Natural monocrystalline pyrite as electrode material for potentiometric titrations in water

The possibility of applying natural monocrystalline pyrite as sensor for the potentiometric titration of acids in water was investigated. The potential of this electrode in aqueous solutions exhibits a sub-Nernst dependence. In fresh solutions the slope (mV/pH) is 33.9. The potential jumps at the titration end-point obtained in titrations of HCl, H(3)PO(4) and CH(3) COOH do not differ much from those obtained by the application of the glass electrode as the indicator one. The potentials in the course of the titration and at the titration end-point (TEP) are rapidly established. The results obtained in the determination of the investigated acids deviated for 0.16-0.34% with respect to those obtained by using the glass electrode as the indicator one.