PULSED ELECTROCHEMICAL DETECTION AT THE RING OF A RING-DISK ELECTRODEAPPLIED TO A STUDY OF AMINE ADSORPTION AT GOLD ELECTRODES

Results are shown for application of a Au-Au rotated ring-disk electro de to an investigation of the adsorption and desorption of model organ ic amine compounds in alkaline media. Aliphatic amines are not detecte d at constant potential, and therefore, a multistep potential wave for m is applied at the ring electrode to achieve their pulsed electrochem ical detection. On the basis of the ring-disk results, the potential-d ependent nature of amine adsorption and desorption at the An disk elec trode is easily evaluated. Furthermore, the significance of this infor mation is demonstrated for the optimization of a PED wave form applied for the detection of aliphatic amines separated by high-performance l iquid chromatography. Proper choice of the potential for oxide reducti on in the PED wave form allows for simultaneous preadsorption of amine compounds with the benefit of enhanced detection sensitivity.