Selective electrochemical detection using a split disk array electrode in a thin-layer radial flow system

An eight-sector array (split disk) electrode was designed for a low now rate (< 100 mu L/min) amperometric detector, This electrode was fabricated photolithographically for dimensional accuracy and reproducibility. This array of a pie-shaped electrode was combined with a thin-layer radial now cell, and a conversion efficiency of 94% was achieved at the lowest now rate tested (0.01 mL/min). Each electrode worked free from the effects of electrochemical reactions of the other electrodes. A coulometric hydrodynamic voltammogram of reversible redox species obtained using this system exhibited a Nernstian curve, These properties enabled this electrochemical detector to be used for determining the ratio of two redox species (redox potential difference approximate to 100 mV) with small injection volume (5 mu L).