

摘要

PURPOSE: To make it possible to improve the sensitivity and detecting capacity by electrochemically detecting analyte in liquid chromatograph environment. CONSTITUTION: A method for electrochemically detecting using the anode cleaning and cathode reactivating of an electrode surface is used in a liquid chromatograph environment. For example, a multistage potential waveform having a periodic potential change which has a first initial potential value E1 is generated for a first time period td so that the periodic waveform can exist in the state that the electrode surface has no oxide. Then, the value E1 is advanced to second further higher value E1 ' for a time period ts so that the formation of surface oxide takes place by the simultaneous electric catalytic oxidizing reaction of solubility and/or adsorption analyte, and the value E1 is returned to the potential value for a holding time period th so that the entire oxide formed during the potential change to the second value E1 ' is removed from the electrode surface in a cathode manner.