The electron transfer kinetics, and hence the current response, of redox-active species can be dramatically affected by the condition of the surface of the working electrode. Pretreatment of the electrode surface may therefore be necessary in order to obtain reproducible results.
If rinsing the electrode surface with water and/or methanol is insufficient to remove adsorbed species and restore the working electrode to prime condition, then hand polishing may be required using the PK-4 polishing kit. The polish suspensions are applied to fabric pads attached to glass plates. The progression of polishing should always proceed from coarse to fine materials, with thorough rinsing and a change of pads between each step.