A new polarography was studied with dropping carbon fluid electrode (DCFE), composed of graphite powder and low-viscosity liquid paraffin. By using a stainless steel capillary with 0.37 mm inner diameter and a very dense electrolyte solution of saturated CsCl (similar to 10 M), nearly spherical carbon drops of about 2 mm at the maximum size were obtained reproducibly. Well-defined polarograms of ferrocenecarboxylate (FcCOO(-)) with clear limiting currents were observed at this dropping electrode. The slope of the log plot of the polarogram was 66.6 mV, which was dose to the theoretical value of reversible wave (592 mV at 25 degrees C). By achieving the nearly reversible polarographic wave, limiting currents could be observed more clearly than our previous study, in which broadened polarograms had been obtained due to a considerable IR drop at high concentrations. Potential of zero charge of DCFE was also measured and discussed. (C) 2016 Elsevier B.V. All rights reserved.