Natural monocrystalline pyrite, chalcopyrite and galena as electrochemical sensors for potentiometric redox titrations in acetonitrile

Natural monocrystalline pyrite, chalcopyrite and galena have been used as new indicator electrodes for potentiometric redox titrations of ferrocene, tetrabutylammonium iodide, thiourea and hydroquinone in acetonitrile. Copper(II) in acetonitrile was employed as the titrating agent. The results obtained by using these electrodes were compared with those obtained by the application of a platinum electrode under the same conditions and good agreement, reproducibility and accuracy were obtained. The standard deviation for the determinations was less than 0.58% when the amount of the respective compound lay in the range 7–47 mg.Possible relationships between the properties of the electrodes material and their application as indicator redox electrodes are briefly considered. All the electrodes showed a relatively fast response time and can be used without any time limit or without considerable divergence in the potentials.