Differential pulse polarography at a dropping carbon fluid electrode

Differential pulse polarography was performed with a dropping carbon fluid electrode (DCFE). For the periodic renewal of DCFE, a new type of drop knocker was devised. Unlike those which knock on a capillary for a dropping mercury electrode (DME), this device is based on water jet generation. The water jet given from a nozzle placed nearby a capillary for DCFE was able to blow off the carbon drop periodically. The influence of convection on current signals was only significant within 1 s after the removal of the carbon drop. The comparison of the results of differential pulse and DC polarography showed that differential pulse polarography was superior to DC polarography in terms of the limit of detection.