The Moral Decision

The graphite electrode.An improved technique for voltammetry and chronopotentiometry

“…Impregnating the electrode with wax lowered residual currents without affecting faradaic currents to the same extent, which resulted in greatly increased sensitivity (8,9,25). The most precise voltammetric results reported to date (16,17) were based on use of an evacuation technique to ensure complete penetration of the wax into the graphite rod, and of a small manual lathe to prepare a fresh surface for each run; current measurement reproducibility was ex-cellent with the ferri-ferrocyanide system, which appeared to behave reversibly. The wax-impregnated graphite electrode has been employed for chronopotentiometric as well as voltammetric studies of several organic and inorganic species (6,7).…”

“…PRELIMINARY STUDIES Preliminary chronopotentiometry with the lathed, wax-impregnated graphite electrode was discouraging in that the precision reported for such electrodes in voltammetry (16,17) could not be duplicated even when repeated runs were made at the same concentration and current levels. Better results could be attained if the electrode were submerged in the solution for about 15 minutes before electrolysis; it did not seem to matter whether or not the electrode surface was pretreated electrolyticaliy during this period.…”

“…Previous workers (16,17) have warned against the adherence of air bubbles on the graphite electrode surface, but have neither stressed the importance of this factor nor proposed a remedy. Insertion of the electrode in the solution for 15 to 20 minutes before each run to alleviate the wetting problem is not only time-consuming, but may allow time for ragged penetration of the solution into the graphite.…”